How to wire Air Compressor's spike relay?

My team is doing a last-second rush on our robot, and we’re stuck on our air compressor’s spike relay wiring. Any tips on how we can do this?

I’m probably the last person to answer this question, so my answer carries all the authority of “something I read on the Internet”. But I do have a source: on page 16 states, “The Solenoid Breakout
● Has 8 solenoid outputs.
● Completely eliminates the need for Spikes for pneumatics.
● Can drive 12 Volts at up to 0.75 Amps per output.”

So you might not need to use a Spike.

Not quite…

You do have to use a Spike relay for the compressor. The compressor is rated around 20A, so you will need to hook it up to the Spike. GND and 12V are the input lines that go directly to the power distribution board. Use 18AWG wire (preferably 14AWG to handle the compressor startup better). Plug in a 20A breaker into the power distro board, and take out the yellow fuse and replace it with a 20A breaker. Trust me, you’ll thank me for that tip.

The compressor hooks directly to the M- and M+ leads just the way you would think. Red goes to M+, Black goes to M-…

Hook a PWM cable to the Spike and plug it into the sidecar. Take note of where you plug it into so you can use it in your programming. There are outputs on the sidecar labeled as Relay. The black end of the PWM cable goes where it says (-) and the red goes on the center, and the white goes where it says A.

If you try to run the compressor with the way mr_yes described, you will burn something up, and it won’t be the compressor (yea, it will be something much worse so do not wire it that way).

If you needed to know how to hook up the compressor, you probably want to know how it shuts on and off.

The pressure switch included in the kit needs to be wired to another PWM cable. Cut off the male end with the metal prongs sticking out, and peel back the white and black wires. Hook those to the screw terminals of the pressure switch. White one on one side, black one on the other side, then plug it into a Digital I/O port.

Then you’ll have to program it. I know how to, but I don’t have the software loaded on my computer, so someone else will have to chip in on that if your programmers don’t know how.

Thanks RyanN for the clarification. We’re all students here.

thats fine and all but which wire is signal and which is power, and which port on the pressure switch do they need to go on.

The pressure switch is just a switch, nothing special. Black wire on one side, white wire on the other, then plug it into one of the Digital I/O ports on the side car, where the black goes to (-), and the white goes to SIG. In reality, it doesn’t matter which way the wire goes since you’re just completing a circuit, but that’s the way you’re supposed to plug it in.

The PWM cable (3 wire White, Red, Black) wire is the signal wire for both the Spike and for the pressure switch. The Spike and pressure switch do not connect directly. By the rules, the compressor must be controlled by the cRIO.

To make it easy for later, plug the Spike into the Relay 1 port, and the Pressure Switch into the Digital I/O 1 port.

That’s the side car below. You can see the Digital I/O and Relay on the right side.](

One last note, please slow down your typing. I know you’re in a hurry to get it all working, but it actually takes less time to write your question down clearly, then for me to decipher what you are asking. I’m not even sure what power and signal you’re trying to figure out, so I’m assuming the Spike. Be more descriptive.

Here’s a quick sketch I made. The green wires are PWM cables. Breakers should be 20A.

Drawing1.pdf (403 KB)

Drawing1.pdf (403 KB)

Drawing1.pdf (403 KB)

Team 358 has done a great job of explaining it here:

Our team is stuck with the same problem. We have wired it following the directions given above, but still when we turn the power on the compressor does not turn on. Is the light on the spike relay supposed to be red? Does it have to be programmed to make the compressor come on or should it come on directly from the power?

Assuming it is wired correctly you now need to program the cRIO to read the pressure switch and depending on the state of the pressure switch you either turn on or off the Spike relay control bit. Sorry I do not have any programing code for you.

A few pointers:
For the pressure switch which is nothing more then a SPST switch that is OPEN when the pressure is low and then CLOSES when the pressure is high. Just two states for the pressure switch, on or off.

On the Spike, be careful as the Spike has FOUR possible output configurations that is decoded from the TWO digital signals that come into the Spike from the Digital Sidecar. It is best that you look up the technical specs for the Spike to find out the decoding of the digital signals, as it very well presented in the technical specs.

Just a side note: This is my first year as a mentor :slight_smile:

TEM 1514 - We are rookies this year (obviously). My programmer is working to figure it out, he is using Labview and trying to just use an example they have. Thanks for the input.


The Nason Pressure Switch OPENS when the pressure is above 125psi and CLOSES when it drops below ~95psi. See page 3 of the FRC 2010 Pneumatics Manual. It must be installed on the high pressure side of the regulator.

The robot inspector may check that the pressure relief valve works by using a clip-wire to short the Pressure Switch, effectively closing it. This should turn on the compressor. The relief valve must be installed directly on the compressor this year <R77>. The inspector will run the compressor up to no more than 135psi expecting that the relief valve will operate at ~130psi.

In LabVIEW the compressor just needs compressor code in

Wiring is shown in the LabVIEW example: