Primary Circuit Resistance Check; Mechanism Check; 6-9.1 Closure Test; T" Contact Wipe Indicator - Eaton W-VAC Series Instructions For Installation, Operation And Maintenance

Instruction Book
Page 42
Figure 6-6 "T" contact wipe indicator.
Close the Breaker
Blue Contact Spring
Figure 6-7 Wipe indicaton.

6-8 PRIMARY CIRCUIT RESISTANCE CHECK

Since the main contacts are inside the vacuum cham-
ber, they remain clean and require no maintenance at
any time. Unlike most typical circuit breaker designs, W-
VAC, W-VACR and W-VACW breakers do not have slid-
ing contacts at the moving stem either. Instead they use
a highly reliable and unique flexible clamp design that
eliminated the need for lubrication and inspection for
wear.
If desired, the DC resistance of the primary circuit may
be measured as follows: close the breaker, pass at least
100 amps DC current through the breaker. With the low
resistance instrument, measure resistance across the
studs on the breaker side of the disconnect for each
pole. The resistance should not exceed the values
shown in Table 6.2.

6-9 MECHANISM CHECK

Make a careful visual inspection of the mechanism for
any loose parts such as bolts, nuts, pins and rings.
Check for excessive wear or damage to the breaker
components. Operate the breaker several times manu-
ally and electrically. Check the closing and opening
times to verify that they are in accordance with the limits
in Table 5.1.
6-9.1 CLOSURE™ TEST
Introduction: The CloSure
effective means to determine and monitor the ability of the
mechanism to close the breaker contacts fully. It provides
a quantitative measure of the extra energy available in
terms of over travel in inches to close the breaker contacts
to their full extent. It may be used periodically to monitor
the health of the mechanism.
At times, circuit breakers are called upon to operate
MOC switches (mechanism operated control switches)
that place extra load upon the closing mechanism of the
circuit breaker. If this load is excessive, it can prevent
Table 6.2 Typical Resistance Measurements
Rated
Continuous
Current
(amperes)
630
800
1250
1600
2000
2500
3150
TM
Test is a simple yet extremely
Resistance
(microohms)
46
39
39
26
26
20
10
IB131009EN