Alstom MiCOM P54 Series, Technical Manual, Page: 945 / 1024

Installation P54x/EN IN/La4
MiCOM P543, P544, P545 & P546 (IN) 15-5
IN
5. RELAY MOUNTING
MiCOM relays are dispatched either individually or as part of a panel/rack assembly.
Individual relays are normally supplied with an outline diagram showing the dimensions for
panel cutouts and hole centers. This information can also be found in the product
publication.
Secondary front covers can also be supplied as an option item to prevent unauthorized
changing of settings and alarm status. For MiCOM relays housed in 80TE cases, the
relevant part number is GN0038 001.
The design of the relay is such that the fixing holes in the mounting flanges are only
accessible when the access covers are open and hidden from sight when the covers are
closed.
If a P991 or MMLG test block is to be included, it is recommended that, when viewed from
the front, it be positioned on the right-hand side of the relay (or relays) with which it is
associated. This minimizes the wiring between the relay and test block, and allows the
correct test block to be easily identified during commissioning and maintenance tests.
P0146ENc
Figure 1 Location of battery isolation strip
If it is necessary to test correct relay operation during the installation, the battery isolation
strip can be removed but should be replaced if commissioning of the scheme is not
imminent. The red tab of the isolation strip can be seen protruding from the positive side of
the battery compartment when the lower access cover is open. To remove the isolation
strip, pull the red tab whilst lightly pressing the battery to prevent it falling out of the
compartment. When replacing the battery isolation strip, ensure that the strip is refitted as
shown in Figure 1, i.e. with the strip behind the battery with the red tab protruding.
5.1 Rack mounting
The P54x may be specifically-ordered for rack mounting. The model number must have an
“N” selection as the 10th digit, example:
P54Xxxxxx N xxxxx
The relay case has mounting flanges factory-fitted, with dimensions in accordance with
IEC 60297, to fit directly into a standard 483 mm (19”) rack system. The relay occupies the
full width of the rack, with a tier height of 177 mm (4U, equivalent to 7”).