1

Chapter 1Principle and Characteristics of Induction MotorsChapter 2Inverter Principle and CharacteristicsChapter 3Operation CharacteristicsChapter 4Inverter Drive Units Selection

Chapter 5Inverter Functions and AdvantagesChapter 6Inverter Drives Precautions Chapter 7Harmonics, Noise & Surge VoltageChapter 8Maintenance and Inspection

2

Market of General purpose Inverters

Introduction

3

109109109109

127127127127

144144144144151151151151

166166166166

120120120120

109109109109118118118118

98989898

93939393

840751767

715644

0000

50505050

100100100100

150150150150

200200200200

250250250250

300300300300

350350350350

2002200220022002 2003200320032003 2004200420042004 2005200520052005 2006200620062006 2007200720072007 2008200820082008

0000

100100100100

200200200200

300300300300

400400400400

500500500500

600600600600

700700700700

800800800800

900900900900

1000100010001000

202225

262 260

Drives Industry Market Growth in Japan

Actual Estimate

Hu

ndred

millio

n ye

n

U

n

i

t

s

x

1

0

,

0

0

0

Drives up to 75 kW

Hundred million

Tens of thousands

ExportDomestic

23% 24%

27% 26%

3%

51%

15%

31%up to 0.75 kW0.75 kW to 4 kW4 kW to 15 kW15 kW to 75 kW

Units Amount

Shipments by capacity in 2006

Data from JEMA

286

4

Yaskawa14.1%

A13.0%

B12.8%

C12.5%

D11.4%

E8.6%

G2.8%

F7.8%

H1.7%

Others15.2%

\ 395.9 billion2006

17.4%

15.8%12.8%

17.0%11.0%

Japan

USAEurope

China Asia

*Data has been gathered and analyzed by Yaskawa.

No.1 Global Share(fiscal year 2006)

Global Share by Region

5

Yaskawa Drives BusinessAs a drives manufacturer, we provide overwhelmingly

powerful products and application solutions.

Drives SpecialistsOur vast engineering skills, we have earned us the reputation

among our customers as specialists who possess

progressive technology and build long-

lasting cooperative relationships.

74Worlds 1st Transistor InverterVS-616T

747474

74 808080

80 909090

90858585

85 000000

00959595

95 050505

05

85Worlds 1st Digital ControlVS-616H

79Worlds 1st Vector ControlVS-626TV

88Worlds 1st IGBT Low-noise InverterVS-616GLN

94Worlds 1st Ultra-compact ASIPM InverterVS mini C

95Worlds 1st Vector Control General-purpose InverterVS-616G5

00Worlds 1st 3-level Control General-purpose InverterVarispeed G7

06Worlds 1st Matrix Converter DriveVarispeed AC

VS

VSVS

VS-

--

-616H

616H616H

616H

VS

VSVS

VS-

--

-616G

616G616G

616G

VS

VSVS

VS-

--

-616G

616G616G

616G

VS

VSVS

VS-

--

-616G3

616G3616G3

616G3

VS

VSVS

VS-

--

-616H3

616H3616H3

616H3

VS

VSVS

VS-

--

-606PC3

606PC3606PC3

606PC3

VS

VSVS

VS-

--

-606V7

606V7606V7

606V7

VS mini J7

VS mini J7VS mini J7

VS mini J7

Varispeed F7S

Varispeed F7SVarispeed F7S

Varispeed F7S

Varispeed L7

Varispeed L7Varispeed L7

Varispeed L7

Varispeed

Varispeed Varispeed

Varispeed

V7 pico

V7 picoV7 pico

V7 pico

Varispeed F7

Varispeed F7Varispeed F7

Varispeed F7

S

a

l

e

s

V1000Release

6

YASKAWA ELECTRIC UK LTD. (YGB)YASKAWA ELECTRIC EUROPE GmbH (YEG)

YASKAWA ELECTRIC AMERICA,INC. (YEA)Buffalo Grove Facility

Global Sales Offices and Production Facilities

YASKAWA ELECTRIC AMERICA,INC. (YEA)New Berlin Wisconsin Panel Facility

YASKWA ELECTRIC KOREA CORPORATION (YEK)

YASKAWA ELECTRIC (HK) COMPANY LIMITED (YHK)

YASKAWA ELECTRIC (SHANGHAI) CO.,LTD. (SHANGHAI)

SHANGHAI YASKWA DRIVE CO.,LTD. (SYD)

Yaskawa Electric Taiwan Corporation (YTW)

YASKAWA ELECTRIC (SINGAPORE) PTE.LTD. (YSP)

Inverter Plant (V)

YASKAWA ELECTRIC CORPORATION (YEC)

YASKAWA ELETRICO DO BRASIL COMERCIO LTD.A. (YEB)

: Sales office: Production facility

7

Chapter 1Principle and Characteristics

of Induction Motors

8

Motors

Motors for motive power

Motors for dynamic response

DC motors (series, shunt, compound)

AC motors

Induction motors(Squirrel-cage, wound rotor type)

Synchronous motors(Magnet type, field winding type)

Motors with eddy-current coupling(VS-MOTOR)

ServomotorsDC servomotors

AC servomotors(SM, IM types)

Types of Motors

9

Configuration

Rotor end ring

SecondaryConductor

(b) Squirrel-cage Rotor(Excluding Iron Core)

(a) Configuration of Squirrel-cage Induction motor(Example of Totally-enclosed Externally-cooled Type)

Outputshaft

frame box

Externalfan

Bearing

Internalfan

Rotor End ring

Fan coverRotor

Iron core

Center height(Motor frame No.)

Bracket

10

Magnetic field (Flux density B (wb/m2) )

N

SBBBB

FFFF

IIII

Force(F)Force(F)Force(F)Force(F)

Magnetic Magnetic Magnetic Magnetic

Field(B)Field(B)Field(B)Field(B)

Current(I)Current(I)Current(I)Current(I)

F

I

B

Force(F)Force(F)Force(F)Force(F)

Magnetic Magnetic Magnetic Magnetic

Field(B)Field(B)Field(B)Field(B)

Current(I)Current(I)Current(I)Current(I)

Flemings Right-hand Rule Flemings Left-hand Rule

11

ARAGOs Disc(Disc rotates following magnet rotation.)

Induction Effect of Rotating Magnetic Field

Rotary Shaft

Principle

N

S

Permanent MagnetIron Disc

S

N

NS

NSFlux

12

Current Direction

Direction of Magnetic Flux

Right Screw

A. Right hand screw Rule

Current Direction

B. Coil Current and Magnetic Flux Directions

Direction of Magnetic Flux

Beginning of Coil Winding

End of Coil Winding

Magnetic Flux Generated by CurrentDirection of Mag. flux from front to back of paper face

Direction of Mag. flux from back to front of paper face

13

Three-phase motors use three-phase alternating current to create a rotating magnetic field.

U

V

W

U

Phase U Phase V Phase W

VWU

V W

0 pi 2pi

Principle of Rotating Magnetic Field (2 Pole)

U, V, W : START of Coil

U,V,W: END of Coil

1 Cycle

3-phase AC (Current)

Direction of Magnetic

Field

(a) Three-phase Alternating Current (Power Supply) and Magnetic Field Direction

Induction Motor

14

P o w er S u pp ly F re quency (f) N o . o f P o les

(P )

N o . o f C o ils pe r

P hase 50 H z 60 H z

2 1 3 000 3 600

4 2 1 500 1 800

6 3 1 000 1 200

8 4 7 50 9 00

S NS N

N S2p 4p

8p6p(a) Synchronous Speed (min-1)

(b) Number of Poles (p)

Number of Poles and Synchronous Speed

S N

S N

N S

S NN

NNS

S

S

15

Rotating Magnetic Field of a 4-pole Motor

(a) Coil Arrangement(b) Three-phase

Alternating Current

U

V

W

Phase U Phase V Phase W

16

The above equation can be changed into the following one.

Therefore:

Synchronous SpeedThe speed at which the magnetic field rotates is called synchronous speed (NS), which depends on the number of magnetic poles p , that depends on the configuration of the motor stator winding, and power supply frequency f .

Rotating SpeedRotor speed N ( min-1 ) is a little slower than synchronous speed is a little slower than synchronous speed is a little slower than synchronous speed is a little slower than synchronous speed Ns . This amount is called . This amount is called . This amount is called . This amount is called slipslipslipslip, which is defined as follows:, which is defined as follows:, which is defined as follows:, which is defined as follows:

S

S

NNN

S

=

( )SSNN = 1

(((( ))))N fp

S==== 120 1

pfN S 120= NS : Synchronous speed ( min-1 )

f : Power supply frequency (Hz)( min-1 )

( min-1 )

Ns : Characteristic value dependingon motor specifications

s : Value varying on the load size

Induction Motor Speeds

17

360018000[With 4 poles at 60 Hz ( min-1 )] - 1800

Characteristics

Torque

Rated Current

Stalling Torque

Rated Torque

Slip (Rating)

Motoring Area

Rated Speed

( PLU GGING )

No-load Current

Current (%)

Starting Current

Starting Torque

(Induction Generator)Regenerative Braking AreaReverse Phase Braking Area

Ns

18

-1

Control Method

Load Torque

The intersection of the motor generating torque and the load torque becomes the operation speed.

