Areva MiCOM P225, Technical Manual

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Maintenance P225/EN CM/B11
MiCOM P225 Page 7/18
4. EXCHANGING THE RELAY
The case and the rear terminal blocks have been designed to facilitate removal of the relay
without having to disconnect the scheme wiring.
BEFORE CARRYING OUT ANY WORK ON THE EQUIPMENT, THE USER
SHOULD BE FAMILIAR WITH THE CONTENTS OF THE "HANDLING
AND SAFETY" SECTION.
The method is to replace the withdrawable part, but it may be necessary to replace the
complete relay (with the case):
.
4.1 Remove the withdrawable part
To remove the withdrawable part, lift the upper flap on the front panel to reveal a slot in the
centre towards the top. Using a screwdriver (approx. 3 mm cross-section) insert it in the hole
in the middle of the slot then move the screwdriver from right to left. This moves a cam which
has the effect of moving the withdrawable part of the MiCOM relay a few centimetres.
Lift the lower flap on the front panel. Proceed as above. The withdrawable part can now be
easily removed from the case.
Upper flap
Lower flap
P0432ENa
Before replacing the withdrawable part in the case, reset the 2 opposing cams.
N. B.: - MiCOM P225 relays have integral current transformer shorting
switches which will close when the withdrawable part is removed.
- In case of fuse-contactor controlled by a voltage loss coil, do not
remove the withdrawable part if the contactor is closed. In fact,
removing the withdrawable part will break the power circuit for the
voltage loss coil, causing the opening of the contactor.