Count Restraint
The count restraint feature prevents erroneous counts of
overcurrents interrupted by downline protective devices
by blocking the counting operation as long as a mini-
mum of 0.5 A of uninterrupted line current flows through
the sectionalizer.
The operation of the count restraint can be verified by
superimposing an interruptible overcurrent on a constant
minimum line current. The sectionalizer will not count or
open on the interruption of the overcurrent as long as
the minimum line current is not interrupted. To check the
count restraint feature, proceed as follows:
1.
Jumper the ground actuating current resistor with a
short lead to disable the ground sensing circuit.
2.
Jumper terminals P and D together.
3.
Check that the sectionalizer control is set for one-
count-to-open.
4.
Close the sectionalizer by operating the close pullring
the required number of times.
5.
With the test circuit connected to phase A of the sec-
tionalizer and S1 closed (to simulate a constant load
current of approximately 6 A), hold S2 closed and raise
the test current to slightly above the appropriate values
shown in Column B of Table 8. Hold S2 closed for at
least three seconds
6.
Release S2 to simulate a downline device clearing the
overcurrent. The sectionalizer
should not
open verify-
ing the operation of the count restraint feature.
7.
Open S1 and again close and adjust S2 to simulate a
backup device clearing the fault. This time the section-
alizer should count the overcurrent interruption and
open.
8.
Remove the jumper from terminals P and D.
Voltage Restraint
When energized at 120 Vac, the voltage charging board
provides fast charging times for the trip energy storage
capacitors. It also acts as a voltage restraint; the sectional-
izer will not count an overcurrent interruption of the protec-
tive device unless the voltage at the control is also inter-
rupted. To check the voltage restraint feature, proceed as
follows:
1.
Jumper the ground actuating resistor with a short lead
to disable the ground sensing circuit.
2.
Jumper terminals P and D together.
3.
Program the sectionalizer for one-count-to-open.
4.
Close the sectionalizer.
5.
Connect 120 Vac across pins B and D of the 120 Vac
input receptacle.
6.
With the test circuit connected to Phase A of the sec-
tionalizer and S1 open, Close S2 and raise the current
slightly above the appropriate value shown in Column
B of Table 8. Hold S2 closed for at least three sec-
onds.
7.
Release S2 to simulate a downline device clearing the
overcurrent. The sectionalizer
should not
open.
8.
Disconnect the 120 Vac from the input receptacle.
9.
Again close and release S2. The sectionalizer
should
open.
10.
Remove the jumper from terminals P and D.
Number of Counts-to-Open
The number of counts-to-open can be verified by inter-
rupting, the preset number of times, an overcurrent
through the sectionalizer. For example, with the control
set for three counts, the sectionalizer will open upon the
third overcurrent interruption. Proceed as follows:
1.
Jumper the ground actuating current resistor with a
short lead to disable the ground sensing circuit.
2.
Jumper terminals P and D together.
3.
Program the sectionalizer for three counts-to-open by
setting the COUNTS-TO-OPEN SELECTOR switch to
3.
4.
Close the sectionalizer by operating the close pullring
the required number of times.
5.
With the test circuit connected to phase A of the sec-
tionalizer and S1 open, close S2 and raise the test cur-
rent to slightly above the appropriate value shown in
Column B of Table 8. Hold S2 closed for at least three
seconds.
6.
Open and close S2 a number of times. The sectionaliz-
er should open upon the third opening of S2.
7.
To verify the two-counts-to-open setting, set the
COUNTS-TO-OPEN SELECTOR switch to
2
and
repeat steps 3 through 5. The sectionalizer should
open upon the second opening of S2.
8.
Remove the jumper from terminals P and D.
Type GV and GW Installation Instructions
18
