TM 5-3895-374-24-1
Units
WARNING: Units must be de-energized before
maintenance is performed M-11. Maintenance of
control units should be performed at ]east
annually or more frequently, depending on
service
conditions
and
your
established
maintenance policy. The procedure outlined
below should be followed at the time of
installation to locate and tighten any connections
which may have loosened during shipment and
handling If the unit is to be removed from the
motor control center for maintenance, begin with
Procedure M-17. If maintenance is to be
performed with the unit installed, begin with
Procedure M-12.
NOTE The back of each unit door contains
pertinent information for that specific unit. This
information includes connection diagrams and
selection tables for thermal units.
Control Unit Lockout
M-12
The control unit lockout is a standard feature on
every plug-on unit This allows the unit to be
padlocked in a test position with the unit
disengaged
from
the
vertical
bus
bars
Maintenance can be performed on all the unit
parts which are normally energized through the
plug-on assembly. All wiring to the unit can
remain connected for circuit testing.
M-13
Move the operating mechanism to the OFF
position.
M-14
Loosen the knurled thumb screws on the door
and open the door. (Screws are captive ). Check
for live circuits using a voltmeter and de-
energize any sources of voltage found.
(page 3-134)