To change the induction motor speed

Changing p(Pole change motor)

Changing s(Primary voltage control)

Changing s(Secondary resistance control)

Changing f

Number of Poles Large

Secondary Resistance Large

Voltage Small Frequency Small

(Primary frequency controlinverter drives)

19

2. Applied ModificationGeared motors Output shaft torque increased

Brake motorsQuick brakeAG brake motors

Explosionproof motorsIncreased safety explosionproof motorsExplosionproof motors

Types of Inverter Motors

Fan Cover External FanExternal Fan (-K)

Pulse Generator (-M)

1. Inverter Drive Motors

FEQ-X, FEFFEK-I FEK-IK FEK-IKM

(With electric fan) (With electric fan and PG)

Totally-enclosed

Model EEK-IM(With PG)

Totally-enclosedFan-cooled Type

Totally-enclosedFan-cooled Type

Totally-enclosed Fan-cooled Type

20

The following shows the relation between the magnetic flux, voltage and frequency.

ExampleWhen speed is reduced to the half (60 Hz to 30 Hz), according to the above equation, set the inverter output voltage and output frequency so that the magnetic flux will be constant.

ttanCons)Hz(30)V(100

)Hz(60)V(200

fV

===

200

100

0 30 60Frequency (Hz)

In actual operation, voltage at low frequency must be increased by 150% to 200% in order to compensate for voltage drop in the motor.

Motor Characteristics at Inverter Drives

Voltage (V)

Magnetic Flux Voltage VFrequency f = Constant

21

The following shows the equation of motor rated torque.

ExampleIn case of a motor of 7.5 kW, 4 poles, rated speed 1740 min-1

Rated torque TM 974 Motor rated output P (kW)

Rated speed N (min-1) (kgfm)

Rated torque TM 974 7.51740 (kgfm) 4.19

Rated torque TM Motor rated output P (W)

Rated speed N (min-1) (Nm)602pi

Rated torque TM 7.5103

1740 (Nm) 41.2602pi

Motor Rated Torque

22

When load torque variesAs the load torque becomes greater, the motor speed decreases (or slip becomes greater).

At this time, the greater the load torque the greater the motor current.

When the motor applied voltage variesThe motor generating torque is in proportion to the square of voltage.As the voltage becomes smaller, the speed decreases (or slip becomes greater).

Voltage Fluctuation and Speed Changes

Load Fluctuation and Speed Changes

Motor Speed VariationOutput Torque

Speed

Load Large

Load Small

Speed

Voltage Large

Load Constant

T

o

r

q

u

e

Voltage Small

T

o

r

q

u

e

23

Inverter output voltage does not exceed power supply voltage.

Therefore, output voltage becomes constant in the range exceeding frequency 50 Hz or 60 Hz (base frequency).The following equation shows the relation between motor voltage (V), frequency (f) and torque.

IfV

KTorque T = K ConstantConstantConstantConstant CurrentCurrentCurrentCurrent

Since only frequency is changed, torque is reduced in inverse proportion to frequency if the motor current value is the same as shown in the above equation.

This area is called constant output area.

Operations Exceeding 50Hz or 60Hz

24

Chapter 2Inverter Principle and Characteristics

25

Rectifier CircuitConverter Section

DC IntermediateCircuit

Smoothing Circuit Section

Invert ConversionCircuit

Inverter Section

Commercial Commercial Commercial Commercial

PowerPowerPowerPower

AC Power

VariableVariableVariableVariable FrequencyFrequencyFrequencyFrequency

/Variable Voltage AC/Variable Voltage AC/Variable Voltage AC/Variable Voltage AC

Control Circuit Section

M

Motor

VVVF

Inverter Configuration

AC Power

VoltageVoltageVoltageVoltage

CurrentCurrentCurrentCurrent

VoltageVoltageVoltageVoltage

CurrentCurrentCurrentCurrent

VoltageVoltageVoltageVoltage

CurrentCurrentCurrentCurrent

26

Voltage

Current

Voltage

Current

Voltage

Current

IMUVW

Power source

Contactinput

ForwardReverse

Multi-functioninput

Analog input

Pulse train input

I

n

p

u

t

s

i

g

n

a

l

O

u

t

p

u

t

s

i

g

n

a

l

Actual inverter circuit

Diode Transister

Register

Capacitor

Digitaloperator

Pulse train output

Analog monitor

Multi-unction contact output

Multi-function analog output

Contact output

Open collector output

Fault output

RST

SC

Digitaloperator

AC DC AC

27

0

Current wave

R

S4

S3S1

S2

DC Power Supply

S1 S4 ON S1 S4 ON

S2 S3 ON

How to Make AC

ON ON

ON

SwitchesS1, S4

S2, S3

Ed

Principle of Single-phase Inverter

+Ed

-Ed

28

Basic Circuit of 3-phase Inverter

S1S2S3S4S5S6

U-V

V-W

W-U

0 60 120 180 240 300 360 60 120 180 240 300

MotorU

WV

PPPP

NNNN

S3S1 S5

S4 S6 S2

DCpowersource

Principle of generating 3-phase alternating current

SwitchingPattern

AC Output

a

Interval a

29

IM

Motor

3-phase AC

EdDC Power Supply

Basic Circuit of Transistor Inverter

+Ed

30

~

P

N

C

MC

R

D3D2D1

D6D5D4

V

V

Ed

Vs

In-rush Current Suppression Resistor

Vs1.35Vspi

23dE =

Converter Sectionand In-rush Current Suppression

V

31

Name Diode Thyristor GTO

(Gate Tum Off Thyristor)

Bipolar Power Transistor

IGBT (Insulated Gate Bipolar

Tr.)

Power MOS FET (Power Metal Oxide

Semiconductor. Field Effect Tr.)

S

y

m

b

o

l

C

h

a

r

a

c

t

e

r

i

s

t

i

c

s

V

o

l

t

a

g

e

,

C

u

r

r

e

n

t

W

a

v

e

f

o

r

m

F

e

a

t

u

r

e

s

,

A

p

p

l

i

c

a

t

i

o

n

General high-voltage, large-current rectifier circuits

High-voltage, large-current converter section Inverter section, chopper section attached with commutation circuit

High-voltage, large-current inverter section, chopper section

Medium voltage, medium current high-speed switching, inverter section

Medium voltage, medium current high-speed switching, inverter section

Low-voltage, small- current high-speed switching, inverter section

Main Semiconductor Power Elements Used for Inverters

Anode

Cathode

Gate

Collector

Base

Emitter

Drain

Gate

Source

32

Control Method Output Frequency Features

PAM MethodPAM MethodPAM MethodPAM Method

(Pulse Amplitude Modulation)

Voltage control is needed for the converter.

Motor current distortion is excessive, resulting in torque ripple.

PWM MethodPWM MethodPWM MethodPWM Method

(Sinusoidal Wave Approximate)

PWM: Pulse Width Modulation

When the above Output power frequency is 60 Hz, the number of pulses per cycle is 14. Therefore, carrier wave (carrier frequency) is obtained as 6014 = 840 Hz. Since the actual inverter has this carrier frequency of 15 kHz, the number of pulses per cycle is 250 pulses (1500060).

Frequency and voltage can be controlled only in the inverter section.

Smooth operation is possible at a low speed.

EdEd

(Ed: DC voltage)

Output Voltage Waveform

Ed

Ed

Average Output Voltage

Voltage-type Inverter Control Method

33

3-phase Power SupplyIM

Voltage/Current

Detection

N

0 t

Accel/decelInterrupt Signal

V

0f

PWM Signal

GeneratorBaseDriver

VoltageReference

Accel/decel Adjuster V/f Setter

Frequency Reference

Speed (Frequency)Reference

Transistor Base Signal

Current DetectorMotor

InverterConverter

V/f Control PWM Inverter

34

Rated Voltage

Voltage (V)

In Case of Variable Torque Load

In Case of Constant Torque Load

E/f Constant(Constant Magnetic Flux)

Compensation for Motor Primary Winding Voltage Drop

VoltageBias

Frequency f (Hz)Rated Frequency

V/f Constant

V/f control compensates for the voltage drop value of the motor primary winding for the constant E/f (magnetic flux).

Voltage / Frequency Characteristics in V/f Control

35

tN

PWM Controlfdt

Speed Reference

Torque Reference

Accel/decel Adjuster

Speed Feedback Signal

Speed ControllerCurrent Reference Calculator

Current Amplitude Reference

Torque Current Reference

Each Phase Current Reference

MultiplierInstantaneousCurrentControl Circuit

Slip FrequencyCalculation

IM

Exciting Current Reference

Speed/Torque Control Switch

I 2IM

Current Phase Reference

f s fn

3- (or 2-) phase Current Feedback Signal

PG (Speed Detector) (Pulse Generator)

Motor

Current Detector

Inverter

Converter

3-phase Power Supply

I 2

M

Vector Control PWM Inverter

I1

I1

f

36

&I2r1 l1

&E&V&I1

&IMM

r2

12

s

sr

(b) Vector Diagram

& I 2 & I 1

&I 1

&I M

I2 I2

I2

I1

I1

IM

E

IME

I1V

V : Motor terminal voltager1 : Primary winding resistanceE : Motor (internal) induced voltage r2 : Secondary winding resistanceI1 : Motor primary (stator) current l1 : Primary winding leak inductanceI2 : Motor secondary (rotor) currentM : Exciting inductanceIM : Exciting current (exciting current component of primary current) S : Slip

Equivalent Circuit and Vector Diagram

V 1l

1r1I

1I

s

r2

(a) Equivalent Circuit for Motor One Phase

37Open Loop Vector Control

Actual MotorInverter

Motor Control

Virtual Motor

VoltageACMotor CurrentActual Value

Error

Motor CurrentEstimated Value

Observer GainFluxEstimated ValueSpeedEstimated Value

+

-

Flux Observer Block Diagram

38

In Case of V/f Control In Case of Vector Control

V/f control suitable for the motor load characteristics is needed in order to obtain low-speed torque.

