Presented by

Telematic Ltd

Applications of Surge Protection

Devices

Introduction

Thermionic Valve Technology - Disadvantages

Thermionic Valve Technology - Advantages

<1000 µJ<1000 µJ

Discrete Transistor Technology

<10 µJ<10 µJ

Integrated Circuitry

<1 µJ<1 µJ

Charge accumulation within cloud

+

+

+ +

+

+

_ ___

__

Negative charged cloud base

Updraughts of warm air

Down draughts of

cold air

Surface rain

Progression of a stepped leader

+++

++

+++ +

_

_

_

_

_

Lightning’s annual cost (USA)

Economic$139 Million property damage in

USA$40 Million claims to Factory Mutual

PersonalAverage 70 fatalities

Less obvious cost of strikes

Surges also cause:

System down time

Lost business opportunities

System unreliability

Day off?

Before

Permanent retirement !

After

Coupling Mechanisms for Transients

CAPACITIVE

INDUCTIVE

RESISTIVE

Lightning Strike to Building

200KA

High local potential

Little or no damage occurs to sub-systems within structure

Resistive Coupling into Cabled System

200KA

Remote ‘ground’

High local potential

High potential

across insulation

Standards for Surge Protection

IEC 1000-4-5

European std for transients

FCC Part 68, Bellcore TR-NWT-001089

US Telecommunications

BS6651:1992 Appendix C

recommendations in UK

IEEE/C62.41:1991 , REA PE-60, UL1449

AC power SPD test standards

Sources of Transients

Lightning

Static discharges

Switching transients

Power cable induction

Nuclear Electro Magnetic Pulse

Comparison of Transient Sources

Source Field Density Rise Time

Lightning 3V/m 600V/µs@10km

Static discharge 20kV 2kV/ns at impact

NEMP 50 kV/m 5kV/ns @500km

SPDs act by:

Diverting surge current to earth

Clamping output voltage to a safe level

Does NOT prevent lightning but protects against effects

Surge Protection Devices

Standards for Surge Protection

IEC 1000-4-5

European std for transients

BS6651:1992 Appendix C

recommendations in UK

IEEE/C62.41:1991 , REA PE-60, UL1449

AC power SPD test standards

8/20µs Short-circuit Current Pulse - IEC 60-1

90%

50%

10%

I (10KA)PK

8µs

20µs

t

1.2/50µs Open-circuit Voltage Pulse

1.2µs

50µs

t

90%

50%

10%

V PK

10/700µs Open-circuit Voltage Pulse

10µs

700µs

t

90%

50%

10%

V PK

SPDs in Zone 0 - IEC 60079-14

• Why install SPDs?– High likelihood of lightning induced

transients

– Combustible gases present

– Uncontrolled flashover may cause ignition

Zone 0 Protection - IEC 60079-14

Installation Must be installed in Zone 1

Must be close to Zone 0

Must withstand 10kA 8/20µs test to IEC 60-1

IS Applications

Simple Apparatus Non-energy storing

non-voltage producing

Certified Gives greater confidence

IEEE C62.41 summary

IEEE C62.41Gives recommendations only

Splits installations into Categories

Lots of real-world data

IEEE C62.41-1991

Impulse

Service Entrance Category C3

PanelboardCategory B3

Branch Panel Category A1

10kV(1.2,50µs) 6kV(1.2,50µs)

10kA(8/20µs) 3kA(8/20µs)

Ringwave

6kV/500A 100kHz 6kV/500A 100kHz

IEEE C62.41 Locations

Cat CCat B

Cat A

IEC 1312 protection zones

IEEE C37.90 summary

IEEE C37.90 Standard Surge Withstand Capability (SWC)

Tests for Protective Relays and Relay Systems

Applies to a system and not individual components

SPDs will help comply to the standard

IEC 1000-4-5 summary

IEC 1000-4-5 (801-5) Testing and measurement techniques - Surge

immunity test

Direct lightning is not considered in this standard

Highest test level specified is 4kV

BS 6651 summary

BS 6651 Protection of structures against lightning

Appendix C covers protection of electronic equipment

Gives advice on how to assess lightning risk for an installation the level of protection required

