Detaching And Installing The Plug-In Unit - ABB REF 610 Operator's Manual

REF 610
3.4.2.
36
Feeder Protection Relay
Operator's Manual - ANSI Version
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Fig. 3.4.1.-1 Checking the order number of the relay

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:
Order number of the relay case
Order number of the plug-in unit
REF610B55HCHP XX
REF610B55HCNR XX
1MRS 755539