P341/EN O/B11 Operation Guide
CHAPTER 3 Commissioning and
Page 12/80 Maintenance
MiCOM P341
4.2.2.2 Without an IRIG-B signal
If the time and date is not being maintained by an IRIG-B signal, ensure that cell
[0804: DATE and TIME, IRIG-B Sync] is set to ‘Disabled’.
Set the date and time to the correct local time and date using cell [0801: DATE and
TIME, Date/Time].
In the event of the auxiliary supply failing, with a battery fitted in the compartment
behind the bottom access cover, the time and date will be maintained. Therefore
when the auxiliary supply is restored the time and date will be correct and not need to
be set again.
To test this, remove the auxiliary supply from the relay for approximately 30 seconds.
On re-energisation, the time in cell [0801: DATE and TIME, Date/Time] should be
correct.
4.2.3 Light Emitting Diodes (LEDs)
On power up the green LED should have illuminated and stayed on indicating that
the relay is healthy. The relay has non-volatile memory which remembers the state
(on or off) of the alarm, trip and, if configured to latch, user-programmable LED
indicators when the relay was last energised from an auxiliary supply. Therefore
these indicators may also illuminate when the auxiliary supply is applied.
If any of these LEDs are on then they should be reset before proceeding with further
testing. If the LEDs successfully reset (the LED goes out), there is no testing required
for that LED because it is known to be operational.
4.2.3.1 Testing the alarm and out of service LEDs
The alarm and out of service LEDs can be tested using the COMMISSION TESTS
menu column. Set cell [0F0D: COMMISSION TESTS, Test Mode] to ‘Enabled’. Check
that the out of service LED illuminates continuously and the alarm LED flashes.
It is not necessary to return cell [0F0D: COMMISSION TESTS, Test Mode] to
‘Disabled’ at this stage because the test mode will be required for later tests.
4.2.3.2 Testing the trip LED
The trip LED can be tested by initiating a manual circuit breaker trip from the relay.
However, the trip LED will operate during the setting checks performed later.
Therefore no further testing of the trip LED is required at this stage.
4.2.3.3 Testing the user-programmable LEDs
To test the user-programmable LEDs set cell [0F10: COMMISSION TESTS, Test LEDs]
to ‘Apply Test’. Check that all 8 LEDs on the right-hand side of the relay illuminate.
4.2.4 Field voltage supply
The relay generates a field voltage of nominally 48V that should be used to energise
the opto-isolated inputs.
Measure the field voltage across terminals 7 and 9 on the terminal block given in
Table 4. Check that the field voltage is within the range 40V to 60V when no load is
connected and that the polarity is correct.
Repeat for terminals 8 and 10.
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