Can a 12 VDC 35A rated switch be used in a 24V 30A application

Question

As the title says, I would like to use a DC toggle switch rated for 12VDC 35A for my application which is 24VDC with a max current of 25-30A (to be decided).

The switch is a car switch as in photo below.

Will it be safe to use this switch for the application?

Thanks in advance!

Dave

No. You're using it at double the rated voltage; it could arc, and that little light on it will certainly not survive. — Hearth, May 03 '17 at 04:11
Simple solution, just use the switch to drive a relay. That'll work just fine. — alphasierra, May 03 '17 at 06:34

alphasierra · Answer 1 · 2017-05-03T04:19:03.283

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Maybe? It might work, it might not. I definitely wouldn't call it safe. Depends on the quality and construction. It won't be guaranteed to open the circuit at double the rated operating voltage. In a worst case you'll end up with arcing, which is much more difficult to quench for a DC source than it is for an AC source.

Additionally the LED in that switch might get unhappy if it's meant to be supplied with 12V. The best answer is to get one and test it yourself.

edited May 03 '17 at 04:19

answered May 03 '17 at 04:10

alphasierra

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There shouldn't be arcing because the switch will be engaged/disengaged when current is almost zero. Current is controlled via a driver circuit. – Dave May 03 '17 at 06:00

score 1 · Accepted Answer · answered May 03 '17 at 06:28

There are three thing to consider 1. Max Current, 2. Voltage Rating, 3. LED

Max Current Since the max current is 30A and the switch is rated 35A you can safely use the switch in respect of the current
Voltage Rating As mention by others, this may lead to arc, the switch is designed to for 12V operation and their specification like number of times the switch can be ON/OFF (wit load) will be based on 12V, so if the switch is used above the rated voltage the number of cycle is going to reduce, since you had mentioned the switching is going to be used at almost zero current, may be you can safely use it for 24V
LED this will draw more current when used with 24V, assuming it draws 5ma @12V, now it's going to draw 10ma @24V, it may withstand the current but it will glow more brighter more heat and have lesser life

score 0 · Answer 3 · answered May 03 '17 at 05:00

Yes you can, but not directly. Use a relay. Use the switch for turning on a low coil current relay that has a switching spec that exceeds your needs. Even if you power it via 24 V, due to the much lower current, it should last significantly longer.

The light, if an led and if it has an independent pin connection for it, can be adjusted with an appropriate resistor.

Can a 12 VDC 35A rated switch be used in a 24V 30A application

3 Answers3