Flex-a-lite 31163 Variable Speed Control Module with Threaded Temperature Sensor
The Flex-a-lite variable speed control module is an adjustable fan controller that can be set to have your fans come on at any temperature between 160-240 fahrenheit. When fans come on with temperature, they are activated at 60 per cent run using a soft start feature, which greatly reduces startup amperage. As the temperature rises about 10 degrees, the controller gradually increases fan speeds up to 100 per cent.