Electrical Control Checks; Table 3 Typical Vacuum Interrupter Contact Life Expectancy - Siemens 3AH Series Instructions Manual

Maintenance

Electrical Control Checks

The electrical controls of the circuit breaker should be
checked d u ring inspections to verify a bsence of a ny me­
cha nical damage, and proper operation of the a utomatic
spring charging a n d Close a n d Trip circ u its.
Unless otherwise noted, all of these tests a re performed
without a ny control power applied to the circ u it breaker.
Check of the Wiring and Terminals
1. Physically check all of the circuit breaker wiri ng for evi­
dence of abrasion, cuts, burning or mechanical damage.
2. Check a l l terminals to be certain they are solidly attached
to their respective device.
A
Hazardous voltages and high-speed
mechanical parts.
Will cause death, severe personal injury, or
property damage.
De-energize before working on this equ ipment.
Read instruction m a n u a ls, observe safety in­
structions and limit use to qualified perso nnel.
Automatic Spring Charging Check
(Control Power Required)
Repeat the automatic spring charging check described in
the section entitled Installation Checks a n d I n itial Functional
Tests.
WARNIN G
Table 3. Typical Vacuum Interrupter Contact Life Expectancy
Rated Max. Interrupting Rated
Voltage Class Current
4.76kV 25DMVA 36kA
4.76kV
35DMVA 49kA
8.25kV 5DOMVA 41 kA
1 5kV 5DDMVA 23kA
1 5kV 750MVA 36kA
1 5kV 10DOMVA 48kA
38kV 1 5DDMVA 35kA
4.76kV 31.5kA 31.5kA
40kA
4.76kV 40kA
4.76kV 50kA 50kA
8.25kV 40kA 40kA
1 5 kV 20kA 20kA
1 5kV 25kA 25kA
1 5kV 31.5kA 31.5kA
1 5kV 40kA 40kA
1 5kV 50kA 50kA
38kV 31.5kA 31.5kA
Primary tasks o f this check are:
1.The circuit breaker is energ ized with control power for this
check.
2. E nergize th e control power source.
3. When control power is connected to the circuit breaker,
the closing spring should automatical ly cha rge. Visually
verify that the closing spring is charged.
N ote: A temporary source of control power and test leads
may be requ ired if the control power source has not been
connected to the switchg ear. Wh en control power is con­
n ected to the circuit breaker, the closing spring should
automatically charge.
Curve Number
A
3
c 10
c 8
8 4
A 3
c 9
D 1 3
8
6
7
c
c 11
c 7
A 1
8
5
8 6
c 7
c 1 1
D 1 2
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