With the original window unit conversion, a 12kbtu unit that plugged into a standard 120 volt outlet, I used a generic defrost control module. The relay had dual throw contacts, so I wired a light dimmer on the normally open contact for the fan motor. When the unit was defrosting, the dimmer was set so the fan spun really slow. This prevented the fan from freezing to the drain pan and kept indoor heat exchanger from turning into an ice block.
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