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DIRECTIONAL UWIT
Current Polarization
b. Adjust the control spring for 0.5 amperes pickup if current polarized or dual
polarized.
Potential Polarization
c. If potential polarized, connect-per Fig. 25 of
l
INSTANTANEOUS UNIT
1. Select the desired range by making the proper connections at the rear of the relay
(see internal connections diagram).
range since it has a higher continuous rating.
2. Set the instantaneous unit to pick up at the desired' current level.
ACCEPTANCE TEST section.
In view of the vital role'of protective relays in the operation of a power system,
it is important that a periodic:test progrma be followed. It is recognized that the
interval between periodic checks will vary depending upon environment, type of relay
and the user's experience with periodic testing.
experience to select the test interval best suited to his individual requirements,-it
is suggested that the points listed below be checked at an interval of fran one to
years.
These tests are intended to ensure that the relays
original settings.
serviced as described in this manual.
TARGET AND SEAL-IN UNIT
Check that the unit picks up at the values shown in
Check that the unit drops out at 25 percent or more
TIME OVERCURRENT UNIT
Perform pickup test as described in the INSTALLATION section for the tap in
1 .
service.
2.
Perform the time tests as described in the INSTALLATION section.
DIRECTIONAL UNIT
Repeat the portion of the installation test for the polarity condition for which
*Indicates Revision
P E R I O D I C C H E C K S A I D R O U T I N E M A I N T E N A N C E
If deviations are encountered, the
.
TEST CONNECTIONS.
( 210 percent).
Whenever possible always select the higher
Until the user has accm'aulated enough
have not deviated fran their
relay must be retested and
Table 11.
of tap value.
19
Ten volts and 0.36
See the
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