Air Compressor Zero Pressure Safety Cutoff Switch

sam am I

sam am I

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I have a small compressed air setup in my garage where I have two drops to regulators, hose reels etc., etc. where both drops come down from a ceiling run that runs from on side of garage to the other. Two compressors are "T'd" into the system run yada yada.

I leave the system charged (150PSI) for the most part and yesterday while is was out for a bit, one of the crap pile fittings blew open, both compressors ran about 4 hours straight.......Feel lucky I didn't burn one up, geeesh.

Click image for larger version Name: 20180916_152854.jpg Views: 1 Size: 254.1 KB ID: 10655357

If I was on vacation or something, of course I'd shut it down before i left however, being in and out and using it often, I leave it up for daily'ish use.......

If this EVER happens again (odds are low BUT) I would like a "inline safety pressure sensing switch power cutoff relay" (ISPSSPCR......New name here) setup that is armed to cut the power off to the compressors if it detects a sudden drop to zero'ish (fitting or whatever fails) PSI's in the main run (where I install it)......Anyone got a line on something like this? If not, I'm making one!!!
 
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Grub54891

Grub54891

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Interesting. Never thought of something like that. Or how about a timer of sorts, If the compressor takes 10 min to fill the tank, set it for 20 min. If it hits that time limit, it shuts off the compressor. The timer could re-set after every cycle, and manually re-set after the 20 min run?
 
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Redfred1

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With the motor running that long; it seems like the thermal overload would trip!
 
sam am I

sam am I

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Grub54891 said:
Interesting. Never thought of something like that. Or how about a timer of sorts, If the compressor takes 10 min to fill the tank, set it for 20 min. If it hits that time limit, it shuts off the compressor. The timer could re-set after every cycle, and manually re-set after the 20 min run?
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Was thinking that too...Hmmm
 
sam am I

sam am I

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Scott Danforth said:
Look up flow fuse

Like this one https://m.grainger.com/mobile/produc...QaAvOlEALw_wcB

Its designed to shut off system if there is a high flow discharge
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Called the guy who sold me my setup this afternoon, told him what happened and I wanted and he is getting these I think, he wasn't sure what they were called BUT, these are the ticket!! Going to see him tomorrow after fishing....thx Scott.


I don't do any sand blasting or such, some air tools so CFM isn't too critical..........I assume by the design, might casue some reduction but, how much I wonder..........Going to need it on the outputs of each compressor as they join the main overhead feed line. Maybe I can deal with it....Might be able to oversize them with fittings, not sure, they're primarily made for the drops

Hoseguard-example.png
 
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sam am I

sam am I

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Redfred1 said:
With the motor running that long; it seems like the thermal overload would trip!
Click to expand...

Me too but, garage was cool enough I guess. Both compressors even heated the garage (one'ish car garage) up a bit but, they were just hummming away like a 4 hrs straight run was nothing. I felt them both, they were a bit warm, no doubt but, not as hot as I thought they'd be. One is a Husky other is a Dewalt
 
Scott Danforth

Scott Danforth

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the blow out of the plastic fittings and aluminum tube is why I run black pipe for my compressor setup. a friend ran PVC, and it exploded one winter.

the only problem with black pipe is if you want to expand the system, it takes a bit more work.
 
sam am I

sam am I

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Scott Danforth said:
the blow out of the plastic fittings and aluminum tube is why I run black pipe for my compressor setup. a friend ran PVC, and it exploded one winter.

the only problem with black pipe is if you want to expand the system, it takes a bit more work.
Click to expand...

The rep for this stuff called me up after seeing that pic of the blow out and said they went to all alum on all their stuff.

See "PPS1 UN" superceeds mine now I guess

That specific coupler that blew, is only plastic on the blue nuts though the and main body/housing are all alum....hmmmm, not sure, however they/he won't admit that that was an issue though.

"Steve,

This is the worst blow I have seen or have heard of in the four years I have been with Prevost. The reason for all aluminum fittings now was that customers were putting the resin fittings in an outside environment and the UV was causing failures. Plus we went all in at Prevost actually manufacturing the fittings ourselves at a Prevost location in Italy.

I have a Compressor repair customer locally out of the Sandpoint area, that can look at your compressor if needed for repairs. Let me know?

I just relocated to the Northwest area and are still learning my customers in the territory. I am living in the CDA area.

Best regards,"



Looks to me as if the paint let loose, the locking finger took the paint off even.......All the rest of their fittings I bought and used are 100% alum, just that one had plastic nuts........Go figure. Oh yeah PVC is a BIG no no, **** will kill ya. Pex is okay though, won't shatter like PVC.

This stuff is super cool stuff though, my smaller setup went up in like and hour. Super fast to install.....Cost a bit though.



View attachment 2017 PPS1 Price List-compressed.pdf
 
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Redfred1

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Scott Danforth said:
the blow out of the plastic fittings and aluminum tube is why I run black pipe for my compressor setup. a friend ran PVC, and it exploded one winter.

the only problem with black pipe is if you want to expand the system, it takes a bit more work.
Click to expand...

Agree about the PVC. I just ran 1/2" rubber hose. Thought pipe might cause condensation. Do have a filter on it too.
 
bigdee

bigdee

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You may be over thinking this. I have seen small compressors run continuously in industry. No air pressure =no load.
 
sam am I

sam am I

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bigdee said:
You may be over thinking this. I have seen small compressors run continuously in industry. No air pressure =no load.
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Overthink something? Me? Never!! :D

But seriously......

Overthinking why they never burnt up or overthinking auto shutting them off?

True that and that's a valid point as that (no load) is perhaps exactly why they never burnt up but, none the less, I still don't think it is a bad idea to shut them off in the event something lets loose.

Running 4 hours (this time and sure, hindsight is always 20/20) because of a BS unforeseen failure seems a senseless thing to allow if they can be simply auto shut off (mechanically or electrically) in the event it or something similar (earth quake, mouse chew, daughter crashes into drop, asteroid strike, guy with happy sawsall) ever happens again.........If it happens again.:facepalm:
 
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sam am I

sam am I

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This is alum pipe Mike but, yes, if I were going to use Pex, I certainly would use metal fitting and crimp rings.
 
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