Constant calculation using the motor test report or combination by manufacturer is needed.

Varispeed G7Incorporates the auto-tuning program as standard so that no

complicated adjustment is needed. The following three methods are available for the auto-tuning.

1. Stop-type tuning only for line resistance2Stop-type tuning3. Stop-type tuning24Rotation-type tuning

Input the basic numerical values such as motor NP into the inverter so that the motor determines the motor constants required for the vector control by measurement and calculation. This function is called Auto-tuning.

Auto-tuning

39

Varispeed G7

Specifications V/f Control V/f Control with PG FeedbackOpen-loop

Vector ControlFlux Vector

ControlBasic

ControlVoltage/frequency control

(open-loop)Voltage/frequency control with speed

compensation

Current vector control without PG

Current vector control with PG

Speed Detector Not needed

Needed (pulse generator) Not needed

Needed(pulse generator)

Option Card for Speed Detection Not needed Needed Not needed NeededSpeed Control

Range 1:40 1:40 1:200 1:1000

Starting Torque 150% at 3 Hz 150% at 3 Hz 150% at 0.3 Hz 150% at 0 min

-1

Speed Control Accuracy 2 to 3% 0.03% 0.2% 0.02%

Torque Limit Disabled Disabled Enabled EnabledTorque Control Disabled Disabled Enabled Enabled

Typical Applications

Multi-drives Replacement for existing

motor of which motor constants are unknown

Auto-tuning is enabled only for line resistance.

Simplified feedback control

Applications where pulse generator is attached on the machine shaft

Any variable speed drives

Simplified servo drives

High-accuracy speed control

Torque control

Features of Control Mode

40

Chapter 3 Operation Characteristics

41

(a) Proper Acceleration Time (b) Short Acceleration Time

Acceleration

Output Frequency f

Motor speed N

Overload capacity when inverter capacity is equal to motor capacity

Rated Current

Excessive Slip

Overload capacity when inverter capacity is increased

Rated Current

0

0 0

0

42

Inverter Output Frequency[Dotted line shows the set

accel. ratio.]

Motor Speed

Motor Current

Accel. time becomes longer automatically.

Peak current is limited to within the specified value.

Stall Prevention during Acceleration

t

43

Inverter Output Frequency

Load

Stall Prevention during RunningTo avoid overloading by rapid fluid temperature in hydraulic machines. Avoid overloading by

decreasing output frequency.

t

44

DC Voltage

Inverter Output Frequency

Motor Current

RUN Signal

Actual Stall Prevention Function

Edc.

OVOA

45

Set Decel. Time td

Slip(Minus)

N Rapid decelerationSlip: Minus

f

fN,

t

NSlow decelerationSlip: Plus

Deceleration Time td Motor Operation Mode SliptdCoasting to a stop time Motoring (Motoring area) PlustdCoasting to a stop time Regeneration (power generation area) Minus

Deceleration

0

46

Inverter Output Frequency[Dotted line shows the set decel. ratio.]

Motor Speed

DC Voltage

DC bus voltage is limited to within specified value.

Decel. time becomes longer automatically.

Stall Prevention during Deceleration

t

47

t

DC Injection Braking Time

t

DC Current

N

N

t

DC Injection BrakingStarting Frequency

N, f

DC Current

DC Injection Braking Time

N

FF

F

(a) Frequency Deceleration(Example of DC Injection

Braking Before Stop)

(b) All-area DC Injection Braking (c) Coasting to a Stop

DC Injection Braking

0 0 0

N, f N, f

Free Run

48

(a) Commercial Power Operation (b) Inverter Operation

VI

INV input current is a distortional wave current including harmonics. Unified effective current including harmonics is INV input current. Therefore, the power factor expressed by the above equation is not always equal to the value measured with general power factor meter.

Input Voltage / Current WaveformPower Factor =

Active Power Active PowerActive Power + Reactive Power=

3Inverter Input Power

Power Supply Voltage Inverter Input Current=

Apparent Power

49

er es et

er-s er-t es-t es-r et-r et-s

Phase voltage of power source

Phasecurrent PhasePhasePhasePhase----RRRR

The mechanism of harmonics current generating

EDC

Converter

Ver-s

er

es

et

r

s

t

Line voltage ofLine voltage ofLine voltage ofLine voltage ofpower source

PhasePhasePhasePhase----SSSS

PhasePhasePhasePhase----TTTT

50

*1. The connection cable between the reactor and the inverter must be 5 m or less, the shorter the better. The size must be equivalent to the power supply cable or larger.

*2. Models of 18.5 to 75 kW (200-V class) and 18.5 to 160 kW (400-V class) are incorporated with DC reactors. The power factor improvement is more than 93%.

*3. The inverter power supply power factor is normally approx. 60 to 90%, which differs depending on the power supply impedance.

Effect of power factor improvement: power supply factor 93 to 95% (at 100% load)*3

IM

NFBPower Supply Inverter

1+ 2+

Be sure to remove the connected piece between terminals.

Wiring distance:*35 m or less.

Motor

UZDA-B

Power Factor Improvement Reactor*2

U X

Typical Connection of DC Reactor

RST

UVW

51

Circuit Pattern Input Current Waveform Input Current Spectrum Harmonics ContentNo countermeasures taken

Harmonics Order

88%

AC reactor inserted

38%

DC reactor inserted

33%

P

N

P

N

P

N

+

+

+

Typical Inverter Input Current Waveformin Each Power Supply Method (1)

1 5

1 5 7 11

1 5 7 11

52

Circuit Pattern Input Current Waveform Input Current Spectrum Harmonics Contents12-phase rectification

Harmonics Order

12%

PWM control converter

3%

P

N

P

N

+

+

1

1

Typical Inverter Input Current Waveformin Each Power Supply Method (2)

53

Chapter 4Inverter Drive Units Selection

54

From General Industrial-use to Consumer EquipmentGeneral-purpose Inverter Series

Varispeed G7

Varispeed F7

VS mini V7

VS mini J7

High-graded Function Current Vector Control (0.4 to 300 kW)

General-purpose Vector Control (0.4 to 300 kW)

Small-size Voltage Vector Control (0.1 to 7.5 kW)

Super Small-size Contactor Type (0.1 to 3.7 kW)

55

Capacity (kW) Control Method Braking Method Speed Control

200V Class 400V Class V/f

VS mini J7 Single-phase: 0.1 to 1.53-phase: 0.1 to 3.7 3-phase: 0.2 to 3.7 1:40 2 to 3

VS mini C Single-phase: 100 V 0.1 to0.75Single-phase,3-phase: 0.1 to 1.5 3-phase: 0.2 to 1.5 1:40 2 to 3

VS mini V7 Single-phase: 0.1 to 3.73-phase: 0.1 to 7.5 3-phase: 0.2 to 7.5

1:402 to 3

1

Varispeed F7 3-phase: 0.4 to 110 3-phase: 0.4 to 300

1:40 2 to 3

1:100 0.2

Varispeed G7 3-phase: 0.4 to 110 3-phase: 0.4 to 300

1:40 2 to 3 1:200 0.2

1:1000 0.02 VS-616R3 3-phase: 3.7 to 37 3-phase: 7.5 to 75 1:40 2 to 3

VS-686SS5 3-phase: 0.4 to 753-phase: 0.4 to 160

1:10 0.2

3-phase: 0.4 to 300 1:500 0.02 O

p

e

n

-

l

o

o

p

F

l

u

x

V

e

c

t

o

r

Features of Each General-purpose Inverter

P

o

w

e

r

R

e

g

e

n

e

r

a

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Model Features Output Range

VS-676H5 High-graded function type 200 V: 0.4 to 75 kW 400 V: 0.4 to 800 kW575 V: 300 to 1200 kW

VS-686HV5SHigh-voltage super energy

saving

3300 V: 132 to 1250 kW6600 V: 250 to 2500 kW

VS-686HV5 3300 V: 225 to 1800 kW6000 V: 450 to 3000 W

VS-626M5/MR5Exclusive for machine tools

spindle(high accuracy)

200 V: 2.2 / 3.7 to 22 / 30 kW400 V: 3.7 / 5.5 to 37 / 45 kW

VS-626MC5 Exclusive for machine tools spindle (simplified type)200 V: 2.2 / 3.7 to 11 / 15 kW

Sinusoidal wave PWMVS-656DC5

Harmonics: 0Power factor: 1

200 V: 15 to 75 kW400 V: 15 to 300 kW

VS-656RC5 Low cost type

200 V: 3.7 to 37 kW400 V: 3.7 to 75 kW

Exclusive-use Inverter SeriesF

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Motor Type

Motor Output

Inverter Output

Inverter Model

Peripheral units, Options

Enclosure

Check ItemWhat to Decide

Capacity Selection

Machine specifications

Operation method

Load type and characteristics

Inverter capacity selection

Inverter model selection

Motor selection

Peripheral units, options

Investment effect

Investment effect

Inverter selection

Final specifications

58

Load Characteristics Typical Load Speed Torque CharacteristicsLoad torque is constant for speed.General friction loads

ConveyorCraneWinchOther friction loads

and gravity loads

Load torque is constant regardless of speed.Output power is in proportion to speed.

