Air Compressor status

The air compressor is 95% running. It will fire up and cycle properly right now, however, it does not yet respect quiet hours.
There’s a sign on it briefly describing what to do to turn it on and off. Please be sure to follow the directions as written. I hope to have it fully working by Monday, at which point it should be self-sufficient.
The loud noise it makes at the end of the cycle is expected, and will be addressed once I make it to the hardware store.

If anyone’s curious, the old contacts welded together, preventing it from cycling properly. Also, it kicks on at 100 P.S.I. and back off at 160 P.S.I. You can see the current pressure on intweb.

Thank you all for your patience. This is something I’ve been looking forward to doing for a while, but never did because I was doing “serious” work.

I do hope the bleed off exhaust is connected to the rubber chicken, or one of the children’s siren whistles.#

The steam whistle?. :flushed:

As tempting as that is, no. Sorry.

Anyways, the (sadly whistle-less) air compressor is fully functional now. It obeys quiet hours, so you shouldn’t have to do anything to it.

I’ll be tidying up the wiring and getting a proper circuit board in the coming days, but, functionally, it’s 100%. Also to do is muffle the head pressure release valve, but that also does not impede functionality.

If you notice anything amiss, you can e-mail broken about it. Also, you can see its current pressure on intweb (without even needing to log in)!


huh… I guess google groups doesn’t support .gif animations…

Crap. The relay burnt up. I found some solid state relays and will hook them up in a day or two. It was going so well…

Why the hell did the relay burn up? It should have lasted years if a decent quality and sized appropriately. How much current is being swiched? 240V 30A ?


Did you have a capacitor on it?

I might have an extra heavy duty contactor for decent sized ac units.

I wonder if the inrush current may be much more than the normal draw under load.

I think Kevin’s AC Compressor contactor idea is a good one. Not only is an AC contactor designed to turn a massive motor on and off (dealing with transients and inrush and whatnot) it is also a common item that is at least somewhat standardized and would be easy to replace in the future. We got about 5 years out of the contactor that came with our AC system when we replaced it in 2013. That’s a reasonable life. It’s not at all unusual to have 240V / 50A getting thrown around. AC turns the condensor fan on and off all the time, too.

If I were in town, I’d offer to get one.

And if you were wondering how to drive the 24VDC coil of a typical HVAC contactor…

Boost converter + another one of those ST switches I gave you.


I will look for my box tomorrow and let you know. I bought a 5 pack of heavy duty ones along with capacitors super cheap on amazon with prime. I use them quite a bit for stuff and have found them mainly in 24v however I have come across 12v in the past.

Hey, so I feel like a complete idiot. The breaker had tripped on the 220V line to the air compressor. It’s back working.

Dumb question? Why’d the breaker trip? Is it getting old and feeble?
I wonder what affect the replaced dying contactor had on that breaker.