Wiring the Compressor

Twice now, over the course of the past week, we’ve managed to blow the 20 amp spike fuse with the compressor. We’ve triple-chcked our wiring, according to this year’s power distribution diagram. The Spike’s power does go through a 20 amp breaker before it gets to the spike, and the spike is hooked up to a relay. The RC is programmed to run the compressor automatically when the pressure switch, which is wired to a digital input, is released, and turn it off when the switch is triggered.

My first guess is that the spike is bad, especially considering how the plug for the “PWM cable” on the spike itself seemed to be faulty; if I jiggled it a bit, the signal tended to be cut (as in the LED turned off completely, which is only supposed to happen when the fuse blows). We switched out for a different spike, but haven’t really had enough time to see if the problem is fixed. We think it has been, after measuring the current and running it a bit, but I figured to be sure, I’d ask if anyone else can see something we’re not or has had a problem similar.

maybe your digital input is in backwards?

seeing as you switched the spike, it was probably a bad spike. please do inform us if the problem comes up again.

(perhaps that code in your signature is the problem (= )

From the 2007 FRC Pneumatics Manual See page 3

A spike relay must be used to control the power to the compressor using a 20amp breaker, not a fuse.

We have done this in the past, replacing the fuse with a 20amp snap action breaker in the spike module.


Mike (Phalanx) is correct. It is also stated in <R65>:

The fuse on the Spike relay for the air compressor may be replaced with a 20 Amp Snap-Action circuit breaker.

The issue is the inrush current on the Thomas Compressor.

Note that this is the only Spike that can be modified in this manner…



Well, that would do it. We haven’t used any pneumatics in the past three years. That might be how we missed it. Thanks guys.