Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums > The Basement

Air Compressor Pressure Switch?

(1/3) > >>

W. Mark Hellinger:
I've been looking to source an air compressor pressure switch with a 3 position lever, i.e.:  includes a low pressure shut-down. I'm coming to the conclusion that such a thing might not exist.  Maybe it doesn't exist for good reason, but I can't imagine why not?  However, I've looked and looked and can't find such a thing... and figured if any bank of knowledge would know, it's likely here.

Anyhoo:  My well pump controller has the three positions:  Off, Start, and Auto.  When starting at zero pressure in the system, you gotta hold it in the start position till they system builds 10 lbs. or so, then you can flip the switch to auto... basically a Murphy Switch concept.  Thus the system shuts down in the event of a system rupture or such.  I'm thinking same-same would be excellent for my shop air compressor, but I can't find such a thing.  And of-course one can't use a water pump controller/pressure switch for an air compressor because the water pump switch doesn't have the unloader needed for the air compressor (so the motor isn't starting under a hard load).  If I've gotta do-it-myself, I'll series wire-in a "low pressure resettable pressure switch"... cause I really like the idea of a catastrophic shut-down with the air compressor... but it would be more civilized to have it all in one... if such a thing exists.

Tim McCulloch:

--- Quote from: W. Mark Hellinger on March 12, 2024, 12:13:43 PM ---I've been looking to source an air compressor pressure switch with a 3 position lever, i.e.:  includes a low pressure shut-down. I'm coming to the conclusion that such a thing might not exist.  Maybe it doesn't exist for good reason, but I can't imagine why not?  However, I've looked and looked and can't find such a thing... and figured if any bank of knowledge would know, it's likely here.

Anyhoo:  My well pump controller has the three positions:  Off, Start, and Auto.  When starting at zero pressure in the system, you gotta hold it in the start position till they system builds 10 lbs. or so, then you can flip the switch to auto... basically a Murphy Switch concept.  Thus the system shuts down in the event of a system rupture or such.  I'm thinking same-same would be excellent for my shop air compressor, but I can't find such a thing.  And of-course one can't use a water pump controller/pressure switch for an air compressor because the water pump switch doesn't have the unloader needed for the air compressor (so the motor isn't starting under a hard load).  If I've gotta do-it-myself, I'll series wire-in a "low pressure resettable pressure switch"... cause I really like the idea of a catastrophic shut-down with the air compressor... but it would be more civilized to have it all in one... if such a thing exists.

--- End quote ---

You're wanting a low pressure cut off so your compressor won't run continuously in the event of an air distribution failure?

Consider looking at HVAC refrigerant pressure switches.  You'd need a supporting relay or contactor, possibly.

W. Mark Hellinger:

--- Quote from: Tim McCulloch on March 12, 2024, 01:18:29 PM ---You're wanting a low pressure cut off so your compressor won't run continuously in the event of an air distribution failure?

--- End quote ---
Yes, per exactly Tim.  I.e. (for example):  So I don't walk into the shop first thing in the morning, sniff and go:  "Humm... smells like smoldering oil... why's that???"  Quick look around... go into the room that houses the air compressor:  "Oh, there's your problem... the air compressor is SMOKING... profusely!  Why's that?  Cause the stuff that goes around and around and makes noise is glowing orange... cause it's really hot... cause it's seemingly been running for a long time... oh, and I see the system pressure is ZERO... and its' usual noise when running is notably different... sounds like a rod about ready to exit the crankcase... and discover that's because it is (compressor guts are about ready to seek daylight)... and that's because the compressor is out of oil having discharged that lubrication stuff from the inside to the outside when the seals melted out of it."  Shut the compressor off.  "Oh here's the problem: The pneumatic box stapler that got left plugged-in... it's trigger assembly fell apart and dumped the system air... seemingly sometime last night."  Oh yea, and: The end of month electrical bill was considerably higher... too... adding insult to injury.


--- Quote from: Tim McCulloch on March 12, 2024, 01:18:29 PM ---
Consider looking at HVAC refrigerant pressure switches.  You'd need a supporting relay or contactor, possibly.

--- End quote ---
Will do... thanks for the tip!  Hadn't thought about HVAC stuff... probably cause I have basically zero knowledge/experience with that subject.

Tim McCulloch:

--- Quote from: W. Mark Hellinger on March 12, 2024, 02:08:28 PM ---
Will do... thanks for the tip!  Hadn't thought about HVAC stuff... probably cause I have basically zero knowledge/experience with that subject.

--- End quote ---

The HVAC models may not be in the range you want, but I'd bet the same manufacturers will have a wide selection.

Bill Meeks:
There are also relatively cheap low pressure cut out switches for well water pumps that might be suitable from manufacturers such as Square D. I checked some of these and they are rated for use up to 220 PSI (not to exceed pressure). Search for "Square D low pressure cutoff switch". These require a manual reset when they trip out on low pressure, but that is probably what you want anyway.

My working life (before I did cybersecurity/IT stuff) was maintaining and then teaching industrial process control systems for power plants. If you want a step up into the pro level, consider something like Barksdale pressure switches: https://www.barksdale.com/products/pressure/mechanical-pressure-switches or Static-O-Ring (SOR): https://www.sorinc.com/products-category/pressure-vacuum-switches/. To put these in speaker terms, Square D is Alto and Barksdale or SOR are Meyer  :D.

Navigation

[0] Message Index

[#] Next page

Go to full version