T = k T: torqueP = kN P: Output

k: Proportional constantLoads of which load torque is decreased as the speed is reduced

FanBlowerPumpOther fluid loads

Load torque is in proportion to the square of speed. Output is in proportion to the

cube of speed. T = kN2P = kN3

Loads of which output becomes constant for the speed

Constant tension force winder ofcenter drive

Spindle motors of machine tools

Veneer rotary laths

Output power required by the load is constant. Load torque is in inverse proportion to speed.

T = k/NP = k

Loads of which load torque varies depending on the speedLoads having the nature between the low output load and the constant torque load

Speed torque/output characteristics between the constant torque load and constant output load

Load Torque

Load Output

SpeedTo

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Load OutputSpeedT

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Typical Load Torque Characteristics

0

1.0

1.0

2.0

Load Torque

Load Output

1.0

2.0

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Load Output

Load Torque

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59

Motor may be overheated in a low-speed area.

Since the min-1 of the external fan becomes lower in a low-speed area, the cooling capability is deteriorated. Therefore, the motor may be overheated unless the load is reduced in a low-speed area.

Motor can operate properly even in a low-speed area.

The motor is designed for inverter drives, therefore, the temperature is within the specified value even if the motor is used at a low speed.

The above characteristics show the torque that can be allowed at continuous operation. There is no difference in the torque that the motor can generate in a short time, such as at starting, between the standard motor and the constant torque motor.

Standard Motor Output Inverter Exclusive-use Motor Output

60606060

3333 20202020

0.50.50.50.5

55555555

Difference between Inverter Exclusive-use Motor and Standard Motor

Standard MotorStandard Motor Exclusive-use MotorExclusive-use Motor

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Example:1:10 Const. Torque Motor

60

Load Torque

Accel Torque

Decel Torque

Td 2piJN60td

Required Brake TorqueTB=TdTL

Required Motor Torque

TaTL

Ta 2piJN60ta

TL fVpiN

Nm

The inverter regeneration capability is a key point. The regeneration capability depends on selection of the inverter output and braking unit type.

Operation Pattern and Calculation of Load Torque

Can start?Motor starting torque must be greater than load starting torque.

Is motor temperature proper?Temperature rise must be within the specified value.

Time

Can accelerate?Motor torque exceeding the torque requiredfor acceleration (Ta+TL) must be available.

The volume of the motor output torque is a key point.Torque depends on the motor output, inverter output, control method or boost amount.

Can decelerate?Brake torque required for deceleration

must be available. Energy at deceleration can be consumed or

regenerated to the power supply.

TL

Ta

Td

TaTL

ta td

61

(a) Motor Mode

(b) Generator (Regeneration) Mode

IMCommercial

Power Mechanical Energy

Power FlowPower Flowi

S 0(Motor power factor cos0)

*1 Discharge resistor = braking resistor *2 Monitors DC voltage and turns ON the transistor when DC voltage exceeds the specified level.

The inverter built-in braking transistor or braking unit is used.

IMCommercial

Power

Mechanical EnergyKinetic EnergyPotential Energy

Power Flow

(i =0i

*1R

*2(ON)

Thermal Energy

S 0(Motor power factor cos 0)

Power Flow and Regenerative Braking

62

(1) Power supply transformer

(2) Circuit breaker or(3) Leakage breaker

(4) Contactor(6)Noise filter

(5) AC reactor

(10) Braking resistor unit

(7) DC reactor

(8) Noise filter

(9) Contactor

Peripheral Devices and Their Connections

(11) Contactor for commercial power backup

(12) Zero phase reactor

(13) Thermalrelay (14) Motor

63

No. Name Purpose and Selecting Points1 Power transformer Transformer capacity Inverter capacity 1.5

2 Circuit breaker Breaks accidental current (shortcircuit current). Rated current inverter rated current 1.5 Described in the inverter catalog.

3 Leakage breaker

Grounding protectionHigh frequency leak current protection for electric shock accident & leakage current fire.

1. Use a breaker provided with countermeasures for high frequency leakage current. 2. Increase sensitivity current.3. Decrease inverter carrier frequency.

4 ContactorSince the inverter has the contactor function, any contactor is not needed except for special cases.When a braking resistor is used, insert a contactor to make thermal trip circuit.Perform RUN/STOP at the inverter side and set the contactor to Always ON to use.

57

AC reactorDC reactor

For high frequency current suppression and improvement of power factorInstall a reactor to protect the inverter when the power supply capacity is large.

68

Noise filter orZero-phase reactor Prevent radio noise generated by inverter section

910

Braking unitBraking resistor unit Used when an electrical brake is needed (when the required braking torque exceeds 20%).

1112

Contactor for commercial power backup

Used for backup at inverter failure or when commercial power supply is used for normal operations.

13 Thermal relay Not needed when one motor is driven by one inverter. (Connected when more than two motors are used.)

How to Select Peripheral Devices

64

Chapter 5Inverter Functions and Advantages

65

No. Advantage Technical Details Main Precautions

1

Can control speeds of the specified constant-speed type motors.

Number of revolutions changes when squirrel-cage-type motor terminal voltage and frequency are changed.

Since a standard motor has temperature rise that becomes greater at a low speed, torque must be reduced according to frequency.

2

Soft start/stop enabled. Accel/decel time can be set freely from a low speed.(0.01 to 6000 seconds).

Set proper accel/decel time after performing load operation.

3

Highly frequent start/stop enabled.

Little motor heat generation since smooth accel/decel is enabled with little current.

Motor or inverter capacity frame must be increased depending on the accel/decel capacity. Check the accel/decel time and load J.

4

FWD/REV run enabled without main circuit contactor.

Because of phase rotation changes by transistor, there are no moving parts like conventional contactors so that interlock operation can be assured.

When applying the inverter to an elevating unit, use a motor with a brake to hold mechanically for stand still.

Advantages of Inverter Applications (1)

Cushion Start

t

f

FWD

Run

REV

Run

Cushion Stop

Inverter

RUN Command

FWD

Run

REV

Run

t

f

66

No. Advantage Technical Details Main Precautions

5

Can apply an electrical brake. Since mechanical energy is converted into electrical energy and absorbed in the inverter at decel, the motor can auto-matically provide braking force.DC current is applied to the motor around zero-speed so that it becomes dynamic braking, to completely stop the motor.

Braking force is approx. 20% when only the inverter is used. Attaching a braking resistor (optional) externally can increase the braking force.Pay attention to the capacity of the resistor.

6

Can control speeds of the motor under adverse atmosphere.

Since the inverter drives squirrel-cage motors, it can be used easily for explosionproof, waterproof, outdoor or special types of motors.

An explosionproof motor in combination with an inverter is subject to explosionproof certification.

7

High-speed rotation enabled. Commercial power supply can provide up to 3600 min-1 (2-pole at 60Hz) or 3000 min-1 (2-pole, at 50Hz). A general-purpose inverter can increase frequency up to 400 Hz (12000 min-1) while a high-frequency inverter can increase it up to 3000 Hz (180000 min-1).

The speed of a general-purpose motor cannot be increased by simply increasing the frequency. (It can be applied without being changed if frequency is approx. 120 Hz.)Mechanical strength and dynamic balance must be examined. 60Hz 120Hz 400Hz

Electrical Braking

Advantages of Inverter Applications (2)

f

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No. Advantage Technical Details Main Precautions

8

The speeds of more than one motor can be controlled by one inverter.

The inverter is a power supply unit to the motor, therefore, as many motors as the capacity allows can be connected.These motors do not have to be the same capacity.

The number of motor revolutions differs depending on each motor characteristics or load ratio even at the same frequency.(Among general-purpose motors, speed deviation of 2 to 3% can be considered.)Synchronous motors have the same number of revolutions.

9

Power supply capacity can be small when the motor is started up.

Large current (5 or 6 times larger than the motor rating) does not flow as with a commercial power supply start.Current can be limited to at most 100 to 150% by low-frequency start.

Transformer capacity (kVA)= 1.5 inverter output capacity

10Number of revolutions becomes constant regardless of power supply frequency.

Output freq. can be set regardless of power supply freq. 50/60Hz.

Inverter

Advantages of Inverter Applications (3)

IM

IM

IM

68

Inverter Output Voltage

Inverter Output Current

Inverter Input Current

150%

150%100% Current

100% Current

100% Voltage (100% Speed)

t

Motor and Power Supply Currentin Inverter Drives

t

t0

69

Energy Saving for General Industrial Machines & Systems

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(1)Energy Saving for Mechanical Systems by Means of Variable Speed Drive of Motors

(2)High Efficiency Motors

(3)Change to High Efficiency Drive for Existing Variable Speed Drive

(4)Regeneration of Braking (Kinetic)Energy

(5)Others

A . Variable Torque LoadB . Constant Torque LoadC . Constant Power Load

A . High Efficiency Induction Motor B . IPM(Interior Permanent Magnet Motor)

A . Primary Voltage Control of Induction MotorB . Secondary Resistor Control of Wound Rotor Induction MotorC . VS-Motor (Eddy Current Coupling Motor)D . Variable Frequency Drive of Induction MotorE . Variable Frequency Drive of IPM

A . Regenerative ConverterB . Drive Regenerated Energy To Another Inv. Drive

A . ON-OFF Control for Mechanical SystemsB . Inverter Energy Saving (Voltage) Control Method

70

Applied Load Concept of Energy-saving Fans Pumps Blowers (Any Variable Torque Load)

Replace with a more efficient motor. Reduce a redundancy of the facility for the actual loads. Abate the head loss at valves or dampers.

(2) (1) (1)

Extruders Conveyors, etc. (Any Constant Torque Load)

Change to more efficient drives. Replace the primary voltage control, secondary resistance control, eddy-current coupling (VS motors) with a more efficient control method(Frequency Control).

