Maintaining Your Unison DR or ER System

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Figure 3: Removing a Unison DR or ER air filter

Cleaning dimming rack air filters

Clean the filter on your dimmer cabinet every six months, more often if your system operates in a dusty environment.

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. The Unison dimmer rack carries only an IP00 protection rating when control or dimmer modules are removed.

Do not remove dimmer modules when vacuuming. Phase voltages inside the rack can be deadly, therefore only qualified technicians should be allowed to remove modules and expose the inside of the dimmer rack.

Open the dimmer rack door. The filter is mounted on the inside of the door, held in on the bottom by a metal clip.
Slide the filter up about 1/2 inch until the filter base clears the top edge of the lip. Pull the base out far enough to clear the retaining lip and slide the filter down and out.
Vacuum or blow dust out of the filter.

Note: You can wash the filter under clear tap water, but it must be completely dry before you reinstall it. Do not use soap or other chemicals to clean the filter.

Slide the top of the filter back into the slot at the top of the door until the base clears the metal retaining lip on the bottom of the door.

Note: When you clean the air filter, you should also check the dimmer air vents for dust. See "Vacuuming Dimming Racks" below.

Let the filter drop back into place and close the door.

Vacuuming Dimming racks

You should inspect your dimming rack when you clean the air filter and vacuum the front of the dimmer modules if necessary.

Open the door and look at the modules’ air vents. If dust is thick enough to hide the paint color, vacuum the front of the modules.
Leave the modules inside the rack. Most dust collects on the dimmer choke vents and grills of the dimmer module.
Use a narrow vacuum cleaner nozzle to vacuum dimmer module air vents. Do not push debris into the modules.
Close the door.

Figure 4: Vacuuming the Unison dimmer modules