Open-Contacts High-Potential Test
1.
Pull down the Manual Operating Handle to open the
recloser contacts.
2
. Ground the recloser head casting, control, and load-
side bushing.
3.
Apply the proper test voltage to the source-side
bushing.
4.
The recloser should withstand the test voltage for 60
seconds.
5.
Ground the source-side bushing.
6.
Apply the proper test voltage to the load-side bushing.
7.
The recloser should withstand the test voltage for 60
seconds.
Test Results
The high-potential withstand tests provide information on
the dielectric condition of the recloser and the integrity of
the vacuum interrupter.
If the recloser passes the closed-contacts test but fails
the open-contacts test, the cause is likely to be a deteri-
oration of the vacuum interrupter. Replace the interrupter
and retest to confirm the repair.
If the recloser fails the closed-contacts test, the cause is
likely to be a diminished electrical clearance, low oil
dielectric strength, or failed insulation. After correcting
the problem, retest to confirm the repair.
Minimum-Trip Current Level Test
The minimum-trip current can be checked by using the
manual closing tool to close the recloser while it is de-
energized and then tripping the recloser with the low-voltage
ac source. Assemble and connect the low-voltage test
portion of the set-up shown in Figure 12 and proceed as
follows:
1.
With the yellow manual operating handle in the
CLOSED position, use the manual closing tool to
close the recloser.
2.
Connect the low-voltage test leads to the recloser
bushings as shown in Figure 12.
3.
Slowly increase the variable autotransformer voltage
from zero, note the ammeter reading when the
recloser trips, and compare to the VXE control’s pro-
grammed minimum-trip value.
Sequence of Operation Test
The operating sequence can be checked by using the
manual closing tool to close the recloser while it is de-
energized and then tripping the recloser with the low-
voltage ac source.
1.
Check the number of programmed fast and delayed
operations by observing the VXE control DIP switch
setting for Operations To Lockout (labeled S2) and
the number of TCC 1 fast operations programmed on
DIP switches labeled S3.
2.
Assemble and connect the low-voltage test portion of
the set-up shown in Figure 12 and proceed as follows:
3.
With the yellow manual operating handle in the
CLOSED position, use the manual closing tool to
close the recloser.
4.
Connect the low-voltage test leads to the recloser
bushings as shown in Figure 12.
5.
Using the customer supplied variable autotrans-
former, apply a test current above the minimum-trip
level to trip the recloser.
6.
Repeat step 5 until the recloser locks out, which is
indicated by the orange control lockout indicator tar-
get on the bottom of the control cabinet.
Test Results
Note the number of fast and delayed operations to lockout
and compare these numbers to the programmed values.
S280-16-1
17
!
SAFETY
FOR LIFE
WARNING:
Hazardous voltage. Never connect
a high voltage source for testing closing coil oper-
ation and a low voltage source for fault current trip
operation, simultaneously. The high- and low-voltage
circuits are not compatible. Failure to comply can result
in death, severe personal injury, and equipment damage.
T233.2
!
Figure 12.
Suggested test diagram for minimum-trip testing.
120 Vac
1
2
Clamp-on
Ammeter
NOTE: Use at
least 2/0 cable
between bushings
Variable
Autotransformer*
(10 A)
600:5
Recloser
BCT on 600:5 Tap
This Test Circuit can
apply over 800 A
to the Recloser
*Customer Supplied.
