MSR131 Troubleshooting Guide Rev C

MSR131 Toubleshooting Guide Rev C.doc Page 1 of 22 December 27, 2005

Troubleshooting Safety Relay Based Systems

MSR131

Safety Relay Troubleshooting Guide


Table of Contents

1) Introduction......................................................................................................................................... 3

2) Power Supply ...................................................................................................................................... 4 a) FAQ: What is the inrush current on power-up?............................................................................................................5

3) Input Circuit – 2NC ............................................................................................................................ 7 a) FAQ: How much inrush current is present at the inputs?...........................................................................................10

4) Input Circuit – Distribution Block .................................................................................................... 11

5) Input Circuit – Light Curtain ............................................................................................................ 12 a) FAQ: Once the input circuit is opened, how long must it stay open?..........................................................................13 b) FAQ: Under what conditions is the order of input circuit closing important?.............................................................13

6) Safety Mat Input ............................................................................................................................... 14 a) FAQ: What causes only one output LED to turn on? ..................................................................................................15

7) Reset Circuit...................................................................................................................................... 15 a) FAQ: How soon after the inputs are closed can the reset button be pressed? ............................................................17

8) Monitoring Circuit ............................................................................................................................ 18

9) Output Circuits.................................................................................................................................. 20

10) Timing Requirements........................................................................................................................ 21

11) Single Point Lesson........................................................................................................................... 21


1) Introduction

The troubleshooting process for the MSR131 safety relay follows a straight forward process. The process starts with the power supply and follows the normal sequence of events that take place in the relay. The troubleshooting process is as follows:

1. Power 2. Inputs 3. Reset 4. Monitoring 5. Outputs

The MSR131 safety relay goes into a lockout state when it detects a fault condition. The fault condition can be either external or internal to the MSR131, as the MSR131 monitors external devices as well as itself. This lockout state prevents the safety outputs from being energized, until the fault condition is corrected and the MSR131 is satisfied. If an external fault is corrected, the MSR131 is reset in one of two methods:

1. Cycle an input device (the preferred method), or 2. Cycle the power.

In many cases, the fault will be either an open-circuit or a short-circuit condition. In these cases, a digital multimeter can be used to accomplish the troubleshooting. An oscilloscope is needed when timing issues are suspected of causing lockouts. Note: The measurements in this document were taken on sample products. Actual measurements will vary from unit to unit, as well as with temperature. In this guide, the reader is asked to make measurements with a multimeter. An example of the terminology used is “S12/S22”, where one test lead is placed on terminal S12 and the other terminal is placed on terminal S22. FAQ = Frequently Asked Question EOT = End of Troubleshooting

!Troubleshooting safety relay based systems sometimes requires the application of power. Troubleshooting must be performed by trained persons familiar with safety publications ANSI NFPA70E and ANSI Z244.1 and local applicable codes.


2) Power Supply The power supply is protected by electronic current limiting. If a short circuit or overload occurs, the resistance goes up to prevent damage to the MSR131. When the fault is cleared, the resistance returns to normal, and the MSR131 begins to operate properly. See Safety Mat inputs for further details.

Step P1 Is power LED on?

If not, go to Step P2. If blinking, go to Step P4 If yes, go to Input Circuits.

Step P2 Measure supply voltage at A1/A2 for 24VDC or 115VAC, depending on the model used.

If OK, go to Step P3. If not, verify that the equipment power switch is set to ON. Is the equipment connected to the power source? Are the power supply fuses blown? Is the unit rated for the appropriate voltage – see label on side of unit? Go to Step P1. As a reference, the current used by the MSR131, with its safety outputs energized, is shown in the side table. This table show the typical current when the MSR131 is functional and its safety outputs are energized.

Reference Information: Power Supply Current

The power supply current depends on the type of inputs used. Use an ammeter to measure the current. Values shown with safety outputs energized.

