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The burdens imposed by the
for the comparable 60 Hz relays.
given in the following table:
DEVICE UNIT
Target
Seal-In
Target
Seal-In
GEI-83910
50 Hz relays are approximately 90% of those shown
The resistance of the target and seal-in units is
RATING
RES. 25°C
1 A
0.34 Ohms
1 A
0.28 Ohms
0.6A
0.73 Ohms
0.6A
0.72 Ohms
_ _ _
----.:_~
_ _ _ :...:.... _ _ ---------.J
CALCULATIONS OF SEITINGS
It
is
cond it ions.
follows:
not possible to give specific settings for the CLPG12C relay for all
However, a general guide for setting the three units of this relay
TWO-TERMINAL LINE
GO UNIT:
Set for minimum pickup (maximum sensitivity).
Check to ensure pickup for
all si ngl e-phase-to-ground fau lts on the protected 1 i ne with 1 i ne breakers closed
at both terminals.
Use dual polarization where facilities permit.
Gl UNIT:
The preferred pickup setting is the minimum rated pickup value of this
unit.
Do not set higher than 80% of the G2 pickup setting at the remote end of the
line.
t )
G2 UNIT:
Set pickup no higher than 67% of minimum single-phase-to-ground fault
current in the relay with the remote breaker closed.
Lower pickup settings are
permissible,
and
in
most
cases
desirable
for
increased
speed
of
operation.
However, do not set pickup lower than 125% of the Gl pickup setting at the remote
end of the 1 ine.
THREE-TERMINAL LINE
GO UNIT:
Set for minimum pickup (maximum sensitivity).
Check to ensure pickup for
all
si ngle-phase-to-ground faults on the protected 1 i ne with the 1 i ne breakers
closed at all three terminals.
Use dual polarization where facilities permit.
Gl UNIT:
The preferred pickup setting is the minimum rated pickup value of this
unit.
However, when current outfeed can exist for internal faults, an attempt
should be made to set the pickup above the value of outfeeding current at that
terminal.
In any event this unit should not be set higher than 40% of the G2
pickup settings at the two remote terminals.
\i~_~lnI:
Set pickup no higher than 67% of the minimum single-phase-to-ground fault
current in the relay with both
rl~mote
line breakers closed.
Lower pickup settings
are permissible,
and
in most Cilses desirable for increased speed of operation.
However, do not set pickup lowey' than 250% of the Gl pickup settings at the two
remote terminals.
6
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