ABB BUE, Руководство по ремонту

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33 1ZSE 5492-129 en, Rev. 6
3. Repairs and adjustments
3.6 Tests of the pressure relay
Tools required:
■
Air pump with pressure gauge (0-250 kPa) and connection to R 1/8” male thread.
■ Screwdriver
■
Megger (500-2 000 V)
1. Insulation test
Remove the cover of the relay housing. Disconnect all incoming wires from the terminals.
Connect terminal NO (identified 61) on the pressure relay block to earth. Terminal C (identi -
fied 62) should be electrified with the megger (500-2000 V for one minute).
Connect the pressure relay housing to earth. Short-circuit the four terminals and apply test
voltage 500-2000 V on them for one minute. Remove the short-circuit from the terminals
and reconnect the incoming wires.
If the pressure relay does not withstand the electrical stress, the pressure relay should be
replaced, see section 3.9 ”Replacement of pressure relay”.
2. Function test
Set the valve handle to the test position as shown on the information plate.
Connect the air pump and the pressure gauge to the test tap on the pressure relay. (Thread
R 1/8”).
Raise the pressure until the pressure relay trips the circuit breakers of the transformer.
Read the pressure on the manometer and check against the pressure stated on the informa-
tion plate. Max. permitted deviation is ±10 %. If the deviation is greater, the pressure relay
should be replaced, see section 3.9 ”Replacement of pressure relay”.
Check that the signal disappears when the pressure is released.
After finishing the check, turn back the valve handle to service position.
Return to section 2.2.