Lightning as a Capacitor

+100MV

Common mode surges

Local Earth

Incoming cablesVoltage shift is the same for both cables

Difference mode surges

Incoming cablesVoltage difference is between cables

Primary Protection Elements

Air spark gap

Carbon spark gap

Gas-filled discharge tube

Spark Gap

2-electrode Gas Discharge Tube

1

2

2-electrode GDT in 2-wire loop

1

2

Electronic

Apparatus

3-electrode gas discharge tube

1

2

Electronic

Apparatus

Secondary Protection Elements

Transient Voltage Surge Suppression Diode

Metal Oxide Varistor

(MOV)

Surge Diodes

Surge Suppression diode

1500W surge rating

Conventional diode

5W steady state rating

Varistors (MOV)

Multiple current paths

Power absorption

throughout pellet volume

Metal oxide particles

Secondary Element Characteristics

MOV Surge Diode

V

I I

V

Device SpeedSensitivity Energy Stability

Air Gap Fast Poor High Poor

GDT Fast Good High Good

Zener V Fast V Good Low Excellent

Transorb V Fast Good Medium Excellent

Varistors V Fast Poor High Poor

Relays V Slow Good Medium Good

Fuses Slow Fair Medium Good

Comparison of Protection Components

Conventional Hybrid SPD

1

2

Multi-stage SPD Operation

Incoming surge GDT Diode Hybrid

1

2

Hybrid Device with Steering Diodes

2

1

Continuous Overvoltage Suppression

2

1

Protection of Panel Equipment

SPDDC Power

Incoming Surge

Protection of Transmitters

Surge

diversion

Incoming surge

Tx

Telemetry Outstation

Telemetry

Equipment

PSTN

RF

I/Olines

SPDs

AC SPD

Terminology - SPD basics

SPD basicsLet-through or limiting

voltage

Working voltage

Maximum leakage current

Surge Protector Applications - Selected by Voltage

Thermocouples mV

RTDs <2V

RS422 <12V

Loadcells <30V

RS232 <25V

Switches 24V,110Vac

Process control loops (4/20mA) 24V/48V

Ultra-sonic level transducers 100V

Terminology - Networks

NetworksBandwidth

Crosstalk

Insertion loss

Surge Protector Applications - Typical solutions

Thermocouples SD07X, TP48

RTDs SD07X, TP48

RS422 SD16R

Loadcells LC30

RS232 SD16X, SD32X

Switches PC30/D,SD150X

Process control loops (4/20mA) SD32X, TP48

Ultra-sonic level transducers CA350

Transmitter protection

SD series circuit

1

2

3

4

5

6

Replaceable fuse module

or loop disconnectMinimal series

resistance

Automatic grounding via DIN-rail

Two lines plus shield

SD vs terminal protectors

Hybrid SPD Shield termination point Automatic grounding Series fusing Line disconnect All in 7mm width

Single component protection No shield termination point Manual grounding per terminal Additional series fusing Additional line disconnect 12-15mm width/loop

