36
1MRS 755539
Feeder Protection Relay
Operator’s Manual - ANSI Version
REF 610
Fig. 3.4.1.-1
Checking the order number of the relay
3.4.2.
Detaching and installing the plug-in unit
Prior to detaching the plug-in unit from the case, the auxiliary voltage must be
disconnected. To detach the plug-in unit, lift the lower handle until the spring-loaded
locks on both sides of the handle are released and the unit is pushed about 6 mm out
of the case. This will separate the connectors and you can easily pull the unit out of
the case.
The relay features an automatic short-circuit mechanism in the current transformer
(CT) connector. Therefore, detaching the plug-in unit will not open the secondary
circuit of the CT which otherwise could cause dangerously high voltages.
Signal connectors will be left open when the plug-in unit is detached.
Fig. 3.4.2.-1
Detaching the plug-in unit from the case
Note!
Before fitting a relay plug-in unit into a relay case, check that the unit and the case
have the same order number. The order number of the case is printed on the bottom
plate inside the case. However, if a substitute plug-in unit has to be used instead of
the original unit, ensure that at least the first ten characters in the order numbers of
the case and the plug-in unit are identical, as in the following example:
a
OrderNo_a
y
Order number of the relay case
REF610B55H
CHP XX
Order number of the plug-in unit
REF610B55H
CNR XX
Det
aching_a
