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Section 6 – Maintenance
6.0
General Requirements
6.0.1
Periodic Checking
Load break switches should be examined and checked once a year or sooner when conditions require it (such as
numerous operations, polluted atmosphere or overloading of the switch). All switches should annually be opened
and closed 2-5 times in succession, not exceeding their rated duty.
6.0.2
Cleaning
All switches, including insulators and operating arms, should be thoroughly cleaned periodically by wiping with a
clean cloth to prevent accumulations of dust. After cleaning, a light coat of lubrication (non-corrosive, high-tem-
perature grease equivalent to SCH-32 Mobiltemp) should be applied to the contact surfaces. Do not use “cup” or
other grease which may harden upon exposure to air.
6.0.3
Contact Inspection
Check to determine that blades make good contact.
A contact resistance measurement between jaw spade terminal and hinge spade terminals should be taken and
should be between 35-100 micro-ohms. Insure that the blades can be “opened” from jaw casting with a pulling
force of approximately 30-36 pounds measured at a point between the main blades just below the jaw contact as
previously described. If force is above 30-36 pounds, see alignment procedure, 4.11.1.
DANGER
Make sure that all power sources
are deenergized before attempting
any maintenance.
!
BreakMaster Load Interrupter Switch
Inspection and Maintenance:
Operating Mechanism
Inspection Item
Criteria
Inspection Method
Corrective Action (if necessary)
Motor
5000 operations
Check condition
Replace brushes
Tightness of hardware No loose or missing parts
Visual and tightening with
appropriate tools
Tighten or reinstate if necessary
Dust or foreign matter No dust or foreign matter
Visual check
Clean as necessary
Lubrication
Smooth operation and no
excessive wear
Sight and feel
Lubricate very sparingly with
light machine oil
Deformation or exces-
sive wear
No excessive deformation or
wear
Visual and operational
Remove cause and replace parts
Manual operation
Smooth and crisp operation
Manual closing and opening Correct if necessary
Control Circuit Parts
Inspection Item
Criteria
Inspection Method
Corrective Action (if necessary)
Closing and opening
devices including
disconnects
Smooth and correct
operation by control power
Test closing and opening
of the switch twice
Replace any defective device
Wiring
Securely tied in proper place Visual Check
Repair or tie if necessary
Terminals
Tight
Visual Check
Tighten or replace if necessary