(3)

Cranes Elevators, etc.

Collect the regenerative energy at lowering by using the inverter power supply regenerative function.

(4)

Rewinders Collect the regenerative energy of the rewinders. Replace with a more efficient motor. (4) (2)

General Machines Reduce the starting energy. (Use the inverter as a starter to stop the operations positively whenever the load ratio is low.)

(5)a

Optimum Energy-saving Plan for Facility

71

AN

Hd1.0

0 0.5 1.0 ( p.u.)Air volume (Q)

R

Hi

( p.u.)

Air Volume and Wind Pressure Characteristics of Fan

H1.03N0.56NQ0.59QRQ

Rated air volume: 250m3/secRated wind pressure: 433mmAqFan efficiency at rated air volume: 0.7Fan efficiency at 50% air volume: 0.6

Ad

Ai

R50

N50Q50H0

72

Energy saving Effect in the Fan Application In the case of damper control

The wind pressure in 50% air volume is Hd = 1.03 + 0.56 0.5 - 0.59 0.52 = 1.16

The power becomesm = 0.9 is the motor efficiency

In the case of inverter controlThe wind pressure in 50% air volume is Hi = 0.52 = 0.25

The power becomesi = 0.95 is the inverter efficiency

The electric-power saving quantityPS = PD Pi = 15.3kWOn the assumption of electric power unit price: \15/kWh and annual continuous running:

8000hours,We can save the electric charge as follows. 15.3 15 8000 = \ 1,836,000

19.0kW=4332500.90.661201.160.5

=6120QH

=Pmf

D

3.7kW=4332500.950.90.761200.250.5

=6120QH

=Piimf

73

Flow Rate and Head Characteristics of Pump

Squeeze volume

Low speed

1.5

HB

1

Hi0.5

0 0.5 1

Flow rate (P.U)

H

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P

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U

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R50

R

NR0

N50

74

Energy saving Effect in the Pump Application In the case of valve control

The head in 50% flow rate is HB = 1.25 0.25 0.52 = 1.188

The power becomesm = 0.9 is the motor efficiency

In the case of inverter controlThe head in 50% flow rate is Hi = 0.7 0.1 0.52 = 0.725

The power becomesi = 0.95 is the inverter efficiency

The electric-power saving quantityPS = PB Pi = 15.2kWOn the assumption of electric power unit price: \15/kWh and annual continuous running:

8000hours,We can save the electric charge as follows. 15. 2 15 8000 = \ 1,824,000

28.9kW=2560.90.566.121.1880.5

=6.12QH

=Pmp

B

13.7kW=2560.950.90.766.120.7250.5

=6.12QH

=Piimp

75

Outline of Software Functions (1)Function Name Function Name Function Name Function Name ApplicationsApplicationsApplicationsApplications PurposePurposePurposePurpose DescriptionDescriptionDescriptionDescription

MultiMultiMultiMulti----step Speed step Speed step Speed step Speed

OperationOperationOperationOperation

Feeders,Feeders,Feeders,Feeders, etcetcetcetc.... Schedule operation Schedule operation Schedule operation Schedule operation

at specified speedat specified speedat specified speedat specified speed

By combining signals, operation is performed at frequency stored By combining signals, operation is performed at frequency stored By combining signals, operation is performed at frequency stored By combining signals, operation is performed at frequency stored

internally (up to 9internally (up to 9internally (up to 9internally (up to 9----step speeds). Connection with the sequencer is easy; step speeds). Connection with the sequencer is easy; step speeds). Connection with the sequencer is easy; step speeds). Connection with the sequencer is easy;

simplified positioning by using limit switch is also possible. simplified positioning by using limit switch is also possible. simplified positioning by using limit switch is also possible. simplified positioning by using limit switch is also possible.

Accel/decel Changing Accel/decel Changing Accel/decel Changing Accel/decel Changing

OperationOperationOperationOperation

Automatic panel Automatic panel Automatic panel Automatic panel

feeders, etc.feeders, etc.feeders, etc.feeders, etc.

Changing external Changing external Changing external Changing external

signal of accel/decel signal of accel/decel signal of accel/decel signal of accel/decel

timetimetimetime

Using an external signal can change the accel/decel rate. This function Using an external signal can change the accel/decel rate. This function Using an external signal can change the accel/decel rate. This function Using an external signal can change the accel/decel rate. This function

is effective when two motors are driven alternately by one inverter or is effective when two motors are driven alternately by one inverter or is effective when two motors are driven alternately by one inverter or is effective when two motors are driven alternately by one inverter or

when smooth accel/decel is needed only in the highwhen smooth accel/decel is needed only in the highwhen smooth accel/decel is needed only in the highwhen smooth accel/decel is needed only in the high----speed area.speed area.speed area.speed area.

SSSS----curve Time curve Time curve Time curve Time

CharacteristicsCharacteristicsCharacteristicsCharacteristics

feeders such as feeders such as feeders such as feeders such as

conveyors, carts, conveyors, carts, conveyors, carts, conveyors, carts,

etc.etc.etc.etc.

Prevention of Prevention of Prevention of Prevention of

start/stop shockstart/stop shockstart/stop shockstart/stop shock

Smooth movement can be achieved by setting SSmooth movement can be achieved by setting SSmooth movement can be achieved by setting SSmooth movement can be achieved by setting S----curve delay when curve delay when curve delay when curve delay when

accel/decel starts or finishes.accel/decel starts or finishes.accel/decel starts or finishes.accel/decel starts or finishes.

FrequencyFrequencyFrequencyFrequency Upper/lower Upper/lower Upper/lower Upper/lower

Limit OperationLimit OperationLimit OperationLimit Operation

PumpsPumpsPumpsPumps

BlowersBlowersBlowersBlowers

Limit of motor Limit of motor Limit of motor Limit of motor

revolutionsrevolutionsrevolutionsrevolutions

Frequency reference upper/lower value, bias and gain can be set Frequency reference upper/lower value, bias and gain can be set Frequency reference upper/lower value, bias and gain can be set Frequency reference upper/lower value, bias and gain can be set

individually without adding any peripheral devices.individually without adding any peripheral devices.individually without adding any peripheral devices.individually without adding any peripheral devices.

Specified Frequency Specified Frequency Specified Frequency Specified Frequency

Setting Prohibition Setting Prohibition Setting Prohibition Setting Prohibition

(Frequency Jump Control)(Frequency Jump Control)(Frequency Jump Control)(Frequency Jump Control)

General machinesGeneral machinesGeneral machinesGeneral machines Prevention of Prevention of Prevention of Prevention of

machine system machine system machine system machine system

vibrationvibrationvibrationvibration

In order to prevent vibration of the machine system, the oscillation point In order to prevent vibration of the machine system, the oscillation point In order to prevent vibration of the machine system, the oscillation point In order to prevent vibration of the machine system, the oscillation point

is avoided automatically during constantis avoided automatically during constantis avoided automatically during constantis avoided automatically during constant----speed operation. This function speed operation. This function speed operation. This function speed operation. This function

can also be used for dead zone control.can also be used for dead zone control.can also be used for dead zone control.can also be used for dead zone control.

DWELL FunctionDWELL FunctionDWELL FunctionDWELL Function HeavyHeavyHeavyHeavy----inertia loads inertia loads inertia loads inertia loads

such as centrifugal such as centrifugal such as centrifugal such as centrifugal

separators etc.separators etc.separators etc.separators etc.

Smooth accel/decel Smooth accel/decel Smooth accel/decel Smooth accel/decel

of heavyof heavyof heavyof heavy----inertia inertia inertia inertia

loadsloadsloadsloads

Prevents the motor from stalling by holding output frequency temporarily Prevents the motor from stalling by holding output frequency temporarily Prevents the motor from stalling by holding output frequency temporarily Prevents the motor from stalling by holding output frequency temporarily

during accel/decel. during accel/decel. during accel/decel. during accel/decel.

Speed SearchSpeed SearchSpeed SearchSpeed Search Inertia load drives Inertia load drives Inertia load drives Inertia load drives

such as blowers, such as blowers, such as blowers, such as blowers,

winders winders winders winders

Starting of coasting Starting of coasting Starting of coasting Starting of coasting

motormotormotormotor

PerformsPerformsPerformsPerforms pullpullpullpull----inininin operationoperationoperationoperation automaticallyautomaticallyautomaticallyautomatically intointointointo thethethethe setsetsetset frequencyfrequencyfrequencyfrequency withoutwithoutwithoutwithout

stoppingstoppingstoppingstopping thethethethe coastingcoastingcoastingcoasting motormotormotormotor.... MotorMotorMotorMotor speedspeedspeedspeed detectordetectordetectordetector isisisis notnotnotnot neededneededneededneeded....

Compensation for Compensation for Compensation for Compensation for

Momentary Power LossMomentary Power LossMomentary Power LossMomentary Power Loss

General machinesGeneral machinesGeneral machinesGeneral machines Continuing operation Continuing operation Continuing operation Continuing operation

at a momentary at a momentary at a momentary at a momentary

power losspower losspower losspower loss

Restart the motor automatically after recovery from a momentary power Restart the motor automatically after recovery from a momentary power Restart the motor automatically after recovery from a momentary power Restart the motor automatically after recovery from a momentary power

loss by using the remaining control power supply to continue the motor loss by using the remaining control power supply to continue the motor loss by using the remaining control power supply to continue the motor loss by using the remaining control power supply to continue the motor

operations. operations. operations. operations.

Fault RetryFault RetryFault RetryFault Retry AirAirAirAir----conditioning,conditioning,conditioning,conditioning,

etcetcetcetc....

