Insulation; External Wiring; Watchdog Contacts; Power Supply - GE P24DM Technical Manual

P24xM
Check that the current transformer shorting switches in the case are wired into the correct circuit. Ensure that,
during withdrawal, they are closed by checking with a continuity tester. The shorting switches are between
terminals 21 and 22, 23 and 24, 25 and 26, and 27 and 28.
5.1.2

INSULATION

Insulation resistance tests are only necessary during commissioning if explicitly requested.
Isolate all wiring from the earth and test the insulation with an electronic or brushless insulation tester at a DC
voltage not exceeding 500 V. Terminals of the same circuits should be temporarily connected together.
The insulation resistance should be greater than 100 MW at 500 V.
On completion of the insulation resistance tests, ensure all external wiring is correctly reconnected to the IED.
5.1.3

EXTERNAL WIRING

Caution:
Check that the external wiring is correct according to the relevant IED and scheme
diagrams. Ensure that phasing/phase rotation appears to be as expected.
5.1.4

WATCHDOG CONTACTS

Using a continuity tester, check that the Watchdog contacts are in the following states:
Terminals
3 - 5
4 - 6
5.1.5

POWER SUPPLY

The IED can accept a nominal DC voltage from 24 V DC to 250 V DC, or a nominal AC voltage from 110 V AC to
240 V AC at 50 Hz or 60 Hz. Ensure that the power supply is within this operating range. The power supply must be
rated at 12 Watts or more.
Warning:
Do not energise the IED or interface unit using the battery charger with the battery
disconnected as this can irreparably damage the power supply circuitry.
Caution:
Energise the IED only if the auxiliary supply is within the specified operating ranges.
If a test block is provided, it may be necessary to link across the front of the test plug
to connect the auxiliary supply to the IED.
5.2

PRODUCT CHECKS WITH THE IED ENERGISED

Warning:
The current and voltage transformer connections must remain isolated from the IED
for these checks. The trip circuit should also remain isolated to prevent accidental
operation of the associated circuit breaker.
P24xM-TM-EN-2.1
De-energised contact
Closed
Open
Chapter 19 - Commissioning Instructions
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