22
BreakMaster Load Interrupter Switch
These contacts do not tarnish like copper, but they should be “wiped” clean occasionally, especially if the switch has
not been operated for some time. This can be done by opening and closing the switch several times in succession.
6.0.4
Insulators
It is necessary that the insulators surfaces be kept clean. This is absolutely essential, particularly when the switches
are located where cement dust, metallic dust, salt spray, acid fumes and other unfavorable environmental conditions
exist. Alcohol cleaner or a light detergent is recommended for cleaning the insulator parts. Make absolutely sure that
proper ventilation and other precautions are taken when using any chemical cleaner. Discard and replace any
insulators showing signs of tracking.
6.0.5
Insulation Check
When making an annual check, all insulation should be carefully examined for tracking. Special attention must be
given to areas where the conductor passes through an insulator or lays near a barrier. Examine the surface for
cracks or streaked discoloration. When tracking is found, the insulation involved must be replaced. In such a case,
contact your local GE sales office for replacement parts.
6.0.6
Bus and Conductor (Switch Blade) Check
Inspect the buses and connections carefully every year for evidence of overheating or damage. It is desirable to
measure the resistance to ground and between phases of the insulation of buses and connections with a meter (or
use a megger of proper voltage. A record should be kept of this reading. Weakening of the insulation from one mainte-
nance period to the next can be recognized from the recorded readings. At recording time, the record should include
the temperature, the humidity, and the date.
6.0.7
Chain Drive
The chain drive assembly connects the stored energy mechanism to the operating handle on the front of the
housing. It consists of a length of roller type chain fastened in a loop by two adjustable turnbuckles with locking
nuts. Make sure turnbuckles and locking nuts are tight. No adjustments are necessary.
6.0.8
Operating Shaft
The operating shaft connects the stored energy mechanism to the switch operating arms. The shaft is integral with
the switch assembly and is bearing mounted. Light lubricant applied to bearing surfaces will insure
trouble free operation. No adjustments are necessary.
6.0.9
Pushrods
Each main blade of the switch is connected to the throw arms or the main operating shaft by an insulated pushrod.
These pushrods should be examined during each normal maintenance procedure for signs of damage to either
end. If a damaged pushrod is encountered, replacement parts are needed.
6.0.10
Stored Energy Mechanism
The stored energy mechanism consists of a housing with a one piece crank sprocket assembly supported by bearings
and a spring assembly.
The sprocket assembly is chain driven by means of a handle on the front of the housing. As the handle is moved
upward, the spring assembly is charged. As the crank sprocket assembly passes over dead center, the spring takes over
and drives the switch to the closed position. The unit is factory adjusted and should need no adjustment in the field.
Check to make sure the latches rotate freely up and down by using finger pressure on the rollers. Check for loose
bearing bolts.
WARNING
Do not attempt to grind blades with powdered emery or other abrasives.
Such practice inevitably results in poor contact and overheating.
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