Common Tasks
39
Vacuuming Dimmer Modules
As with cleaning the air filters, you should inspect the dimmer module air vents and SCR power cube
inlets every six months and clean if necessary. Clean with greater frequency if your system operates in
a dusty environment.
To vacuum the dimmer module air inlets:
1:
Open the rack door and inspect the air vents on the CEM3 and the air vents and SCR power
cube air inlets on the dimmer modules for any collection of dust or other debris.
2:
If necessary, use a vacuum cleaner and nozzle to remove any visible dust or other accumulated
matter from the front of the modules
without removing them from the rack.
Most dust collects
on the dimmer choke vents and SCR power cube air inlets of the modules (shown below).
3:
Close the rack door when you are finished vacuuming.
WARNING:
To avoid the possibility of electric shock, power must be turned OFF when you
perform this procedure. Before vacuuming dimmer or control modules de-
energize main feed to dimmer rack.and follow appropriate Lockout/Tagout
procedures as described in NFPA Standard 70E. It is important to note that
electrical equipment such as dimmer racks can present an arc flash safety
hazard if improperly serviced. This is due to available large short circuit
currents on the feeders of the equipment. Any work on energized equipment
must comply with OSHA Electrical Safe Working Practices.
Do not remove dimmer modules when vacuuming. Phase voltages inside the
rack can be deadly, and therefore only qualified technicians should be
allowed to remove modules and expose the inside of the dimmer rack.
CAUTION:
Be careful not to push any foreign matter into the module.
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Dimmer choke vent
SCR air inlet
