Do You Leave Your Air Compressor On?

[George Clark]

Attached are photos of a failure of a combination regulator, filter and water trap in my shop air system. Fortunately, I was in the shop when it failed. It sounded like a shotgun blast when it let go. This was an ARO unit that I installed new. The line pressure had never exceeded the rated pressure of the unit. All four of the locking lugs on the regulator body failed.

The point of my post is not to degrade ARO, parts fail, but to encourage you shut your compressors off when you leave the shop. Had I been away from the shop with the compressor on it would have run continuously until the compressor seized (bad) or things got so hot that the shop caught on fire (really bad).

I had a similar failure about 20 years ago when an air hose fitting failed on my relatively new compressor. I was at home but away from the shop. My wife mentioned that the compressor had been running for a long time. When I went to investigate the compressor was still running but extremly hot. When things cooled the pump was seized and required a complete overhaul at a cost that almost exceeded the cost new. Lesson learned.

George

[Rob Damon]

Not sure if it is the same, but I recieved a recall notice of one that looks similar to that a few months back due to failure. I-R sent me a replacement one free of charge, even though it was several years old and beyond warranty.

I always turn my air compressor off and close the ball valve at the tank and relieve the pressure in the hose. I have not piped the shop yet.

With an 80 gallon tank at 155 psi, I can normally go for days without having to run it, so it does not make sense to leave it on unless I know I will be using it continuously and the pressure has dropped to under 90 psi on the tank.

Considering it can pump out 27 scfm, the idea of a hose busting and blowing out that much air continuously, doesn't seem like a pleasent experience.

Rob

[Gordon Eyre]

Never leave it on but do leave it under pressure (about 120).

[Chris Padilla]

My compressor is on a 24-hour mechanical timer...it is basically on 12 hours and off for the other 12. I hate it when it kicks on at 2 am and I have to change undies....

[Curt Harms]

If you had a fire and had copper or plastic lines. Sweated joints could melt, separate and what was a fire is now an inferno. I don't know if that could happen but I sure wouldn't want to find out, either.

[Bruce Page]

Never leave it on but do leave it under pressure (about 120).

Like Gordon, I shut my off - most of the time...

[Perry Holbrook]

I installed a contactor on my compressor. The coil is wired thru the light switch for the shop. Compressor can't run unless I'm working in the shop with the lights on.

Perry

[Rod Sheridan]

Like Perry, mine has a lighted switch in two locations (garage and basement shop) so I only run it when I'm using it.

I also drain it after using it.

Regards, Rod.

[Thomas Bank]

Never leave it on but do leave it under pressure (about 120).

Same here. Shut off compressor and close the ball valve to the air piping. I've heard too many stories similar to this about something springing a leak and the compressor running until it didn't...

[Bruce Wrenn]

Always plugged in and on, but all air lines are disconnected. When I need air, I need air. Seldom does a metal part fail, but rubber / plastic has been known to do so. My built in regulator, if set below it's maximum, leaks air. Always has and most likely always will, so I leave it at the max. Compressor has been plugged in since it arrived in 1986. Drain moisture regularly though.

[Chip Lindley]

I leave the compressor breaker on, but the ball valve turned off, and the pressure switch off until I need air. The ball valve is between tank and regulator, so, that leaves only the tank to spring a leak and deplete it's air supply if the worst happens. I disconnect the hose to relieve pressure, and so it will coil up in a decent manner. Air hoses under pressure are "alive!" and have a mind of their own!

[Van Huskey]

Not since I saw the thread 3-4 moths ago about the compressor that caught on fire.

[David Hostetler]

Nope. My compressor stays off until I need it. I can wait a couple of minutes for the thing to charge up...

EVEN IF I had the electrical to spare to dedicate a circuit to it, I would still unplug it when I left the shop. I am sort of paranoid about compressors...

[Callan Campbell]

Commerical settings WILL leave their units unattended, and the power on, and it's just the little FRL's like the one you showed, that can wipe out a nice unit in not much time all. We almost lost 2 compressors at work for this very reason, we came back in after a weekend, and don't know how long they were running[super hot in the room they're located in, and we won't even mention the heat of the pumps]:eek:. We lost the plastic bowl of a filter unit at an oil pump that's mounted for bulk oil pumping.
I try to never leave the throw switch "on" for my 2 stage unit unless I'm actually there using it. Just one less thing to worry about;)

[Luther Oswalt]

I have a large vertical tank compressor which I leave on all the time ... But, I always shut the air off at the tank so there is no pressure in the feed lines. I have done this for about 20 or so years without any problems what so ever. To my knowledge there are no plastic parts that could fail ... however, since I cannot spend the time in the shop I once did, I think I will change my methods and start killing the power to compressor motor! This means that I will be pulling the disconect to shut it off. Funny ... this unit was wired per the Compressor Mfg. and the codes at the time ... maybe me and thousands more were just Lucky, Hmmmmm!
Leo

[George Clark]

I think those who close a ball valve at the tank that isolates the compressor and tank from the rest of the air plumbing have taken care 99+% of the potential problems. I do this and shut the power off to the compressor because its easy to do on my compressor. It has on on/off switch on the box that houses the magnetic switch. I guess it's sort of like wearing belt and suspenders.:D

George

[Curt Harms]

My compressor is on a 24-hour mechanical timer...it is basically on 12 hours and off for the other 12. I hate it when it kicks on at 2 am and I have to change undies....