Improvement of Improvement of Improvement of Improvement of

operation reliabilityoperation reliabilityoperation reliabilityoperation reliability

Resets the fault automatically after the inverter detects a fault and Resets the fault automatically after the inverter detects a fault and Resets the fault automatically after the inverter detects a fault and Resets the fault automatically after the inverter detects a fault and

performs selfperforms selfperforms selfperforms self----analysis and restarts the operation without stopping the analysis and restarts the operation without stopping the analysis and restarts the operation without stopping the analysis and restarts the operation without stopping the

motor. Up to 10 retry operations may be selected.motor. Up to 10 retry operations may be selected.motor. Up to 10 retry operations may be selected.motor. Up to 10 retry operations may be selected.

76

Outline of Software Functions (2)Function Name Function Name Function Name Function Name ApplicationsApplicationsApplicationsApplications PurposePurposePurposePurpose DescriptionDescriptionDescriptionDescription

Carrier Frequency SettingCarrier Frequency SettingCarrier Frequency SettingCarrier Frequency Setting GeneralGeneralGeneralGeneral machinesmachinesmachinesmachines NoiseNoiseNoiseNoise reductionreductionreductionreduction SetsSetsSetsSets thethethethe inverterinverterinverterinverter carriercarriercarriercarrier frequencyfrequencyfrequencyfrequency totototo anyanyanyany arbitraryarbitraryarbitraryarbitrary valuevaluevaluevalue totototo reducereducereducereduce

noisenoisenoisenoise oscillationoscillationoscillationoscillation fromfromfromfrom thethethethe motormotormotormotor andandandand machinemachinemachinemachine systemsystemsystemsystem.... ThisThisThisThis functionfunctionfunctionfunction isisisis

alsoalsoalsoalso effectiveeffectiveeffectiveeffective forforforfor reducingreducingreducingreducing noisenoisenoisenoise....

Load Speed DisplayLoad Speed DisplayLoad Speed DisplayLoad Speed Display General machinesGeneral machinesGeneral machinesGeneral machines Improvement of Improvement of Improvement of Improvement of

monitor functionmonitor functionmonitor functionmonitor function

CanCanCanCan displaydisplaydisplaydisplay thethethethe motormotormotormotor speedspeedspeedspeed (min(min(min(min

-

--

-1

11

1

),),),), loadloadloadload machinemachinemachinemachine rotatingrotatingrotatingrotating speedspeedspeedspeed (min(min(min(min

-

--

-1

11

1

))))

orororor linelinelineline speedspeedspeedspeed (m/min)(m/min)(m/min)(m/min)....

Pulse Train InputPulse Train InputPulse Train InputPulse Train Input General machinesGeneral machinesGeneral machinesGeneral machines Improvement of Improvement of Improvement of Improvement of

operabilityoperabilityoperabilityoperability

In addition to the function as frequency reference, PID aimed value and In addition to the function as frequency reference, PID aimed value and In addition to the function as frequency reference, PID aimed value and In addition to the function as frequency reference, PID aimed value and

PID feedback value at PID control can be input as a pulse train.PID feedback value at PID control can be input as a pulse train.PID feedback value at PID control can be input as a pulse train.PID feedback value at PID control can be input as a pulse train.

Pulse Train OutputPulse Train OutputPulse Train OutputPulse Train Output General machinesGeneral machinesGeneral machinesGeneral machines Improvement of Improvement of Improvement of Improvement of

monitoring monitoring monitoring monitoring

performanceperformanceperformanceperformance

Frequency reference, output frequency, motor speed, output frequency Frequency reference, output frequency, motor speed, output frequency Frequency reference, output frequency, motor speed, output frequency Frequency reference, output frequency, motor speed, output frequency

after softafter softafter softafter soft----start, PID feedback amount and PID input value can be output start, PID feedback amount and PID input value can be output start, PID feedback amount and PID input value can be output start, PID feedback amount and PID input value can be output

in pulses.in pulses.in pulses.in pulses.

Stopping Method Stopping Method Stopping Method Stopping Method

Selection Selection Selection Selection

GeneralGeneralGeneralGeneral machinesmachinesmachinesmachines Stopping method Stopping method Stopping method Stopping method

suitable for the suitable for the suitable for the suitable for the

machine machine machine machine

characteristicscharacteristicscharacteristicscharacteristics

Selects deceleration to a stop, coasting to a stop or DC injection Selects deceleration to a stop, coasting to a stop or DC injection Selects deceleration to a stop, coasting to a stop or DC injection Selects deceleration to a stop, coasting to a stop or DC injection

braking stop according to the braking torque or machine inertia. braking stop according to the braking torque or machine inertia. braking stop according to the braking torque or machine inertia. braking stop according to the braking torque or machine inertia.

3333----wire Sequencewire Sequencewire Sequencewire Sequence General machinesGeneral machinesGeneral machinesGeneral machines SimpleSimpleSimpleSimple configurationconfigurationconfigurationconfiguration

ofofofof controlcontrolcontrolcontrol circuitcircuitcircuitcircuit

Operation is enabled using automaticOperation is enabled using automaticOperation is enabled using automaticOperation is enabled using automatic----recoveryrecoveryrecoveryrecovery----type pushbutton switch.type pushbutton switch.type pushbutton switch.type pushbutton switch.

Frequency Hold OperationFrequency Hold OperationFrequency Hold OperationFrequency Hold Operation General machinesGeneral machinesGeneral machinesGeneral machines Improvement of Improvement of Improvement of Improvement of

operabilityoperabilityoperabilityoperability

Holds frequency increase/decrease temporarily during acceleration or Holds frequency increase/decrease temporarily during acceleration or Holds frequency increase/decrease temporarily during acceleration or Holds frequency increase/decrease temporarily during acceleration or

deceleration. deceleration. deceleration. deceleration.

UP/DOWN OperationUP/DOWN OperationUP/DOWN OperationUP/DOWN Operation General machinesGeneral machinesGeneral machinesGeneral machines Improvement of Improvement of Improvement of Improvement of

operabilityoperabilityoperabilityoperability

Speed setting is enabled remotely by ON/OFF operation. Speed setting is enabled remotely by ON/OFF operation. Speed setting is enabled remotely by ON/OFF operation. Speed setting is enabled remotely by ON/OFF operation.

Frequency DetectionFrequency DetectionFrequency DetectionFrequency Detection General machinesGeneral machinesGeneral machinesGeneral machines Frequency detection Frequency detection Frequency detection Frequency detection

to be used for to be used for to be used for to be used for

interlockinterlockinterlockinterlock

Specifies the set value of output frequency, and outputs to the multiSpecifies the set value of output frequency, and outputs to the multiSpecifies the set value of output frequency, and outputs to the multiSpecifies the set value of output frequency, and outputs to the multi----

function output terminal when frequency exceeds the range or becomes function output terminal when frequency exceeds the range or becomes function output terminal when frequency exceeds the range or becomes function output terminal when frequency exceeds the range or becomes

short.short.short.short.

Overtorque Detection and Overtorque Detection and Overtorque Detection and Overtorque Detection and

Undertorque DetectionUndertorque DetectionUndertorque DetectionUndertorque Detection

MachineMachineMachineMachine toolstoolstoolstools

Blowers,Blowers,Blowers,Blowers, cutters,cutters,cutters,cutters,

extrudersextrudersextrudersextruders

Machine protection, Machine protection, Machine protection, Machine protection,

improvement of improvement of improvement of improvement of

reliability for reliability for reliability for reliability for

continuous operationcontinuous operationcontinuous operationcontinuous operation

"Closed" when motor generating torque exceeds the overtorque "Closed" when motor generating torque exceeds the overtorque "Closed" when motor generating torque exceeds the overtorque "Closed" when motor generating torque exceeds the overtorque

detection level. Can be used as an interlock signal for machine detection level. Can be used as an interlock signal for machine detection level. Can be used as an interlock signal for machine detection level. Can be used as an interlock signal for machine

protection such as cutting loss or overload detection of machine tools.protection such as cutting loss or overload detection of machine tools.protection such as cutting loss or overload detection of machine tools.protection such as cutting loss or overload detection of machine tools.

77

Outline of Software Functions (3)Function Name Function Name Function Name Function Name ApplicationsApplicationsApplicationsApplications PurposePurposePurposePurpose DescriptionDescriptionDescriptionDescription

Stall PreventionStall PreventionStall PreventionStall Prevention General General General General

machinesmachinesmachinesmachines

Machine protection, Machine protection, Machine protection, Machine protection,

improvement of improvement of improvement of improvement of

reliability for reliability for reliability for reliability for

continuous operation continuous operation continuous operation continuous operation

Interrupts accel/decel when frequency reaches each set value during Interrupts accel/decel when frequency reaches each set value during Interrupts accel/decel when frequency reaches each set value during Interrupts accel/decel when frequency reaches each set value during

acceleration, deceleration or running, and continues operation when it acceleration, deceleration or running, and continues operation when it acceleration, deceleration or running, and continues operation when it acceleration, deceleration or running, and continues operation when it

becomes lower than the set value. becomes lower than the set value. becomes lower than the set value. becomes lower than the set value.

