Allen Bradley Guardmaster 440R Safety Relay Troubleshooting and Configuration Guide

SWS cable length ≤ 30m, it is recommended to use shielded wire. One L11 can drive up to 10 L12s.

Step 5: Check the reset circuit (S34)

If the OUT LED is flashing (waiting for reset), measure the voltage of A2 in connection with S3.

Automatic reset: S34 must be connected to 24V (constant high), and the safety output will immediately turn on after the input is closed.

Monitoring manual reset: S34 requires a pulse from 0V → 24V → 0V, and the low-level time must last for 0.25... 3 seconds. When using the button, the release time should be within this range.

External contact monitoring: The auxiliary contacts of the contactor can be connected in series in the S34 circuit. If the contacts are not closed, they cannot be reset.

Step 6: Check the safety output

Mechanical and Electrical Output (CI/DI/EM/EMD/SI): The output terminal is connected in series with the load. Confirm that the voltage of 13 or 23 is the same as the power supply, and the voltage of 14 or 24 is the same (when the output is ON). If the voltage is normal but the contactor does not engage, measure the contactor coil.

OSSD output (DIS): 14/24 terminal maximum load 1.5A, capacitance 1.6 μ F; The maximum load of terminal 34/44 is 0.5A, with a capacitance of 9 μ F. When the output is ON, the terminal voltage should be close to 24V. If connecting the PowerFlex driver S1/S2 input, it must be grounded together (the COM of the driver is connected to A2).

Auxiliary output: Y32 (DI/DIS/SI) and X32 (EM/EMD) conduct when the safety output is OFF (PNP output). If the safety output is OFF but the auxiliary output does not have 24V, it may be due to internal safety relay adhesion or internal failure, and the module needs to be replaced.

Step 7: EMD Special Input B1/B2

Jogging function: B1 is connected to 24V and L12 is ON → output ON for a set time and then OFF for 500ms.

Can trigger shutdown delay again: Short circuit B1-B2 before configuration. If L12 is turned on again during the shutdown delay period, the timer will be reset.

If the B1 LED lights up but has no waveform, it may be an internal fault.

Security level and maintenance recommendations

7.1 SIL/PL parameters

All GSR models meet the following requirements:

PFH: 1.5E-09~4.5E-09 (applicable to high demand mode)

SIL 3（IEC 61508 / IEC 62061）

Cat 4 / PLe（ISO 13849‑1）

MTTFd: ≥ 252 years

DCavg：98.8%

7.2 Service life and replacement

Electrical lifespan: 10 times of operation (electromechanical output).

After 20 years of use, replacement should be evaluated.

Online replacement: The GSR module supports hot swapping (can be replaced with power on, but must ensure that the safety circuit is disconnected).

7.3 Suggestions for spare parts

Common models: CI (440R-S13R2), DI (440R-D22R2), EM (440R-EM4R2).

Backup wiring terminal (pluggable, module can be replaced without disconnecting).

If using SWS, ensure that the cable length is ≤ 30m and prepare shielded cables.