Light Curtain 23mA DC @ 20.4V DC

28mA DC @ 24.0V DC 31mA DC @ 26.4V DC 19mA AC@ 98V AC 24mA AC@115V AC 26m A AC@126VAC

2 NC Contacts 70mA DC @ 20.4V DC 85mA DC @ 24.0V DC 95mA DC @ 26.4V DC 31mA AC @ 98V AC

38mA AC @ 115V AC 42mA AC @ 126V AC Safety Mat/Crossfault 115mA DC @ 24VDC 45mA AC @ 115VAC

440R-C23139 (24V AC/DC)440R-C23137 (115V AC)+V -V

Check PowerSupply on Side Label

24

Volts

DMM

Example for 24VDC

24

Amps

DMMExample for 24VDC

OutputActive

InputsClosed

S21

13

A1

23

33

41

51

Y31

S11

S11

S22

S12

S52

X1

X2

X3

X4

14

34

42

24

A2

52

Y1

Y2

S33

S34

Y32

Y35

Y30

AC

PWR

24VDC

Circuit Protection

(+) (-)

CH1 CH1

CH2

CH1

&

CH2CH2

StartLogic

CH2CH1

ResetStart


a) FAQ: What is the inrush current on power-up?

The worst case inrush occurs at the highest supply voltage with the MSR131. The inrush current is essentially the same regardless of whether or not the safety outputs energized on power up. At 26.4V DC, the inrush current of the power supply is 120mA. This pulse lasts for about 10ms. At 126VAC, the peak inrush is 150mA, and it decays exponentially to a steady state value within 3 cycles. DC Power Inrush AC Power Inrush

Step P3 Measure the internal supply voltage of the MSR131 - S11/S21 should be 17 to 40 VDC. The internal voltage is not tightly regulated and depends on the external power supply. If OK, go to Input Circuits.

440R-C23139 (24V AC/DC)440R-C23137 (115V AC)+V -V

Should be17 to 33 VDCdepending

on Supply Voltage

24

Volts

DMM

OutputActive

InputsClosed

S21

13

A1

23

33

41

51

Y31

S11

S11

S22

S12

S52

X1

X2

X3

X4

14

34

42

24

A2

52

Y1

Y2

S33

S34

Y32

Y35

Y30

AC

PWR

24VDC

Circuit Protection

(+) (-)

CH1 CH1

CH2

CH1

&

CH2CH2

StartLogic

CH2CH1

ResetStart

10ms

120mA

150mA


Step P4 Pop out the top front terminal block (with S11). Did the Power LED stop blinking?

If yes, turn off power to the unit. Use your ohm meter and check for shorts between the CH1 and CH2 circuit. If a safety mat is connected to the MSR131, check for objects on the safety mat.

Pop out the top terminal block. Check for shorts. If a short is found, trace the input wiring and remove the short. Re-insert the top connector, and apply power. Go to Input Circuits.


3) Input Circuit – 2NC The typical 2 normally closed (NC) series circuit is wired as shown below. This arrangement employs redundancy (two circuits) and diversity (one pull up and one pull down). The internal relay to CH1 is pulled up by the external interlocks or e-stops to 24V at S11. A jumper is connected from S11 to S52 to supply power to CH2. CH2 is pulled down to ground by the external interlocks or e-stops to S21. Crossfaults, shorts from CH1 to CH2, can be detected by the diversity principle – the Power LED blinks.

Operation With 2NC circuits, the safety outputs de-energize when either CH1 or CH2 opens. If one channel opens, then the other channel must also open before the safety outputs can re-energize. The timing between the inputs is flexible:

1) CH1 can open before or after CH2 - the order in which the channels open and close is not critical. 2) the first channel that opens can close before the second channel opens and closes. 3) there is no time within which the second channel must operate; it could operate seconds, minutes or even days later.

After both inputs have been opened and then closed, the input is said to be satisfied. The MSR131 is ready to check the reset and monitoring circuit. If those circuits are satisfied, the safety outputs will be energized.

Gate Interlocks or E-Stops

Channel 1

Channel 2

+V -V

OutputActive

InputsClosed

S21

13

A1

23

33

41

51

Y31

S11

S11

S22

S12

S52

X1

X2

X3

X4

14

34

42

24

A2

52

Y1

Y2

S33

S34

Y32

Y35

Y30

AC

PWR

24VDC

Circuit Protection

(+) (-)

CH1 CH1

CH2

CH1

&

CH2CH2

StartLogic

CH2CH1

ResetStart


Step I1 Are the CH1 and CH2 LEDs on?

If yes, go to Step Reset Circuit. If only CH1 LED is on, then an open circuit exists on CH2. Go to Step I2. If only CH2 LED is on, then an open circuit exists on CH1. Go to Step I2. If neither CH1 LED nor CH2 LED is on, then both CH1 and CH2 circuits must be open. Go to Step I2.

