GEK-49861
TABLE XVI
OVERCURRENT SUPERVISION ADJUSTMENT
POTENTIOMETER DESIGNATION
ADJUSTMENT FOR PHASE PAIR
P2
P4
P6
AB
BC
CA
b)
Reduce voltage VT until continuity tester indicates that the
main output contacts are closed.
Reduce VT to approximately
80% of this voltage and maintain at this value.
c)
Turn potentiometer P2 clockwise until the continuity tester
indicates that the main output contacts are open.
d)
Alternately raise and lower current IT slightl:f and check
that output contacts are open for values of IT sl1ghtly less,
and closed for values of IT slightly more, than the desired
sensi ti vi ty setting.
{The output contacts should be closed
for values that are 10% higher than the desired sensitivity
setting) .
e)
Change connections to phase pair BC and repeat steps a)
through d) except use potentiometer P4 for adjustment.
f)
Note:
Change connections to phase pair CA and repeat steps a)
through d) except use potentiometer P6 for adjustment.
In
order
to
set
the
sensitivity
of
the
overcurrent
supervision to a value near the low end of the setting range
given in Table IV, it may be necessary to change the relay
restraint setting to a very low value.
If the test circuit
shown in Figure
31
is used in place of the one shown in
Figure 24, this change in the relay restraint setting will
not be necessary.
7.
MOB
Tests (Type
SLY81B
only)
There are two timer adjustments on the "SP" card for setting the
MOB function.
These adjustments are listed in Table XVII.
TABLE XVII
MOB FUNCTION ADJUSTMENT
POTENTIOMETER
TIMER
ADJUSTMENT
60
HZ
RELAY
SO HZ
RELAY
DESIGNATION
FUNCTION
RANGE
FACTORY SETTING
FACTORY SETTING
(MILLISECONDS)
MILLISECONDS
MILLISECONDS
P7
Characteristic
2 -
s
3
3.6
P8
Duration
33
-
67
so
60
The test circuit for checking either of these timer settings is
shown in Figure 27.
The recommended procedure for checking the
"CHARACTERISTIC TIMER" is as follows:
a)
Connect Channel One of the oscilloscope to test point "BIN"
on the "IT" card.
Trigger the oscilloscope from this channel
with positive slope.
24
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