Or worse yet, kicks on at 2 a.m. and wakes SWMBO, leaving her in a foul mood.

[Callan Campbell]

I have a large vertical tank compressor which I leave on all the time ... But, I always shut the air off at the tank so there is no pressure in the feed lines. I have done this for about 20 or so years without any problems what so ever. To my knowledge there are no plastic parts that could fail ... however, since I cannot spend the time in the shop I once did, I think I will change my methods and start killing the power to compressor motor! This means that I will be pulling the disconect to shut it off. Funny ... this unit was wired per the Compressor Mfg. and the codes at the time ... maybe me and thousands more were just Lucky, Hmmmmm!
Leo
I hear what you're saying. I do Both at my house, shut off the power, and always turn the 3/4" ball valve off, isolating the tank from the lines since I know I have a tiny leak all the way out in my garage[the seperate garage is plumbed underground from my basement shop]. At where I work however, just shutting the outlet valves at the 2 tanks would have prevented losing all that air over the weekend from the plastic bowl failure of the air filter. No one does it, however.........:confused:

[Rob Damon]

Just thinking. The commercial air compressors in large shops generally have motors that are rated for continous duty, so if it did spring a leak and run continously, it would be no big deal.

I believe the 7-1/2hp motor on mine is also rated for continous duty, so in theory, I could just leave it on and the system open, but I don't.

Rob

[Thomas Bank]

The other thing for me is that it may be a week or more before I use air the next time. So turning off power makes sense. If I had a business use and was using it daily I'd likely leave it on - perhaps shutting it off over the weekends.

[Callan Campbell]

Just thinking. The commercial air compressors in large shops generally have motors that are rated for continous duty, so if it did spring a leak and run continously, it would be no big deal.

I believe the 7-1/2hp motor on mine is also rated for continous duty, so in theory, I could just leave it on and the system open, but I don't.

Rob Not quite, most air pumps that are running on conventional oil as their lube are rated LESS than continous, 80/20 duty cycle being a norm. You really don't want to find out the hard way if the pump side can handle a wide open load from a blown part by running all night with no one to shut off the system if needed. Hard on the motor, hard on the pump/compressor, and of course really hard on the wallet if either or both suffer damage as a result. The newer assemblies for a commercial setting might brag about using synthetic oil for a continous duty cycle, but there are lots of older compressors running that haven't been built, or upgraded to meet this claim.

[Dan Andrews]

I never leave my compressors on on purpose. However I have a tendancy to forget by the end of the day that I had turned mine on earlier. When I started reading this thread, it reminded me that I had left mine on today, and I went out and shut it off. I need to wire a small red light to be on whenever either of my 2 compressors are on.

[Rob Lindquist]

I wired in a solenoid to shut the supply from the tank when the power was turned of, so the air doesn't leak out while it is off. Then when I come back and turn it on it is always full and not leaked down from leaving a slightly leaky air nozzle or other tool plugged into the air.

I almost lost a shop I was renting when a head gasket blew on the pump, and it ran until everything melted down. Arrived just in time to put out the fire that must have just started. Now power goes off every time.

[Steve Kohn]

I installed a contactor on my compressor. The coil is wired thru the light switch for the shop. Compressor can't run unless I'm working in the shop with the lights on.

Perry

I use a similiar approach. I have a relay in line with the dedicated 220V circuit for the compressor. The relay is only activated when the lights are on. Since I always shut off the lights when I leave the shop, the compressor can't turn on.

Of course when I turn on the lights and the compressor starts it scares the heck out of me.

[Chris Padilla]

Looks like I'll be adding to my own list (not LOMLs):

Wire in a light switch for the compressor to make turning it off easier (my compressor is mounted up near the ceiling :) )

Put in a ball valve to kill the pressure in the lines and isolate the compressor from them.

Oh, and LOML Is a HEAVY sleeper...I'm the light one. :(

[Erik Christensen]

i have my 220v/2 stage unit on a solenoid with the solenoid powered by a switch in the same dual box as my shop lights. If I don't need air I leave it off but when leaving the shop I always hit both switches down on my way out the door.

[Chuck Gallup]

I installed a contactor on my compressor. The coil is wired thru the light switch for the shop. Compressor can't run unless I'm working in the shop with the lights on.

Perry
Most excellent tip!

[Perry Holbrook]

Actually, in addition to the contactor, I installed a solenoid operated valve in the compressor outlet as well. Double protection. My compressor is installed outside and not all that easy to get to, if there were a problem I wouldn't necessarily notice so I took extra precaution.

