23
I.B. 8926-1A
Part 10
MAINTENANCE
PREVENTIVE MAINTENANCE
Preventive maintenance should be a program, a
scheduled periodic action that begins with the
installation of the equipment. At that time, specific
manufacturer’s instruction literature should be
consulted, then stored for future reference. Follow-up
maintenance should be at regular intervals, as
frequently as the severity of duty justifies. Time
intervals of one week, or one month, or one year
may be appropriate, depending on the duty. It is also
desirable to establish specific check lists for each
control, as well as a logbook to record the history of
incidents. A supply of renewal parts should be
obtained and stored.
This control equipment is designed to be installed,
operated, and maintained by adequately trained
workmen. These instructions do not cover all details,
variations, or combinations of the equipment, its
storage, delivery, installation,
check-out, safe
operation, or maintenance. Care must be exercised
to comply with local, state, and national regulations,
as well as safety practices, for this class of
equipment.
Authorized personnel may open a unit door of a
motor control center (MCC) while the starter unit is
energized. This is accomplished by defeating the
mechanical interlock between the operating
mechanism and the unit door. A clockwise quarter-
turn of the slotted head screw located above
operating handle will allow the door to open. See
Figure 33.
When servicing and adjusting the electrical
equipment, refer to the applicable drawings covering
the specific motor control center (MCC) and any
other related interconnection drawings. Follow any
instructions, which may be given for each device. A
list of instruction leaflets covering standard
components is shown on the back page of this
manual. Any of these leaflets may be obtained by
contacting your nearest Cutler-Hammer
Representative.
General Guidelines
– The whole purpose of
maintaining electrical equipment can be summarized
in two rules:
a. Keep those portions conducting that are intended
to be conduction.
b. Keep those portions insulated that are intended
to be insulated.
Good conduction requires clean, tight joints, free of
contaminants such as dirt and oxides.
Good insulation requires the absence of carbon
tracking and the absence of contaminants such as
salt and dust that become hydroscopic and provide
an unintended circuit between points of opposite
polarity.
Fig. 33 Defeater Mechanism
CAUTION: Maintenance of control components
requires that all power to these components be
turned OFF
by opening the branch circuit disconnect
means and withdrawing the unit to the detent
position (see Figure 29) or removing the unit entirely
from the MCC.
When units are fully inserted into
the MCC, the line side of each disconnect is
energized. Do not work on fixed units unless the
main disconnect for the MCC is OFF.
When working on portions of a branch circuit remote
from the MCC, lock the disconnect means for that
circuit in the OFF position. To positively lock the
operating mechanism in the OFF position, a metal
Fig. 34 Locking Out a Disconnect
Содержание Freedom 2100 Series
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