Electronic Overload Electronic Overload Electronic Overload Electronic Overload

Thermal RelayThermal RelayThermal RelayThermal Relay

General General General General

machinesmachinesmachinesmachines

Detection of motor Detection of motor Detection of motor Detection of motor

overloadoverloadoverloadoverload

Set the motor rated current value and select the allowable load Set the motor rated current value and select the allowable load Set the motor rated current value and select the allowable load Set the motor rated current value and select the allowable load

characteristics for each motor type, and the electronic overload thermal characteristics for each motor type, and the electronic overload thermal characteristics for each motor type, and the electronic overload thermal characteristics for each motor type, and the electronic overload thermal

relay performs overload protection.relay performs overload protection.relay performs overload protection.relay performs overload protection.

Torque Limit (Droop Torque Limit (Droop Torque Limit (Droop Torque Limit (Droop

Characteristics Selection)Characteristics Selection)Characteristics Selection)Characteristics Selection)

Pumps,blowers,Pumps,blowers,Pumps,blowers,Pumps,blowers,

extruders,extruders,extruders,extruders, etcetcetcetc....

Machine protectionMachine protectionMachine protectionMachine protection

Improvement of Improvement of Improvement of Improvement of

reliability for reliability for reliability for reliability for

continuous operationcontinuous operationcontinuous operationcontinuous operation

Torque limitTorque limitTorque limitTorque limit

AdjustsAdjustsAdjustsAdjusts outputoutputoutputoutput frequencyfrequencyfrequencyfrequency accordingaccordingaccordingaccording totototo thethethethe loadloadloadload statusstatusstatusstatus whenwhenwhenwhen thethethethe motormotormotormotor

generatinggeneratinggeneratinggenerating torquetorquetorquetorque reachesreachesreachesreaches aaaa certaincertaincertaincertain levellevellevellevel....

OptimumOptimumOptimumOptimum forforforfor tiptiptiptip----lesslesslessless operationoperationoperationoperation forforforfor pumpspumpspumpspumps orororor blowersblowersblowersblowers....

EnergyEnergyEnergyEnergy----saving Controlsaving Controlsaving Controlsaving Control General General General General

machinesmachinesmachinesmachines

Automatic operation Automatic operation Automatic operation Automatic operation

with maximum with maximum with maximum with maximum

efficiencyefficiencyefficiencyefficiency

Supplies sufficient voltage for the motor to reach maximum efficiency Supplies sufficient voltage for the motor to reach maximum efficiency Supplies sufficient voltage for the motor to reach maximum efficiency Supplies sufficient voltage for the motor to reach maximum efficiency

according to the load or rotating speed.according to the load or rotating speed.according to the load or rotating speed.according to the load or rotating speed.

PID ControlPID ControlPID ControlPID Control Pumps,Pumps,Pumps,Pumps,

airairairair----conditioning,conditioning,conditioning,conditioning,

etcetcetcetc....

Automatic process Automatic process Automatic process Automatic process

controlcontrolcontrolcontrol

CalculatesCalculatesCalculatesCalculates thethethethe PIDPIDPIDPID inininin thethethethe inverterinverterinverterinverter andandandand usesusesusesuses thethethethe resultresultresultresult ofofofof thethethethe calculationcalculationcalculationcalculation

asasasas itsitsitsits ownownownown frequencyfrequencyfrequencyfrequency referencereferencereferencereference totototo performperformperformperform constantconstantconstantconstant controlcontrolcontrolcontrol ofofofof pressure,pressure,pressure,pressure,

flowflowflowflow rate,rate,rate,rate, windwindwindwind amount,amount,amount,amount, etcetcetcetc....

Droop ControlDroop ControlDroop ControlDroop Control Conveyors of Conveyors of Conveyors of Conveyors of

distributed drivesdistributed drivesdistributed drivesdistributed drives

MultiMultiMultiMulti----drive drive drive drive

motorsmotorsmotorsmotors

Proper distribution of Proper distribution of Proper distribution of Proper distribution of

loadloadloadload

SetsSetsSetsSets motormotormotormotor speedspeedspeedspeed regulationregulationregulationregulation totototo anananan arbitraryarbitraryarbitraryarbitrary valuevaluevaluevalue....

MakingMakingMakingMaking highhighhighhigh----resistanceresistanceresistanceresistance characteristicscharacteristicscharacteristicscharacteristics distributesdistributesdistributesdistributes thethethethe loadsloadsloadsloads ofofofof severalseveralseveralseveral

motorsmotorsmotorsmotors properlyproperlyproperlyproperly....

Zero Servo FunctionZero Servo FunctionZero Servo FunctionZero Servo Function Elevators,Elevators,Elevators,Elevators, cartscartscartscarts ZeroZeroZeroZero----speed stop to speed stop to speed stop to speed stop to

lock the motorlock the motorlock the motorlock the motor

HoldsHoldsHoldsHolds aaaa motormotormotormotor inininin thethethethe lockedlockedlockedlocked statusstatusstatusstatus atatatat zerozerozerozero speedspeedspeedspeed whetherwhetherwhetherwhether externalexternalexternalexternal forceforceforceforce

isisisis appliedappliedappliedapplied inininin thethethethe forwardforwardforwardforward orororor reversereversereversereverse directiondirectiondirectiondirection....

78

Similar MachinesAir-conditioning fans for buildingsFans for cooling towerDust collection blowersFans for boilersHeat treating furnace blowers

Application for Dust Collection BlowersFunctions AvailableChanging of commercial power supply and inverter operationsRestart from coasting statusEnergy-saving control mode at light loadFault retry

Inverter

BlowerDust CollectorDamper

Motor MCMCMCB

MC

79

Application for Chemical Feeding Pumps

Inverter

Raw Water

PumpFlow Rate Detection

Adjuster

Motor

Chemical

Speed Reference (4 to 20 mA)

MCB

Similar MachinesChemical feeding pumpsCool/warm water circulation pumps Water supply/ discharge pumps Hydraulic pumpsSubmersible pumps

Functions AvailableEnergy-saving control mode at low speed PID control4-20mA reference by instrumentation Minimum speed setting

80

Conveyor Follow-up Operation

HopperFeeder

ConveyorGeared Motor

Geared Motor MCB

MCB

PG Pulse Encoder

InverterInverter

Power Supply

Main Speed Setting

Pulse Train Input

Power Supply

Similar MachinesRaw material supply conveyors Shuttle conveyorsChain conveyorsSteel pipe feeding conveyors

Functions AvailableImprovement of constant position stop accuracy Increasing the starting torque Smooth accel/decelChanging accel/decel timeSimultaneous control of several motors by one inverter

81

Example for Crane Exclusive-use Software ( V/f Control )

IOUT : Inverter Output Frequency (Actual)FRF : Brake Release Frequency (Set)BF : Brake Operation Stand By Frequency (Set)BT : Brake Operation Delay Time (Set)IF : Brake Release Current (Set)

BDT : Brake Operation Delay Time (Actual)FHF : Brake Make Up Frequency (Set)HF : Slip Down Prevention Frequency (Set)HT : Slip Down Prevention Time (Set)

Closed

BF

FRF

Closed

Closed

Released

BT

BDT

IOUTIF

HT

BDT

HF

FTF

Speed Reference

(FWD) Run Command (F)

Output Frequency

Brake Release Command BR

Brake Release Check BX

Brake Operation Closed

Released

Released

Released

82

()

M B M C

9 10

R(L1)

S(L2)

T(L3)

1

3

*

*

2k

2k

2k

P P

P

S1

S2

S3

S4

S5

S6

S7

S8

S9

S10

S11

S12

SC

(0V)

E(G )

PR

A1

A2

A3

AC

0V

C 4

P4

C 3

P3

P2

P1

PC

48V50m A

AC250V1A

DC 30V1A

FLT

BR

( )

AC250V1A

DC 30V1A

M A

M B

M C

M 1

M 2

1

2

AF

AC

AM

(3)

U(T1)

V(T2)

W (T3)

1

2

1 2

()

Varispeed

1

(a)

2

Connection Diagram for CranesEmergency Main Switch

MS Master Switch

MC Main Circuit Conductor

F FWD Run Command

R REV Run Command

B Brake Conductor

BBX Brake Applying Command

BX Brake Release Check

: Twisted pair-shielded cable

Braking Resistor Unit (Optional)

Varispeed G7

Class 3 Grounding (100 or more)

Multifunction Terminal

External Fault

Fault Reset

Multi-speed Ref 1Multi-speed Ref 2

Multi-speed Ref 3Not Used

Sequence CommonInsulated from (0V) terminal.

Shielded Sheath Cable Connection Terminal

Brake Release Command (Brake released at closed)250 VAC, 1 A or less30 VDC, 1 A or less

Fault Contact Output250 VAC, 1 A or less30 VDC, 1 A or less

Multifunction PHC Output48 V, 50 mA or less

ONOFF

R

E

V

R

u

n

S

t

o

p

F

W

D

R

u

n

Brake Applying CommandBrake Self-holding

M1 M2

Brake Release Check

Accel/decel Time Selection 1

Emergency Stop (NO Contact)

External Baseblock *

* External baseblock signal baseblock at closed.

*

FWD Run/StopREV Run/Stop

Analog Monitor 2

Analog Monitor 1

Multifunction Analog Output

Note *

83

Spindle

X-axisCore Clamper

Z-axis

Motor

Similar Machines

PolishersGrindersSmall lathesPlano miller feedersMilling machinesDrilling machinesPresses

Functions AvailableBlade cutting loss prevention Wide range of constant output powerControl by digital inputs Vibration control

Principle Diagram of Lathe

84

Elevator Application

Sheave

Vector Control PWM Inverter

Braking Resistor, Braking Transistor (Externally Mounted)Inverter Section Converter Section

Induction Motor

C

u

r

r

e

n

t

D

e

t

e

c

t

i

o

n

AC Reactor

Cage Calling Signal

Entrance Calling Signal

Speed FeedbackVector Control

Run Operation Signal

L

o

a

d

D

e

t

e

c

t

o

r

C

a

g

e

B

a

l

a

n

c

e

W

e

i

g

h

t

Elevator Controller

Operation Control

Torque Ref. Generated

Position Calculation Speed Ref. Generated

Speed/Position DetectionLoad Detection

3-phase AC Power Supply

PWM Control

Status Signal Fault Signal

AC Current Controller

Torque Compensation Speed Controller

Speed Ref.