Step I2 At the MSR131, measure the cross channel voltages. This should confirm the input LED Status:

Relay Terminals Voltage Look for: Input LED S52/S22 24V Both Channels are OK Both on S21/S12 24V S52/S22 0V Both Channels are open. Both off S21/S12 0V S52/S22 24V Channel 1 is open. CH2 on S21/S12 0V S52/S22 0V Channel 2 is open. CH1 on S21/S12 24V

When troubleshooting 2NC circuits, the easiest approach is to measure the cross channel voltage at each of the devices. Open the cover of an interlock to expose the wiring terminals. . The two contacts closest to the actuator are the safety contacts. Using a voltmeter, measure the voltage from Channel 1 to Channel 2.

Cross channel measurement Contact measurement

CH1 Safety Contacts

CH2 Safety Contacts


Check the input devices for open circuits. The following two diagrams show typical examples of wiring 2NC series circuits. With all the input devices closed and the MSR131 powered, measure the cross channel voltages at each of the input devices until a voltage difference is found. The open circuit lies between the device that showed 0V and the device the showed 24V. Check the connections, terminals, and wiring for an open circuit. The actual voltage shown is a nominal 24VDC; the actual voltage can range from 17 to 40V.

Open Circuit on CH1 Open Circuit on CH2

Reference Information: Input Currents The currents going into S12 (CH1) and S22 (CH2) depend on the supply voltage. Use a DC ammeter to measure these currents. VSupply CH1 CH2 20.4V DC 25mA DC 31mA DC 24.0V DC 30mA DC 37mA DC 26.4V DC 34mA DC 41mA DC 97.8V AC 28mA DC 34mA DC 115V AC 33mA DC 40mA DC 126.5V AC 37mA DC 44mA DC


440R-C23139 (24V AC/DC)440R-C23137 (115V AC)

+V -V

0V0V 24V


440R-C23139 (24V AC/DC)440R-C23137 (115V AC)

+V -V

24V

OutputActive

InputsClosed

S21

13

A1

23

33

41

51

Y31

S11

S11

S22

S12

S52

X1

X2

X3

X4

14

34

42

24

A2

52

Y1

Y2

S33

S34

Y32

Y35

Y30

AC

PWR

24VDC

Circuit Protection

(+) (-)

CH1 CH1

CH2

CH1

&

CH2CH2

StartLogic

CH2CH1

ResetStart

OutputActive

InputsClosed

S21

13

A1

23

33

41

51

Y31

S11

S11

S22

S12

S52

X1

X2

X3

X4

14

34

42

24

A2

52

Y1

Y2

S33

S34

Y32

Y35

Y30

AC

PWR

24VDC

Circuit Protection

(+) (-)

CH1 CH1

CH2

CH1

&

CH2CH2

StartLogic

CH2CH1

ResetStart

0V0V


a) FAQ: How much inrush current is present at the inputs?

When the actuator is inserted into an interlock, for example when a safety gate is closed, the inrush current to at the inputs of the MSR131 is 90mA. This inrush lasts for about 100ms. The measurements below were taken on a unit powered by 24VDC. The figures below show the current waveform when the MSR131 is set for automatic and monitored reset. The difference in the waveform is due to the safety outputs becoming energized when the MSR131 is set up for automatic reset.

Inrush Current with Auto Reset Inrush Current with Manual Reset

80ms 100ms

90mA

CH1

CH2

90mA


4) Input Circuit – Distribution Block When troubleshooting devices connected to the distribution blocks, the order in which the devices are connected becomes important. The picture and wiring diagrams show that the connection flow. Not that the 6-pin 8-port flows through the even side and then through the odd side. The 4-pin 8-port flows in numerical order. This can be used to help identify the location of an open circuit, as described in the 2NC section above.

J2 J81 5

2 6 2 6 2 6

1 5 1 5J7 J3

2 6 2 6

1 5 1 5J1

Brown/Yellow

White/Green

Brown/Green

White/Yellow

J8 J7 J2

24242424

13131313J1

Brown

White

Blue

Black

898R-P68MT

898D-48LT

6-Pin QD

4-Pin QD


5) Input Circuit – Light Curtain The MSR131 is designed to interface with light curtains. Light curtains with solid state outputs can be wired as shown below. These light curtains are typically powered by 24VDC. When an AC powered MSR131 is used (shown on right), the light curtain ground must be referenced to the MSR131 internal ground (S21). Solid state light curtains have two PNP type outputs called output signal switching devices (OSSD). The light curtain detects a crossfault, which is a short between the two OSSD outputs; the MSR131 does not detect this fault.

