can we do it?

Hi guys

is it legal to attach the compressor’s electricity cable to the pressure switch instead of using the code?


Team Artemis #3083

Hi May,

The pressure switch is not built to withstand the currents needed to power the compressor, and at least from that perspective it is not possible to connect it that way.

It may also be illegal.

if you need help programming it in let us know…


No. Aside from the legal issues (see <R78>), you’ll also likely blow the switch with that much current running through.

It is against the rules, however, I’m not sure I agree with the notion that its likely to break the switch. We’ve used a setup such as this in a system without an RC or cRIO and achieved expected behavior, though its worth noting that we may well have been operating outside of the switch’s specifications, and shortening its life.

As others have said, it’s against the rules and will likely blow out the switch. Check out page 5 here (it is the catalog page for the switch provided in the KoP):

The switch is rated at 5A, 30V DC. Go above that, and you will burn it out sooner or later (given how these things go… mostly like on the field, in the finals :p).

Don’t forget that the compressor is an inductive load. Simply turning it on and off with a contact switch will result in arcing at the switch which will eventually destroy the switch (and create lots of EMI in the process) unless a suitable snubbing circuit is employed to dissipate the energy in the motor inductance.

The switch probably can’t handle the currents anyways as described by eagle33199. And it’s illegal as described by Billfred.

Sometimes it is very nice to have a hardware solution to a simple problem, though, isn’t it…


I probably should not post this, but…

The pressure switch for a well pump, available at the local hardware store. It’s the same switch that is used on shop air compressors to cycle them.

Definitely NOT FRC legal!

Yea, definitely not FRC legal, but it is a creative solution for other projects.

I did something similar on our old cart. I used the old pressure switch and connected it to a simple automotive relay rated at 30A to run the compressor. It worked well, but I like your solution much better. It looks so cool.