plus fuse terminal

plus knife-edge terminal

3-wire transmitter protection

Surge Protection of Weighing System

Junction box

Oil storage tanks

Load cells

Controlcomputer

Weigh bridge

LC30

LC30

4-wire Bridge / 4-wire Line

Supply

Sense

Signal /

4-Wire Field Cable4-Wire Field Cable

CompensatedLoad Cell

CompensatedLoad Cell

LC30

Metal Weighbridge Bonding

Bond Effective system earth Surge protection device

Summation box

To indicator

VP08 - video protection

VP08 installation

Field InstallationMonitoring area

Clipit 100

CA90/CA350 Aerial protector

Telemetry Outstation

Telemetry

Equipment

PSTN

RF

I/Olines

SPDs

AC SPD

RTU Protection

Telemetry

Equipment

PSTN

RF

I/Olines

SPDs

Building Protection

Data

Cable

Telephone

Cable

1a. SPD on Main Electrical Distribution Board

1c. SPD on sub-distribution boards feeding critical areas

3. SPD on inter-building Data Cables

2. SPD on External Telephone Lines

Main

ComputerSPD SPD

SPDSPDTelephone

Exchange

Mains Power

Cable

Communications links between buildings

Damage caused by surge on

communications link cable

Remote earth

Local AC supply

Local AC supply

Protection for Inter-building Network Link

NP

FL

NP

Outside

Building 1 Building 2

Network running through Different Building Areas

1

2

Industrial area within building

High transientovervoltage

generated by heavymachinery,

welding equipment& power cables

Office area

NP

NP

Network characteristics

Signal level

Bandwidth or bits/s

Connector type

In line resistance

Typical LAN Applications

Thin ethernet

NP08/B

Thick ethernet

NP08/N

Token Ring

NP08/2R

Typical industrial network Applications

RS232

SD16X, SD16

DP16/D, DP16

RS423

SD16R, SD16X

PC16/D, PC16

RS422 / RS485

SD16/R, SD16X

NP16/S

Common industrial bus systems

Allen Bradley data highway plus PC16/D, SD32R

Foundation Fieldbus SD32R, SD55R

HART SD32X, SD32

Honeywell DE SD32X, DP30/D

Interbus SD32R, NP16/S

Modbus SD32R, NP16/S

Profibus SD32R, NP16/S

WorldFIP SD32R, NP16/S

Bus Powered Systems

NP08/N - Thick ethernet

Thick Ethernet installation

NP08/B - Thin ethernet

Thin Ethernet installation

Allen Bradley Data Highway Plus

Category 5 installation

PSTN ringing voltage

0

50

100

150

200

250

Vol

tage

Typical PSTN Applications

UK jack and socket - office

DP200/4/I

Krone strip - exchange

PX200/10

Telemetry outstation

DP200/D

mSAPN

Typical Private Wire Applications

Krone strip - exchange

DP16/PX

Telemetry outstation

SD16X

DP16/D

mSA16

DP200/4/I

Earth terminal

DP200/4/I installation

PSTN connection

DP200/D installation

MOV surge clamping

AC Power Line Protection

Power cables transient sources

Lightning

Load switching

Welding equipment

Elevators/lifts

Applicable standards

IEEE Std. 587-1980 (obsolete)

ANSI/IEEE C62.41 1991

IEC 801-4, -5

Spur vs Series Connection

ProtectedLoad

L

N

G

SPD

SPD

Delta Network of Varistors

L

N

G

Fuse protected network

Star-connected Varistors

L

LL

NG

1

3

2

Fuses not shown for

clarity

Fusing AC Power SPDs

L

N

G

SPD

SPD

MA05, MA10 applications

MA05/D, MA10/D

PLC power supply

Instrument PSU

MA05/SC, MA10/SC

Fire/burglar alarm panel

Computer PSU

MA05/I, MA10/I

Fax Machine

Computer

Grounding for Lightning Protection - Principles

Divert current as soon as possible

Use dedicated low impedance connection

Make sure other systems are bonded to it,

once!

Convert series-mode current into common-

mode voltage

Lightning strike to Aeroplane

Different types of Earth

Mains Protective Earth Essential for personnel safety

Carries leakage currents

Surge Protective Earth Must be able to carry huge currents

Low voltage drop

Instrument or Computer Earth Needs to be kept from ‘dirty’ earth

Star-connected System Earths

Telecomms Instrumentation

Computers

Cable impedance

Inductance + Resistance

Recommended earthing philosophy

Common Grounding System

Incoming SurgeSPD DC Power

Todistribution

ground

Preferred Grounding System

Incoming SurgeSPD DC Power

Todistribution

ground

Disastrous Grounding System

Incoming SurgeSPD DC Power

Todistribution

ground

SPDs with IS Barriers

Hazardous Area

SPD IS Barrier

Safe Area

TX

SPD

SPDs with Zener Barriers

SPDs with Galvanic Isolation

Galvanic Isolator

Hazardous Area Safe Area

TX

SPDSPD

Conclusion

Protect equipment;-

Exposed to lightning surges & other transients

With difficult or remote access for maintenance

Critical to plant operation & control

Critec AC power products

SRF Range

High current surge protection and filtering (50 - 120kA)

Recommend MA230, MA103 or MA2003

MT Range

Two terminal device containing 5 MOVs (40 - 120kA)

Recommend MA230, MA103 or MA2003

MPM Range

Box containing three MT units (50kA L-N)

Recommend MA230, MA103 or MA2003

Critec LAN protectors

LAN-TYPE-1E

Token Ring protector

Recommend NP08/2R

LAN-TW280

TwinAx protector

Recommend NP16/T

LAN-BNC

Thin Ethernet

Recommend NP08/B

LAN-N

Thick Ethernet

Recommend NP08/N

Critec data protectors

LSAC Range

4A AC data SPD

Recommend MA05 or SD150X (higher surge rating)

LSCP and LSSC Range

High frequency coaxial SPDs

Recommend CA90 or CA350

LSJK and LSEK Range

Includes GDT, MOV and surge diode

Recommend SD series