44
1MRS 755539
Feeder Protection Relay
Operator’s Manual - ANSI Version
REF 610
4.7.2.
Testing of the ground-fault protection
When calculating the current to be injected into the
ground-fault
current energizing
input, the calculation should be done on the basis of the following:
the rated current, 0.2 A, 1 A or 5 A, of the relay energizing input to be tested
This gives the current to be injected during the test as follows:
injected current (A) = 2.5 x 51N x Rated current of energizing input
To perform the test, inject the current in the ground-fault current energizing input.
The output contacts, to which the trip signal has been routed from the ground-fault
protection element, should be activated on the expiration of the set operate time of
element 51N.
