GE Industrial Solutions Evolution Switchboards - Manuel (Page 37)

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3377
W WAARRN NIIN NG G:: De-energize this equipment before
performing any work.
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To obtain the best service from this switchboard, establish a periodic maintenance schedule. At a minimum, perform an
annual check and overall maintenance procedure for the switchboard devices and all connections. Equipment subject to
highly repetitive operation may require more frequent maintenance.
Keep a permanent record of all maintenance work. Include a list of periodic checks and tests, the date they were made, the
condition of the equipment, and any repairs or adjustments performed. Maintenance employees should follow all
recognized safety practices, such as those in the National Electrical Code, the Canadian Electrical Code, and in company
and other safety regulations.
For specific information about the maintenance of devices, such as circuit breakers, relays, and meters, refer to the separate
manuals provided with each device.
Observe the following important points:
• Periodically inspect the switchboard while under load to determine if there is any indication of overheating. If
overheating or any other unsatisfactory condition is found, completely de-energize the switchboard and investigate.
Look particularly for loose bolts and connections or overloading. Remove any accumulation of dirt or other foreign
matter in the enclosure. Do not touch live parts while the switchboard is energized.
• Plated parts may become dark over a period of time because of oxidation. Do not remove this discoloration, as that will
reduce the thickness of the plating.
• Retighten lugs and joints to eliminate possible heating points. Transmission of vibrations through the building structure
and conduits to the switchboard may loosen lugs and joints. Turning the load off and on causes expansion and
contraction between lugs and cables, which tends to loosen the lugs.
• Do not open sealed breakers or trip units, as this may disturb the calibration. Return such units to the factory for any
replacement required.
• Switchboard enclosures equipped with filters are recommended to be inspected at least once a year.
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Switchboards are designed for installation where the average ambient temperature does not exceed 40° C (104° F). For
higher temperatures, derating is required. The conductor temperatures within the enclosure may be as high as 80° C (176°
F). Some parts of the breakers, switches, and fuses may run even hotter. It is recommended that thermal-magnetic molded-
case breakers in switchboards not be loaded in excess of 80% of the rating when the load will continue for three hours or
more, even with ambient-compensated breakers.
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Normally, the overcurrent protective device on the circuit will prevent any electrical damage except at the actual point of
the short circuit. Make a thorough inspection of the entire system after any large fault current to insure that there has been
no mechanical damage to conductors, insulation, or equipment.
In addition, the individual overcurrent protective device or devices that performed the short-circuit interruption must be
inspected for possible arcing damage to the contacts, arc chutes, and insulation. Do not open sealed devices such as
breaker trip units. If there is any possibility that sealed units may have been damaged, they should be replaced. For
additional details on the particular device, refer to the applicable instruction manual provided with the device.
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Some organic insulating materials carbonize when subjected to the heat of an electrical arc and lose their insulating
properties. Any insulation found to be carbon-tracked must be replaced before applying power.