Perry

[Josiah Bartlett]

I have a compressor rated for continuous duty (Quincy QR-25 series), so I'm not worried about overheating, but I do disconnect the motor, shut the ball valve off to the tank, and burp the tank drain to clear out condensate. I don't ever blow the tank down, though, unless I'm going to work on the piping. My compressor has an oil pressure unloader for in case the lubrication fails, and I have a breaker on the motor rated to shut it down if the motor locks up.

[Jim Davenport]

Being old, and somewhat forgetful.
I try to make things simple. I have a two stage IR verticle.
Every day when I finish in the shop, I drain the tank, close the ball valve, shut off the pressure switch, and unplug the unit.
The tank holds pressure for weeks, So when I work in the shop, there's no wait for the presssure to build.

[Chris Parks]

I never leave it on but I installed an electrical dump valve for the condensate that is run by a timer. If the dogs go ballistic during the night I know I have left the power on to the valve once again. It keeps them amused as it is timed to go off every couple of hours for 10 seconds.

[Curt Harms]

I agree with leaving the tank pressurized. I installed 2 ball valves, one at the tank outlet and one at the moisture drain on the end of an 8" nipple. The nipple moves the valve out from the center of the tank and makes the valve accessible. Also, if I forget to drain the moisture for a few days the nipple has to fill up before there's water sitting in the tank. I don't know about air compressor tanks but repeated pressurizing-depressurizing cycles fatigues aircraft pressure vessels.

[Jim Underwood]

I try not to leave mine on, or even plugged in anymore. I'm inclined to wire it up to the lights like some other folks...

I came back in the shop after a week of absence once, and I tried turning on the compressor, only to find it had tripped a breaker. I flipped the breaker only to have it trip again. At that point I realized that the piston and rod were in pieces on the ground...

I'm just glad all I needed was a new piston, cylinder, teflon ring and rod. :cool:

[Greg Roberts]

Based on what was mentioned here, I just had my electrician hook up a relay to my shop lights, and now my compressor will shut off when I turn out the lights to leave my shop. Great idea, and it works great.

My compressor is located in a shed behind my shop, access only from outside. I have both a 110v and a 220v outlet for compressors out there. My electrician installed a three-pole relay so both outlets are switched.

I asked him to make sure the contacts were rated for continuous duty, and to get the very best one he could.

I hear a humming sound when the relay is on. Should I be concerned at all about something overheating and causing a fire with the relay?

Greg

[Jeremy Brant]

I've become a lot more careful about shutting the balve valve on the outlet line. With that shut, I don't worry about whether or not I hit the switch. I had the gage glass on the IR filter/regulator cup blow out due to a bad o-ring while everyone was out of the house one day. Came back several hours later to the compressor running. The compressor is rated for continuous duty (Eaton), but on conventional oil it was very hot and there was a some oily smoke in the garage. I shut it down, and once it cooled down I immediately changed the oil as it was very dark. Compressor ran as normal, so figured I was ok at that point. Turns out I overtightened the screws on the gage glass putting it back together, and a couple months later it failed again during the night due to a gage glass screw stripping out. Woke up in the morning and heard the compressor running and air escaping. Changed the oil again, and eliminated the gage glass on the cup (plugged the screw holes with bolts and RTV). So far so good now, but I do make shutting the valve a higher priority at the end of the day.

[Tom Hamilton]

I installed a timer on my compressor so that it comes on at 8AM and shuts off at 7PM. I have a little bleed so in the morning when the power kicks in the compressor runs for a minute or two. During the day it may cycle once or twice.

I run the air through 3/8 rubber air lines about 30 feet to get it to the lathe.

Best regards, Tom, in Douglasville, with air always nearby.

[Zach England]

I leave mine on, as I found out at midnight last night.

[Glenn Ebel]

I was wondering how often you guys drain your compressors.

[Jim Becker]

I was wondering how often you guys drain your compressors.

I have an IR auto-drain installed on my compressor and it periodically purges and moisture automagically. I only turn off my compressor when I go on vacation or something like that.

BTW, this is a thread from 2010, but certainly is relevant. :)

[David Freed]

I leave mine on, but shut off the supply to the lines now.

I have a Campbell Hausfeld "Iron Force" compressor that I bought about 10 years ago. When it was about 2 years old, I let the crankcase get low on oil. It blew a hose in the night, ran until the rod seized on the crank, then burned the belt off. The next morning, I opened the door to a shop full of rubber smoke with the motor purring away with no load.

I took the compressor apart and found it was aluminum rods on a steel crank and no rod bearings. I heated the rods with a torch to un-seize them. I sprayed brake cleaner on/in them while hand turning the crank and then used ether to finish cleaning them.

I put some light oil on it and turned it for a few minutes, cleaned it with ether again, then put Lucas hub oil on it and turned it several minutes. I put it back together and filled it with Lucas hub oil. It's been running fine ever since.

I have 2 semi truck a/c condensers plumbed between the compressor and the tank. I got them free because they have pin holes in them and wouldn't hold an a/c charge. I haven't got any water out of the tank drain since I installed them a few years ago.

I really like the idea of hooking the compressor to the lights.