Maintenance
Voltage
Interrupting
Continuous current
kV
kA
1,200 A
2,000 A
3,000 A
15.5
20/25
160
105
----
15.5
31.5/40
105
105
95
27.6
20/25
160
105
----
38.0
20/25
160
105
----
38.0
31.5/40
150
105
----
Table 5: Maximum contact resistance (micro-ohms)
Insulation and contact-resistance test
procedure
1. Observe safety precautions listed in the
danger and caution advisories for the
vacuum integrity check tests.
2. Close the circuit breaker. Ground each
pole not under test. Use manual
charging, closing and tripping
procedures.
3. Apply the proper high-potential test
voltage (refer to Table 2: High-potential
test voltages on page 23) between a
primary conductor of the pole and
ground for one minute.
4. If no disruptive discharge occurs, the
insulation system is satisfactory.
5. After test completion, ground both
ends and the middle arc chamber of
the vacuum interrupter to dissipate any
static charges.
6. Disconnect the leads to the spring-
charging motor.
7. Test each individual wire, when they
are connected to the operator 64-pin
plug, connect the high-voltage tester
to a particular pin and ground the
circuit breaker housing. Starting with
zero volts, gradually increase the test
voltage to 1,125 volts, 60 Hz z
(750 volts, 60 Hz on pins A1 and D16
for motor circuit). Maintain test voltage
for one minute.
8. If no disruptive discharge occurs, the
secondary control insulation level is
satisfactory.
9. Disconnect the shorting wire and
reattach the leads to the spring-
charging motor.
10. Perform contact-resistance tests of the
primary contacts using a micro-
ohmmeter. Contact resistance should
not exceed the values listed in Table 5:
Maximum contact resistance (micro-
ohms). The contact resistance is
measure across the phase terminals
(outside terminals of roof bushings).
11. Make a permanent record of all tests
performed.
Inspection and cleaning of circuit
breaker insulation
1. Perform the spring discharge check.
A. De-energize control power.
B. Press red open button on the
operating mechanism.
C. Press black close button on the
operating mechanism.
D. Again press red open button on the
operating mechanism.
E. Verify spring condition indicator
shows DISCHARGED.
F. Verify main contact status indicator
shows OPEN.
2. Remove the phase barriers (if provided)
as shown in Figure 5: Type SDV6
distribution circuit breaker with
interphase barriers and bushing
current transformers installed in
primary compartment on page 17.
3. Clean barriers, post insulators and roof
bushings using clean cloth and
isopropyl alcohol.
4. Reinstall all barriers. Check all visible
fasteners again for condition and
tightness.
31
