Siemens 7SA511 manual Tracing Hardware and Software Faults, Troub eshooting Tips

7SA511 Line Protection Relay Maintenance

8.1 Tracing Hardware and Software Faults

As the relay’s protection is almost entirely self-monitored, hardware and software faults are automatically announced. With detected hardware faults, the relay blocks itself. Recognized soft- ware faults cause the processor to reset and restart. If the fault is still present after three restart attempts, the relay will switch itself out of service and indicate this condition by the redBlocked LED on the operator panel.

The relay’s event log and target log data may be useful for maintenance. The event log is under address block 5100, and the target logs for the last three faults are under address blocks 5200, 5300, and 5400, respectively. Refer to Chapter 6, “Displaying System and Relay Information,” for more information on the type of data included in the event log and target logs.

8.2 Troub eshooting Tips

If the relay indicates a defect but none of the LEDs on the operator panel are lit, then perform the following che s:

Are the modules pushed in and lock d properly?

Is the On/Offswitch on the operator panel in the “On” position?

Does the input power have correct polarity and voltage?

Is the input power connected to the proper relay terminals?

￿Has the minifuse in the power supply section blown? Is the relay correctly set and configured?

If the red BlockedLED is lit and the green PowerLED is not lit, the device has recognized an internal fault. To reinitialize the unit, turn the DC auxiliary voltage off then back on using the operator panel On/Offswitch. When the DC auxiliary voltage is off, the relay will lose any event log data, target log data, and configuration settings that have not been saved.

8.3 Inspecting the Power Supply Fuse

The relay’s internal power supply is protected by a fuse. In the event of a blown fuse, you must remove the relay’s front cover and remove the basic module from the housing to inspect the fuse. When required, refer to Chapter 4, “Installation” sections 4.3.1 and 4.3.2 for detailed removal and replacement instructions.

The fuse holder is located at the rear of the basic relay module as shown in Figure 8-1. If the fuse is blown, there is very likely a problem in the internal power supply, and the relay should be returned to the factory for repair.

8-4 July 27, 1995