Service Information; Service Requirements; Frequency Of Inspection; High-Potential Withstand Tests - Eaton Cooper Power NOVA NX-STS Installation And Operation Instruction Manual

Service information

Service requirements

The NOVA NX-STS recloser has been designed with a
minimum mechanical life of 10,000 operations. The NOVA
NX-STS recloser requires minimum routine inspection to
check for physical damage and verify proper operation.
It should not be necessary to access the mechanism of
the NOVA NX-STS recloser.

Frequency of inspection

Because these reclosers are applied under widely varying
operating and climatic conditions, service intervals are
best determined by the user based on actual operating
experience. However, solid-insulated, vacuum-interrupting
reclosers should be inspected every 10 years.

High-potential withstand tests

NOVA NX-STS reclosers are carefully tested and adjusted
at the factory to operate according to the published data.
Each recloser leaves the factory ready for installation, but
to ensure there was no damage during transportation,
Eaton recommends high-potential withstand tests before
installation.
To verify the dielectric integrity of the recloser, the following
tests and equipment are recommended:
High-voltage test set—must be capable of supplying
suitable voltages for determining the dielectric withstand
capability of the recloser. Sensitive circuit breakers should
be included to prevent damage in the event of a flashover.
Test results for NOVA NX-STS reclosers equipped
N ote:
with voltage-sensing options may be influenced by
the sensing resistor, especially if DC high-potential
testing is performed.
HAZARDOUS VOLTAGE. THE SWITCHGEAR (APPARATUS AND
CONTROL) AND HIGH-VOLTAGE TRANSFORMER 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.
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.
WARNING
CAUTION
INSTALLATION AND OPERATION INSTRUCTIONS MN280103EN March 2023 www.eaton.com
Use the following procedures to perform high-potential
withstand tests at 75% of the rated low-frequency
withstand voltage for 60 seconds. See Table 8 for test
voltages and Figure 16 for test connection diagrams.
Table 8 . NOVA NX-STS recloser withstand test voltage
ratings information
75% of rated low-frequency withstand voltage
(1 minute dry) (kV rms)
Description AC
NOVA NX-STS 15 37.5
NOVA NX-STS 27 45.0
NOVA NX-STS 38 52.5
Approximately 0.53 mA additional leakage current per phase with
a
voltage sensors.
Approximately 0.32 mA additional leakage current per phase with
b
voltage sensors.
Approximately 0.37 mA additional leakage current per phase with
c
voltage sensors.
Test results for NOVA NX-STS reclosers equipped with
voltage-sensing options may be influenced by the sensing
resistor, especially if DC high-potential testing is performed.
The following tests should be applied to the NOVA NX-STS
recloser system:
Test 1
1. Close the recloser contacts.
2. Ground the recloser.
3. Connect terminals 2, 4, and 6 (see Figure 16) together.
4. Apply proper test voltage (see Table 8) to terminals 2, 4,
and 6.
5. The recloser should withstand the test voltage for
60 seconds.
Service information
DC
53.0
a
63.6
b
74.2
c
17