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Section 5: Testing and Maintenance
7SR24 relays are maintenance free, with no user serviceable parts.
5.1
Periodic Tests
During the life of the relay, it should be checked for operation during the normal maintenance period for the site
on which the product is installed. It is recommended the following tests are carried out:-
1. Visual inspection of the metering display
2. Operation of output contacts
3. Secondary injection of each element
5.2
Maintenance
Relay failure will be indicated by the 'Protection Healthy' LED being off or flashing. A message may also be
displayed on the LCD. In the event of failure Siemens Protection Devices Ltd. (or the nearest Siemens office)
should be contacted – see defect report sheet in section 5.3.
The relay should be returned as a complete unit. No attempt should be made to dismantle the unit to isolate and
return only the damaged sub-assembly. It may however be convenient to fit the withdrawable relay to the outer
case from a spare relay, to avoid the disturbance of relay panel wiring, for return to Siemens Protection Devices
Ltd. The withdrawable relay should never be transported without the protection of the outer case.
5.3
Troubleshooting
Table 5-1
Troubleshooting Guide
Observation
Relay does not power up.
Relay won't accept the password.
Protection Healthy LED flashes
LCD screen flashes continuously.
Backlight is on but no text can be seen.
Scrolling text messages are unreadable.
Relay displays one instrument after
another with no user intervention.
©2010 Siemens Protection Devices Limited
7SR242 Duobias Commissioning & Maintenance Guide
Action
Check that the correct auxiliary DC voltage is applied and that the
polarity is correct.
The Password being entered is wrong. Enter correct password.
If correct password has been forgotten, note down the Numeric
Code which is displayed at the Change Password screen e.g.
Change password
= 1234567
To retrieve the password, communicate this code to a Siemens
Protection Devices Ltd. representative.
General failure. Contact a Siemens Protection Devices Ltd.
representative.
The LCD has many possible error messages which when
displayed will flash continuously. These indicate various processor
card faults.
General failure. Contact a Siemens Protection Devices Ltd.
representative.
Adjust the contrast.
Adjust the contrast.
This is normal operation, default instruments are enabled.
Remove all instruments from the default list and only add those
that are required.
(See Section 2: Settings and Instruments).
Chapter 6 Page 54 of 57
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