GE P741, Technical Manual

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P74x/EN CM/Na7 Commissioning
(CM) 10-12 MiCOM P741, P742, P743
CM
4.2.2.2 Without an IRIG-B signal for Central Unit (P741) or Peripheral Unit (P742/P743)
If the time and date is not being maintained by an IRIG-B signal, ensure that cell
[DATE and TIME, IRIG-B Sync] is set to ‘Disabled’.
Set the date and time to the correct local time and date using cell [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 [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 LED’s are on then they should be reset before proceeding with further testing.
If the LED’s successfully reset (the LED goes out), there is no testing required for that LED
because it is known to be operational.
Note: It is likely that alarms related to the communications channels will not
reset at this stage.
4.2.3.1 Testing the alarm and out of service LEDs
The alarm and out of service LED’s can be tested using the COMMISSION TESTS menu
column. Set cell [COMMISSION TESTS, Test Mode] to ’Out Of Service’ on the P741 then
select at least one zone or ‘50BF Disabled’ on the P742 / P743. Check that the out of service
LED illuminates continuously and the alarm LED flashes.
It is not necessary to return cell [COMMISSION TESTS, Test Mode] to ‘Disabled’ at this
stage because the test mode will be required for later tests.
Out of service LED behaviour for P741xxxxxxxxx5K:
−
If the logic input “All Prot Blocked” is ON, then the ‘Out of Service’ LED is NOT
illuminated because this is an elected operation by the user and can be indicated on
the programmable LEDs if indication is required.
−
If individual zones of protection, or multiple zones, or all zones are switched out of
service via external switches (i.e. using the DDB signals within the PSL), the ‘Out of
Service’ LED remains OFF because this is an operator manual selection. It just
switches for "abnormal" operating conditions rather than for commissioning purposes.
−
When selection of zones in/out of service is achieved via the Commission Test column
of the menu structure in the CU, as soon as the user has the potential to switch zones
in/out of service, then the ‘Out of Service’ LED comes ON but no zone is out of service
until, in the Commission Test column, a zone is selected to be out of service and the
patent is applied.
−
The ‘Out of Service’ LED ON only turns off when the commissioning mode has been
set to “Disabled” AND all zones are selected in service in the Commission Test
column (note: if the user wants to select a zone out of service for operational reasons,
this must be done by the switches and not the setting selection in the commissioning
mode).