High-Potential Withstand Testing - Cooper Power Systems NOVA 15 Installation And Operation Instruction Manual

Type NOVA Three-Phase, Microprocessor-Controlled Recloser Installation and Operation Instructions

High-Potential Withstand Testing

The following equipment is required for this test:
High-voltage test set – Must be capable of supplying suit-
able voltages for determining the dielectric withstand capa-
bility of the recloser. Sensitive circuit breakers should be
included to prevent damage in the event of a flashover.
Note: Test results for NOVA reclosers equipped with the
internal voltage sensing option will be influenced by the
source-to-ground connected sensing resistor, especially
if DC high-potential testing is performed.
WARNING: Hazardous voltage. The switchgear
(apparatus and control) and high-voltage trans-
former must be in a test cage or similar protected area
to prevent accidental contact with the high-voltage
parts.
Solidly ground all equipment. Failure to comply can
result in death, severe personal injury, and equipment
damage.
CAUTION: Radiation. At voltages up to the
specified test voltages, the radiation emitted by
the vacuum interrupter is negligible. However, above
these voltages, radiation injurious to personnel can be
emitted. See Service Information S280-90-1, Vacuum
Interrupter Withstand Test Voltage Ratings Information
for further information.
Use the following procedures to perform high-potential
withstand tests at 75% of the rated low-frequency with-
stand voltage for 60 seconds. Refer to Table 11 for test
voltages and Figure 25 for test connection diagrams.
Test results for NOVA reclosers equipped with the internal
voltage sensing option will be influenced by the source-to-
ground connected sensing resistor.
TABLE 11
Type NOVA Recloser Withstand Test Voltage Ratings Information
75% of Rated Low-Frequency
Withstand Voltage
(1 minute dry) (kV rms)
Description
NOVA-15
NOVA-27
NOVA-38
* Approximately 0.53 mA additional leakage current per phase
with internal voltage sensors.
† Approximately 0.32 mA additional leakage current per phase
with internal voltage sensors.
** Approximately 0.37 mA additional leakage current per phase
with internal voltage sensors.
24
T221.5
G109.2
AC DC
37.5 53.0*
45.0 63.6†
52.5 74.2**
TEST 1
PHASE TO GROUND
5 6
ac
ac
3 4
2
1
TEST 3
OPEN CONTACT
5 6
ac
3 4
2
1
Figure 25.
Connection diagrams for high-potential withstand
testing.
Test 1
1. Close the recloser contacts.
2. Ground the recloser.
3. Connect terminals 2, 4, and 6 (see Figure 10) together.
4. Apply proper test voltage (see Table 11) to terminals 2,
4, and 6.
5. The recloser should withstand the test voltage for 60
seconds.
Test 2
1. Close the recloser contacts.
2. Ground the recloser.
3. Ground terminal 2 and terminal 6.
4. Apply proper test voltage to terminal 3.
5. The recloser should withstand the test voltage for 60
seconds.
TEST 2
PHASE TO PHASE
5 6
3
4
2
1
OPEN CONTACT
5 6
ac
3 4
2
1