CR194 Two-High Vacuum Limitamp® Control
While pulling on the h igh-voltage door, lift up on the
defeater bracket as shown in Figure 48 to allow the
high-voltage door to open.
Defeating the high-voltage door inter
lock leaves the power fuses & contactor connected
to the bus. The bus power must stay removed with
the h igh-voltage door i n terlock defeated.
Lift defeater bracket while pulling
To close the high-voltage door with the isolation
switch handle in the "on" position, the procedure
must be done in reverse order, making sure to rein
stall the door interlock defeater locking bolt.
MAINTENANCE & SERVICING
Before performing any inspection,
maintenance or servicing on the equipment all
power must be removed from the equipment and
all load-connected rotating equipment must have
come to a complete stop.
Mechanical Operation Check
Begin any inspection, maintenance and servicing rou
tine by first performing all the checks in the "Mechani
cal Operation Check" section, which is part of the "In
stallation" section of this instruction. This includes:
Isolation Switch Handle to Contactor
Handle and Isolation Switch Operation
High-Voltage Door Safety I n terlock
Control Power Interlock (CPI)
Test Power Interlock (TPI)
Vacuum Interrupter Integrity Test
Then perform the "Vacuum Interrupter I ntegrity
Test", which is a part of the " Installation" section of
Complete maintenance and adjustment instructions
for the high-voltage con tactor are presented in GEH-
5306. Refer to that instruction for all problems of ser
vicing and adjusting the contactor and to the proper
renewal parts bulletin for renewal parts for the
Contactor tip life depends on the severi ty of the ser
vice, but in any case, it is recommended that the
contactor tip wear be checked at l east once a year, or
i n very high duty cycle situations, after every 250,000
Under no circumstances should th e
isolation switch be inspected or adjusted with
power applied to the main bus.
The quick-make, quick-break isolation switch assembly
is adj usted and tested at the factory and under n ormal
circumstances does not n eed adj ustment. However, if
conditions require, the switch can be adj usted in the
field by fol lowing the steps below.