Fan Limit Control Switch Wiring

The controllers have 2 switches.

Fan limit control switch wiring.

Turn off electrical power to the heating system reconnect the fan motor where you previously disconnected it turn on electrical power to the heating system call for heat. Wiring diagram for fan limit switch. The fan limit switch on a heating furnace controls when the furnace blower fan turns on and off. By admin march 14 2018.

If the fan limit switch worked normally continue as follows. Set the building thermostat to call for heat. These combination warm air fan and limit controllers are suitable for various types of forced air heating systems. This control also provides a safety limit that turns off the burner or furnace if temperatures at the furnace are too high.

The first thing you will want to notice is the length of the insert for the control. The other switch turns the fan on and off. Fan limit switches are used on all types of building heating furnaces. The furnace limit switch which will turnoff the burner if the temperature limit is reached is controlled by the two right connections red dots.

Here the furnace limit switch is controlling a line voltage device. Fan limit control installation faqs. One which opens the limit circuit if the plenum temperature exceeds the preset safety limit. The fan or furnace blower motor is controlled by the two left connections green dots.