I needed to replace the controller in my remote io cabinet so I went ahead with this 12v programmable temperature relay. When the internal air temperature gets above 36C I want the vent fan to come on.

Read on for the installation of this WH9002A controller and fan.

Step 1: The Vent Fan.

This 80mm brushless pc fan I secured onto the cabinet lid.

Step 2: Placing the Controller.

Using double sided tape I stuck the controller on the inside of the lid.

Step 3: Placing the Sensor.

The sensor I placed at the top of the lid to measure the hottest temperature.

Step 4: Wiring the Fan.

The positive wire of the fan I connected to the NO contact of the controller relay. The common I wired to the 12v supply terminal.

Step 5: Power Supply.

Using an existing terminal block for 12v electronics, I tapped off for the fan controller.

Step 6: Programming.

The HS is 33C. The D is 3C. Delay and timer are both 0. HC is set to C.

Step 7: Completion!

The fan controller is now operational. I tested the functionality with a hot spoon placed in boiling water. At 36C the fan is on and at 33C it goes off. Perfect!