DC Powered MSR131 AC Powered MSR131

Step LC1 With the light curtain made (nothing between the sender and receiver), does the voltage at terminals S12 and S52 measure 24VDC. [With the light curtain broken (object between the sender and receiver), the voltage at terminals S12 and S52 should measure 0VDC.]

If yes, Go to Step LC2. If not, check to make sure the ground reference of the light curtain is the same as the MSR131. For DC powered MSR131’s, this can be A2 or S21. For AC power MSR131’s, the reference must be to S21. If either S12 or S52 measures zero volts, check the wiring going back to the light curtain.

Step LC2 Press the reset button. Do CH1 and CH2 LEDs turn on?

If yes, go to Step Outputs. If not, go to Step Reset Circuit.

Reference Information: Light Curtain Output Currents Use a DC ammeter to measure these currents.

VSupply Ch1 Ch2 19.2VDC 28mA 24mA 24.0VDC 36mA 31mA 26.4VDC 40mA 35mA

The MSR131 power supply does not play a role in

determining these currents.


Note: Light curtains perform their own diagnostics. For example, a crossfault from CH1 to CH2 will be detected by the light curtain, not by the MSR131. Faults detected by the light curtain are usually indicated by red blinking LEDs on the light curtain. This troubleshooting guide is not intended to cover light curtain troubleshooting.

a) FAQ: Once the input circuit is opened, how long must it stay open?

This is known as the recovery time. Once an input is opened, it must stay open for at least 100ms. This gives the internal circuitry enough time to get itself ready for the next demand on the safety system. It is possible to turn light curtains off and then back on within 100ms. If this happens, the MSR131 safety outputs will remain in the de-energized mode, with one output on (typically CH2) and the other output off (typically CH1). To correct this condition, simply break and make the light curtain again.

b) FAQ: Under what conditions is the order of input circuit closing important?

In rare applications, two independent devices are connected like a light curtain: S12 and S52 are switched to 24V, and S21 is jumpered to S22. In addition, automatic reset is used. Under these conditions, CH2 must close before or at the same time as CH1. If this sequence is not performed properly, then the CH1 output will be on, but the CH2 output will not turn on. To correct this situation, modify the sequence of operation or used monitored reset


6) Safety Mat Input Safety mats can also be connected to the MSR131. The wiring example below shows two parallel plate type safety mats connected in series. A current flows through the safety mats at all times to detect an open circuit. The MSR131 uses crossfault detection to detect someone stepping on the mat. When someone steps on the mat, CH1 is shorted to CH2, and the safety outputs are de-energized. The Power LED blinks to indicate the presence on the mat; all the other LEDs are off.

Power Supply Current (24VDC Power to A1/A2): The figure below shows how the current behaves when the safety outputs are off, on and when some steps on the safety mat.

Safety Outputs OFF

Safety Outputs ON

Safety Mat Activated

30mA

78mA

113mA

OutputActive

InputsClosed

S21

13

A1

23

33

41

51

Y31

S11

S11

S22

S12

S52

X1

X2

X3

X4

14

34

42

24

A2

52

Y1

Y2

S33

S34

Y32

Y35

Y30

AC

PWR

24VDC

Circuit Protection

(+) (-)

CH1 CH1

CH2

CH1

&

CH2CH2

StartLogic

CH2CH1

ResetStart

Safety Mat 1 Safety Mat 2


a) FAQ: What causes only one output LED to turn on?

This occurs when a safety mat is connected to the MSR131 configured for automatic reset. The recovery time of the MSR131 is rated at 100ms. It is possible to drop a tool, or bounce something on the safety mat, such that the output turns off. The mat is not actuated long enough for the MSR131 to complete its internal cycle. Typically, the CH2 LED will be off; occasionally CH1 will be off. To clear this condition, step on and off the mat. If this problem persists, consider changing to monitored reset or seek an alternative relay (like the MSR23M or 440F-C4000D).

