Insulation And Contact Resistance Test Procedure; Inspection And Cleaning Of Circuit Breaker Insulation; Functional Tests; Table 5 Maximum Contact Resistance - Siemens 3AH Series Instructions Manual

Maintenance

Insulation and Contact Resistance Test Procedure

1. Observe safety precaution 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 AC or DC (Table 4) high potentia l test
voltage between a primary conductor of the pole and
ground for one mi nute.
4. If no d isruptive discharge occurs, the insulation system is
satisfactory.
5. After test, g round both ends and the middle of each
vacuum bottle to d issipate any static cha rge.
6. Discon nect the leads to the spring charging motor.
7. Connect a l l points of the secondary disconnect with a
shorting wire. Connect the shorting wire to the h i g h
potential l e a d of t h e high voltage tester, a n d g round the
circuit breaker housing. Starting with zero volts, gradu­
a lly increase the test voltage to 1 500 volts rms, 60 Hz.
Maintain test voltage for one minute.
8. If no d isruptive discharge occurs, the secondary control
insulation level is satisfactory.
9. Disconnect the shorting wire and re-attach the leads to the
spring charging motor.
10. Perform contact resistance tests of the primary contacts.
The resistance should be read between the lower and
upper connection pads (Figure
should not exceed the values l isted in Table 5.
Table 5. Maximu m Contact Resistance
Current Rating
(Amps)
1 200
2000
3000
18).
Contact resista nce
Contact Resistance
(Micro-Ohms)
35
30
30

Inspection and Cleaning of Circuit Breaker Insulation

1. Perform the Spring Discharge Check on the circuit breaker
after all control power is removed. The Spri n g Disch a rg e
Check consists of 1 ) pressing the red Open push button,
2) then pressing the black Close push button, and 3) again
pressing the red Open push button . All of these controls
are on the circuit breaker front panel (Figure 1 ) . Visually
verify the Discharge con d ition of the springs.
2. Remove a ny interphase and outerphase barriers if fur­
nished (applicable for certain types only).
3. Clean ba rriers and post insulators using clean cloth
a n d one of the following solvents:
• Isopropyl or isobutyl alcohol
4. Replace all barriers. Check a l l visible fasteners again
for condition and tightness.
N ote: Do n ot use any cleaning compounds contain­
ing ch lorinated hydrocarbons such as trichlorethylene,
perchlorethylene or carbon tetrachloride.
These compounds will damage the phenylene ether
copolymer m aterial used in th e barriers and other insu­
lation on the circuit breaker.

Functional Tests

Refer to the I nsta l l ation Checklist in the I n stallation Checks
a n d I n itial Functional Tests section of this manual. Func­
tional tests consist of perform ing at least three (3) Manual
Spring Charging Checks a n d three (3) Automatic Spring
Charging Checks. After these tests are complete, and the
springs are fully d ischarged, all fasteners and con nections
a re checked again for tightness and condition.
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