How do you code the compressor?

[Racer26]

I'm not suggesting to take the cRIO out of the loop, but why is it forbidden to have cRIO->Spike->Pressure Switch (its NC, so this works)->Compressor.

In 2003 this is how we wired it till we got to competition and told to change.

I don't understand why this configuration has always been disallowed... Its functionally identical, and there is no possibility for code to screw up.

[Alan Anderson]

Originally Posted by 1075guy

I'm not suggesting to take the cRIO out of the loop, but why is it forbidden to have cRIO->Spike->Pressure Switch (its NC, so this works)->Compressor.

The Nason pressure switch is rated for only 5 amps, nowhere near the current required by the compressor.

[Racer26]

Originally Posted by Alan Anderson

The Nason pressure switch is rated for only 5 amps, nowhere near the current required by the compressor.

That makes sense. Interesting that it worked for us though... guess it would dramatically shorten the lifespan of the switch / leave you open to risks of the switch welding itself or something.

I've seen things like that happen before. On my race car I have a switch on the radiator fans. The switch is rated for 10A (the biggest switch I could find without going online to a specialty supplier), and the fans pull 20-40A. Switch works, but on 2 instances has ceased to function. I thought about replacing it with an old automotive relay or something, but never got around to it. We hadn't realized what happened at first until I thought of the current draw of the motors, and the rating on the switch.

[Omar]

It's a SAFTY issue.

When the field control system shuts down the competition, it will shut down everything including the compressor
When the robot is disabled, all OUTPUTS are disabled including the compressor.

Don’t want a compressor kicking on and pressurizing a line and possible kicking unexpectedly>

Omar

[Racer26]

Omar, with the system I described, FMS will still be able to shut it down, it just takes the cRIO out of the Overpressure-ShutDown condition.

Alan's answer about the 5A rating on the NASON switch was the part I didn't know about, and now it all makes sense to me.