7) Reset Circuit Operation The MSR131 provides two terminals for reset: S33/S34. There are two types of reset functions: automatic and monitored. Automatic –To configure the MSR131 for automatic reset, jumpers must be added between X1/X2, X3/X4 and S33/S34. The MSR131 safety outputs are energized immediately after the inputs and monitoring circuits are satisfied. Monitored – To configure the MSR131 for monitored reset, remove jumpers from X1/X2 and X3/X4. Connect a normally open contact, typically a manually operated pushbutton, between S33/S34. This normally open contact must be closed after the inputs are satisfied. If the monitoring circuit is also satisfied, the safety outputs will be energized.

Automatic Reset Monitored Reset

When CH1 closes, voltage is applied to S33. This voltage is then applied to S34 and Y2 through the jumper or the reset contact. The Start LED turns on when S34 is powered by the circuit from S33.

OutputActive

InputsClosed

S21

13

A1

23

33

41

51

Y31

S11

S11

S22

S12

S52

X1

X2

X3

X4

14

34

42

24

A2

52

Y1

Y2

S33

S34

Y32

Y35

Y30

AC

PWR

24VDC

Circuit Protection

(+) (-)

CH1 CH1

CH2

CH1

&

CH2CH2

StartLogic

CH2CH1

ResetStart

OutputActive

InputsClosed

S21

13

A1

23

33

41

51

Y31

S11

S11

S22

S12

S52

X1

X2

X3

X4

14

34

42

24

A2

52

Y1

Y2

S33

S34

Y32

Y35

Y30

AC

PWR

24VDC

Circuit Protection

(+) (-)

CH1 CH1

CH2

CH1

&

CH2CH2

StartLogic

CH2CH1

ResetStart


Step R1 Measure the voltages at the terminals under the conditions of the inputs and outputs, shown below. Automatic Reset

Inputs Outputs S33/S21 S34/S21 Status & Action Both Open De-energized 0VDC 0VDC MSR131 working OK Both Closed De-energized 24VDC 0VDC When CH1 closes, voltage is applied to S33.

The Start LED turns on when S34 is powered by the jumper from S33. If the Start LED does not turn on and S34/S21 is 0VDC, then look for an open circuit from S33 to S34.

Both Closed De-energized 24VDC 24VDC Look for an open monitoring circuit Y1/Y2. Go to the Monitoring Circuit.

Monitored Reset

Inputs Outputs S33/S21 S34/S21 Status & Action Both Open De-energized 0VDC 0VDC MSR131 working OK Both Closed De-energized 24VDC 0VDC When CH1 closes, voltage is applied to S33.

The Start LED turns on when S34 is powered by the closing of the reset contact. If the Start LED does not turn on and S34/S21 is 0VDC, then look for an open circuit from S33 to S34.

Both Closed De-energized 24VDC 24VDC Look for 1 of 2 conditions: 1) If the Start LED is on, then the reset contact is stuck in the closed position and was closed prior to the inputs being satisfied; or 2) If the Start LED turns on and off when the reset button is pressed and released, then look for an open monitoring circuit Y1/Y2. Go to the Monitoring Circuit.


Step R2 Use an oscilloscope to measure the reset signal. Place a small resistor; 10 ohms will work, in series with S33/S34. Connect the oscilloscope leads across the resistor. Trigger the scope to capture the single shot. The reset signal of an 115VAC powered MSR131 is 70mA and lasts for 34mS. For a 24V DC powered MSR131, the reset current is 55mA and lasts for 44ms. 115V AC Powered MSR131 24VDC Powered MSR131

a) FAQ: How soon after the inputs are closed can the reset button be pressed?

100ms. When monitored manual reset is used, the reset contacts cannot be closed until at least 100ms after the inputs are satisfied.

70mA

34mS

55mA

44mS


8) Monitoring Circuit Operation

The MSR131 provides two terminals for monitoring of external devices. The typical purpose of the monitoring circuit is to assure the status of external devices, prior to energizing the safety outputs. In the examples below, the output contactors (on left) and the interlock solenoid (on right) must be in the non-actuated position before the MSR131 safety outputs can be energized. The MSR131 requires this circuit to be closed before energizing its safety outputs. After the safety outputs are energized, the monitoring circuit is not used.