Speed Reducer

Similar MachinesEscalatorsRope waysCable carsElectric railcarsElectric automobiles

Functions AvailableImprovement of cage landing frequencySoft-start with S-curve function Slip prevention at start/stopBattery operation at a power failure

85

Chapter 6Inverter Drives Precautions

86

(a) Vertical (b) Horizontal (b) Side by Side

Installation

87

(a) Right and Left Space (b) Top and Bottom Space

MountingAmbient temperature:

-10 to 40

Ambient humidity:

90% RH or less

Vibration:

Less than 20 Hz

9.8 m/s2 or less

20 to 50 Hz

2 m/s2 or less

50mm or more

30mm or more 30mm or more50mm or more

120mm or more

120mm or moreAir

Air

88

Bottom Cover Mounting Screw

Remove the unit top and bottom covers for the 20HP (15 kW) or less models (200-V class, 400-V class).

()

Totally-enclosed Type Control Panel Installation

CoolingFin

Totally-enclosed Type Control Panel

Top CoverIn-panel Air Temperature at Top: 10 to +55Cooling Fin

Open chassis Type Inverter

Bottom CoverInverter Intake Air Temperature : 10 to +45

Ambient Temperature 40Bottom Cover

Top Cover(One-touch)Ambient temperature:

+14 to 113F

(-10 to 45 ) Ambient humidity:

90% RH or less

Vibration:

Less than 20 Hz

9.8 m/s2 or less

20 to 50 Hz

2 m/s2 or less

89

(a) Best Grounding

Inverter(1)

Inverter (2)

Inverter(3)

E E E

(b) Good Grounding

(c) Wrong Grounding

Inverter(1)

Inverter(2)

Inverter(3)

E E E

Inverter(1)

Inverter(2)

Inverter(3)

E E E

(A loop must not be made.)

Multiple Inverters Grounding

90

0 3 6 20 60

Continuous

100

807060

50

Frequency (Hz)

25%ED (or 15 minutes)40%ED (or 20 minutes)

60%ED (or 40 minutes)

90

Allowable Load Characteristics of Standard Motors

RunRun

StopR

T

ED 100R

T

T

o

r

q

u

e

(

%

)

91

Chapter 7 Harmonics, Noise & Surge Voltage

92

Noise Harmonics

Frequency Band High frequency (10 kHz or more) 40th to 50th harmonics (up to several kHz)

Main Source Inverter section Converter section Transmission Path

Electric wire (conduction) Space (radiation) Induction (electrostatic,

electromagnetic

Electric wire

Influence Distance, wiring distance Line impedance Generating Amount

Voltage variation ratio Switching frequency

Current capacity

Failure Sensor malfunction Radio noise

Overheat of capacitor for P.F improvement Overheat of generator

Corrective Actions Change the wiring route. Install a noise filter. Install INV. in a screened

box

Install a reactor. 12-phase rectification Sinusoidal wave power regeneration

converter

Difference between Harmonics and Noise

93

C

o

m

m

e

r

c

i

a

l

P

o

w

e

r

+S

m

o

o

t

h

i

n

g

C

a

p

a

c

i

t

o

r

Converter Section

Motor

Bridge Rectifier

Harmonics Current Generated by Rectifier Circuit

Noise Generated by High-speed Switching

Harmonics and Noise Sources

Inverter Section

94

Fundamental Wave Current(at 50 or 60 Hz)

Harmonics Current(Example of 5th Level Harmonics)

(Amplitude Ratio: 0.3)

Distorted Wave Current

Fundamental Wave + Harmonics = Distorted Wave AC(Harmonics Superimposed on Fundamental Wave)

0 pipi2

A

B

A+B

95

EDC

Converter

er es et

er-s er-t es-t es-r et-r et-s

Power Supply Phase Voltage

Ver-s

er

es

et

r

s

t

EDC (Without Capacitor)

Power Supply Line Voltage

Power Supply Current Waveform

Phase R ir

Phase Sis

Phase it

Generation of Harmonics Current

96

(Harmonics Current Suppression)(a) AC Reactor

+

Inverter

Motor

AC Reactor

C

o

m

m

e

r

c

i

a

l

P

o

w

e

r

(b) DC Reactor

+

Inverter

Motor

DC Reactor

CommercialPower

Reactor Connection

97

Radio

Machine

Inverter

Power Supply Transformer

Amplifier

Conductive noise : Noise that flows out through the power supply line or grounding line Induction (electromagnetic, electrostatic)

: Noise transmitted by electromagnetic or electrostatic integration for the signal lines provided for the inverter main circuit wiring

Radiation : Noise radiated into the air through the inverter, motor unit, main circuit wiringthat work as antenna.

Noise Transmission Paths

Electronic Device

Sensor

98

Shielding (Steel) Plate Power LineSignal Line

Inverter M

Metallic Raceway Metallic Raceway

Wiring Separation by Rack or Duct

Induction Noise Suppression and Metallic Raceway

99

(a) Capacitive Filter (b) Inductive Filter (Zero-phase Reactor)

Power Supply

P

o

w

e

r

S

u

p

p

l

y

(c) LC Filter

Conductive Noise Suppression

InverterInverter

Power Supply

Inverter

100

InverterInverter

0V(Common)

0V(Common)

Junction Terminal

Inverter Noise Prevention (Shielded Sheath Wire)

101

Motor

Progress and Reflection of Surge Voltage

(Leading Edge of One Pulse)

Inverter

Progressive Wave

Reflected Wave

Progressive wave reflects at the rapid changing point (motor terminal section) of line impedance.

(Twice Surge VoltageApplied to Terminals)

102

Without Filter

(a) Test Circuit

[Inverter Output] [Motor Input]

(b) Result of Waveform Observation (5s/div, 250/div)

Expanded Diagram

With Filter

Inverter Output Motor Input

IM

Surge Voltage Suppression by Filter

Filter

Expanded Diagram

PWM Inverter

103

Filter

Motor Terminal Voltage(Without Filter )

Unless any filter is installed, surge voltage may be generated at the motor terminal, which may affect motor insulation.

Motor

Motor Surge Voltage Suppression by Filter

PWM Inverter

~ ~

~

~ ~

~

104

The solution to 400V class inverter drive problems1. Low surge voltage

Suppresses motor surge voltage, eliminating theneed for the motor surge voltage protection.

2. Low electrical noise (Radiated, Conductive)3. Low acoustic noise 4. Electrolytic corrosion of motor bearings due to shaft voltage

Features of 3-level control

105

(b) Example of Shaft Voltage Measurement (between Shafts) (c) Shaft Voltage Waveform

(Hz)

Commercial Power Supply Drives

Actual Measurement of Shaft Voltage

Commercial Power Drives

(Direct-coupling Side)(Opposite to Direct-coupling Side)

S

h

a

f

t

V

o

l

t

a

g

e

(

m

V

)

Inverter

Inverter Drives

V: Measuring DeviceR: Non-inductive Resistor (1k)

(Stator)(Rotor)

(a) Example of Shaft Voltage Measuring Circuit Inverter: PWMMotor: 3.7 kW, 200 V, 4 polesV/f characteristics: Constant torque

106

Chapter 8Maintenance and Inspection

107

Failure Patterns

Initial Failure Period

Accidental Failure Period Wear-out Failure Period

t

Specified Failure Ratio

Service Lifetime

F

a

i

l

u

r

e

R

a

t

i

o

(

t

)

0ta tb

108

Place Item Checking Item

Schedule

Daily

Periodical

1-yr 2-yr

Whole

Peripheral environment Ambient temperature, humidity, dust, hazardous gases, oil mist, etc.

Whole unit No excessive vibration or noise.

Power supply voltage Check that main circuit voltage or control voltage is normal.

Main Circuit

Whole

Megger check between main circuit terminal and ground terminal

No loose connections

No traces of overheating in components

Clean.

Connected conductor,

Power supply

No distortion in conductor

No breakage or deterioration (cracks, discoloration, etc.) in cables

Transformer, Reactor No odor, excessive beats or noise

Terminal stand No damages

Smoothing capacitor

No liquid leakage

No projection (safety valve) or bulge

Measure electrostatic capacity and insulation resistance.

Relay, Contactor

No chattering at operations

Timer operation time

No roughness on contacts

Resistor

No crack in resistor insulating material

No disconnection

Control Circuit,

Protective

Circuit

Operation check

Balance of output voltage between each phase by inverter single-unit operation

No failure in protective or display circuit by sequence protection test

Component

check

Whole

No odor or discoloration

No excessive corrosion

Capacitor No traces of liquid leakage or deformation

Cooling System Cooling fan

No excessive vibration or noise

No loose connections

Clean the air filter.

Display

Display

All lamps lights correctly.

Clean.

Meter Indicated values are correct.

(From JEMA Information)

Daily Inspection and Periodical Inspection

109

NameNameNameName

Standard Standard Standard Standard

Replacement PeriodReplacement PeriodReplacement PeriodReplacement Period

MethodMethodMethodMethod

Cooling fanCooling fanCooling fa