Electrical - Can I use a 220AC rated temp switch at 12 Volt

Got a problem? Find an answer or at least a guess on how to fix it here. Gearheads and Grease Monkeys step right in!
Post Reply
User avatar
Second Gear
Posts: 762
Joined: Mon Apr 01, 2013 10:38 am

Electrical - Can I use a 220AC rated temp switch at 12 Volt

Post by xbacksideslider »

see attached pdf of dead ebay link

Can I use this type of 220 volt AC bi-metal temperature switch, to switch 12 volts DC?

For my air/water intercooler project I want to switch the coolant fan on at about 100F or thereabouts.

And, of course, all the standard automotive fan switch thermocouples remain open until about 180F at the lowest.

From the ebay ad -

- Bimetal disc thermostat, it can screw on to any metal surface
- Type: N.O. (Normal Open)
- It is open until the surface reaches 45 Celsius degree and then the switch closes. automatically reset
- When the surface cools off about 5 degrees, the switch automatic opens
- Voltage: 110V AC TO 250V AC
- Circuit resistance: 50 Mohm
- Insulation resistance: 100 Mohm
- Withstand voltage: 1500V AC/minute
- Opening-closing durability: 10000 times or more (under rated load)
- General-purpose low cost, compact, large capacity, minute current thermostat
- Application: For Household electric appliances, PC, Microwave ovens, Irons, Refrigerators, Electronic oven, heating unit, coffeepot, water heater, etc.
220volt switch.pdf
(187.98 KiB) Downloaded 644 times

User avatar
Fourth Gear
Posts: 2528
Joined: Fri Sep 12, 2008 12:00 pm

Re: Electrical - Can I use a 220AC rated temp switch at 12 V

Post by Tetge »

I am guessing that the answer is no as AC electronics and DC electronics are generally different. But, why not use a thermal switch that is made for your application, even if it is 180*, and then wire a manual on/off switch into the system so that you can override the sensor and turn on the fan at any point that you wish. Most of the time, you could leave it in automatic mode and it would work and be quieter, etc. When you wanted things cooler, you could turn the fan on manually, and, I suppose with experience, you could run the fan manually a lot if the temps were going to run over 100* all the time. You would have to remember to turn it off if you didn't wire it into the ignition switch controlled circuit.

Second Gear
Posts: 907
Joined: Fri Mar 29, 2013 4:25 pm

Re: Electrical - Can I use a 220AC rated temp switch at 12 V

Post by SonicVenum »

Thishttp://www.summitracing.com/parts/der-16759/overview/ fan controller from Derale adjusts down as low as 150*F. I had one for a while, and the functionality was great, but it wasn't beefy enough to run my Mark VIII electric fan, which draws a lot of amperage. It also has inputs for other methods of turning on/off the fan (an a/c switch), which you can wire to a switch that will allow you to turn on the fan whenever you want.

Post Reply

Return to “General Automotive Troubleshooting”