Monitoring Output Devices (Contactors) Monitoring Input Devices (Guardlocking Interlock) When CH1 closes, voltage is applied to S33. When the reset circuit, S33/S34 is closed, voltage is then applied to Y2. If the monitoring circuit is closed, the voltage is then applied to Y1 to allow completion of the monitoring function. The monitoring signal is short in duration (see Step M2). The Y1/Y2 circuit is opened as soon as the external devices (ie. contactors) are energized.

MK2K1

L1L2L3

K2

K1

+V -V

OutputActive

InputsClosed

S21

13

A1

23

33

41

51

Y31

S11

S11

S22

S12

S52

X1

X2

X3

X4

14

34

42

24

A2

52

Y1

Y2

S33

S34

Y32

Y35

Y30

AC

PWR

24VDC

Circuit Protection

(+) (-)

CH1 CH1

CH2

CH1

&

CH2CH2

StartLogic

CH2CH1

ResetStart

OutputActive

InputsClosed

S21

13

A1

23

33

41

51

Y31

S11

S11

S22

S12

S52

X1

X2

X3

X4

14

34

42

24

A2

52

Y1

Y2

S33

S34

Y32

Y35

Y30

AC

PWR

24VDC

Circuit Protection

(+) (-)

CH1 CH1

CH2

CH1

&

CH2CH2

StartLogic

CH2CH1

ResetStart

Guardlocking Interlock


Step M1 Measure the voltages at the terminals under the conditions of the inputs and outputs, shown below.

Automatic Reset

Inputs Outputs Y2/S21 Y1/S21 Status & Action Both Open De-energized 0VDC 0VDC MSR131 working OK Both Closed De-energized 24VDC 0VDC When CH1 closes, voltage is applied to Y2

through the reset circuit (S34) and the Start LED is on. Since voltage is at Y2, look for an open circuit from Y2 to Y1.

Both Closed Energized 24VDC 24VDC MSR131 working OK Monitored Reset

Inputs Outputs Y2/S21 Y1/S21 Status & Action Both Open De-energized 0VDC 0VDC MSR131 working OK Both Closed De-energized 0VDC 0VDC Voltage is applied to Y2 by the closing of

the reset contact. Look for an open circuit in the reset circuit. . Go to the Reset Circuit.

Both Closed De-energized 24VDC 0VDC Voltage is applied to Y2 by the closing of the reset contact. Look for an open circuit in the Y2/Y1 circuit.

Step M2 Use an oscilloscope to measure the monitoring signal current. Place a small resistor; 10 ohms will work, in series with Y2/Y1. Connect the oscilloscope leads across the resistor. Trigger the scope to capture the single shot. The monitoring current of an 115VAC powered MSR131 is 65mA and lasts for 34mS. The source of the monitoring current is S33. The current enters S34 and is split. Approximately 5mA is used by the MSR131, and the remaining 65mA is diverted to the monitoring circuit.

650mv/10 ohms = 65mA

34mS


9) Output Circuits The output circuits are redundant voltage-free, electromechanical contacts. Initial contact resistance should be less than 1 ohm. Over the life of the contacts, resistance may go up, but should remain less than a couple ohms. Follow the steps below using the figure below as a guide.

Step O1 Check the supply side of the output contacts. Does the voltage at terminals 13, 23, 33 and 41 with respect to the appropriate power supply reference (this may not be the same as A2 or S21) meet expectations?

If yes, go to Step O2. If not, check the upstream fuses and wiring.

Step O2 With the CH1 and CH2 LEDs on, do the voltages on the load side of the safety relay meet expectations?

If yes, go to Step O3. If not, then the output contact in the MSR131 may be worn or contaminated. To confirm this, remove the power wires from the terminals (both the supply and load side) and use an ohm meter to measure the contact resistance. [This is not shown in the figure above.] Cycle the inputs and measure the resistance a few times, as the circuit may be intermittent.

Step O3 The output voltage is ok. Does the load energize?

If yes, then MSR131 works OK. EOT. If not, the trouble resides with the wiring to the load or the load itself. The load may be disconnected or not functioning properly. Measure the voltage at the load. Measure the current going to the load. Replace the load, if necessary.

Step O1

Step O2

120

Volts

DMM

120

Volts

DMM

0.235

Amps

DMM120

Volts

DMM

A1 A2

A1 A2

A1 A2

A1 A2

MSR138.1DP

Gnd120VACPower

K1

K2

K3

K4

13

23

33

41

51

14

34

42

24

52

CH2CH1

Step O3


10) Timing Requirements Time requirements in the table below should be followed to make sure that safety circuits are monitored in a correct manner. Incomplete de-energizing of either internal safety channels or too short time before reset will be detected as circuit failure and requires one correct cycling of inputs before reset. Definitions: Response time via E-Stop: Time from opening input contacts until opening the safety outputs. Response time via loss of supply: Time until opening the safety outputs when supply is switched off. Recovery time: Required time after relay has de-energized before it shall be energized again. Auto-Reset: Unit resets as soon as inputs are closed provided all internal relays have been de-energized before. Monitored reset: Reset is only possible if reset loop S33-S34 is open before inputs are closed and will be closed after inputs are closed for at least 200ms. This prevents automatic reset when the reset button is bridged. All times are maximum or minimum times. Computer (PLC) controlled actuation of the reset signal must not occur before the recovery time has elapsed and should be maintained for at least 100ms.

Time Description Time

Via E-Stop <15ms Response time

Via loss of supply <100ms

Via E-Stop <100ms

With monitored reset <100ms Recovery time

Via loss of supply <250ms

Via Reset button <60ms

Via Auto-Reset <100ms Switch-on delay

Via supply <200ms

Reset Signal duration >100ms

11) Single Point Lesson The following page contains a simplified “single page” troubleshooting guideline.

MSR131 Troubleshooting Guide

MSR131 Toubleshooting Guide Rev C.doc Page 22 of 22

Power LED

Start LED

CH1 IN

LED

CH2 IN

LED

CH1 LED

CH2 LED

S. S. Y35

Inputs

S. S. Y32

Outputs

Gate

Output Devices

Check

On

Reset On

On

On

Off

Off

On

Off

Closed Off When pressing the reset button, the Start LED turns ON, but outputs do not turn ON. Check the monitoring loop between Y1 and Y2; it should be a closed circuit.

On

Off

On

Off

On

Off

Off

Off

Closed Off 1) Check the gate switch circuit going to S21 and S22; it should be a closed circuit. 2) Check the circuit between S11 and S52; it should be a closed circuit. If the gate is opened, the CH1 IN LED and CH1 LED will turn off. If gate is re-closed again, CH1 IN LED will turn on.

On

Off

Off

On

Off

On

Off

Off

Closed Off 1) Check the gate switch circuit going to S12 and S52. The circuit may have opened while the gate was closed. If the gate is opened, the CH2 IN LED and CH2 LED will turn off. If the gate is re-closed again, CH2 IN LED with turn on.

Blinking

Off

Off

Off

Off

Off

Off

Off

Closed Off Check for short circuit across the inputs: S11 to S21, S11 to S22, S12 to S21, or S12 to S22.

On

On

On

On

Off

Off

On

Off

Closed Off Check the Reset button; it may be shorted or held in the closed position.

Off

Off

Off

Off

Off

Off

Off

Off

Closed Off Check power applied to A1 and A2.

On

On

On

On

On

On

On

On

Closed Off 1) Check for power at terminals 13, 14, 23 and 24. 2) An internal component failure may have occurred in the MSR131.

This troubleshooting guide assumes that the MSR131 has been wired per the schematic shown. This schematic shows connections that demonstrate the functionality of the MSR131. Additional components are necessary to complete the safety system. Configuration: Dual Channel Safety Gate, Manual Reset, Output Monitoring Maximum Allowable Input Resistance: 45 ohms

X4 Y30 S31 Y32A2 Y1 Y2 X1

S11 13 23 33S22 41 51 51

Y35 42 52 52 X2 14 24 34

A1 S33 S34 S52 X3 S11 S12 S21

PWR

START

CH1 IN

CH2 IN

CH1

13 23 33 41 51

14 24 34 42 52

CH2

MSR131RTP

MSR131RTP

Reset

InputsClosed

OutputActive

L2

L1 (120 VAC)

S33S52S21 S22S12 S34

Y1X4A2 X2 Y2Y30

Y31

X1 Y35X3 Y32

A1 S11 S11

14 24

13 3323 41 51 L1

K1

L2

K2

L3

34 42 52

K1 K2M

Dual Channel Gate Interlock, Monitored Manual Reset,Dual Channel Output, Monitored Output

open

closed

24V Ground

24V DC

Documents

MSR131 Troubleshooting Guide Rev C