# Air Compressor Timer



## 69-er (Sep 28, 2007)

I forgot to turn off the circuit breaker to my air compressor last night.  Well, during the night it turned on, and at some point both connecting rods broke.  Since it couldn't build pressure, it ran for who knows how long until I heard it running this morning.

Is there a method or system available to prevent an air compressor running uncontrolled for long periods?  I thought of using a timer that could be set to run for, say, 30 minutes every time the compressor starts and resets when the compressor turns off.  I think that would be long enough since I don't believe I would ever need to operate the compressor any longer, but if it were unattended, short enough to prevent an uncontrolled run time.

I've searched online, but haven't found anything that has a delay longer than 17 minutes.

Any thoughts?

Thanks!

Larry


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## Phatboy (Sep 29, 2007)

How old is your compressor?

All new compressors come with a pressure activated switch.  You plug it in, it goes up to the max operating pressure and shuts off.  Use up some air, get it down to the min operating pressure and it kicks back on.  

Does yours not have a pressure switch, and if not, you should get one.  Asap.  Now that yours has bit the dust, it may be time for an upgrade.  Just be glad that it broke the rods, instead of blow the tank while your standing there.


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## Daryl in Nanoose (Sep 30, 2007)

You could put a switch to controll the outlet that the compressor is pluged into.


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## glennjanie (Sep 30, 2007)

I vote for Logan's pressure control switch on this one. However, the electrical code frowns on using the circut breakers as a switch, so Daryl is correct also.
Glenn


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## 8307c4 (Nov 6, 2007)

Is this an air compressor such as which might be used for pneumatic tools and the like?  That's the only thing I've ever heard called an air compressor, now I am sorry but if you got one that doesn't shut itself down when the tank reaches a certain psi then I suggest you go to Northern Hydraulics and get a real one.

That's the first time I've ever heard of such a compressor running forever, unless you've got an air leak in the lines that stay hooked up, just doesn't sound safe to me.


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## Hack (Nov 8, 2007)

I have my dust collector connected to a timed outlet.  I used a simple rotary timer (60 minute).  I turn it to the desired time I want the collector to run and then turn on the collector.  If I forget to turn it off, it goes off automatically.  I have a similar setup for a fan at the top of my garage.  It's got a thermostat attached that turns it on if the temperature at the top of the garage exceeds 90 degrees, a bypass so I can turn it on no matter what the temperature is, and a timer on the bypass switch so when I forget to turn it off, it goes off automatically.


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## jack3140 (Jan 25, 2008)

assuming you just want to control the power  get a small electronic timer and a 30a 2pole contactor  feed the power thru the contactor and control the contactor with the timer   hope this helps


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## guyod (Jan 25, 2008)

Everyone kinda said it but let me spell it out.. Just wire in for a standard wall switch. but instead of a switch just get a switch/timer you can find at any big box store. they are normally used for bathroom fans/ heaters.


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## ToolGuy (Jan 25, 2008)

It appears everyone is misreading this one. Not that I have a solution or anything, but just to clarify... The compressor is not building up pressure because the connection rod broke. So a switch when it reaches a certain amount of pressure is not what he's asking about. What he's asking about is a timer that resets whenever the motor kicks in (I know, he said when it shuts off, but that was bass ackward), and will shut the motor off if it runs for, say, 30 minutes.


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## inspectorD (Jan 26, 2008)

I think we all have answered something...or nothing,.... 
Let's break it down.
 1. The compressor rods broke and the thing ran forever.
2. He wants it to shut off after he turns it on...without thinking about ...it in 30 minutes.

a pressure control switch will do nothing...there is no pressure being built up with broken rods...thus it will not shut off.

You need a timer. Any department store will carry one which plugs into the outlet, and the compressor plugs into that. You can set it to come on at say 9 am and shut off at 9;30 am every day. Or you can buy a timer like the heat fans in bathrooms and jacuzzis to run for a little and run out. Kind of like ...set it and forget it. 

Good catch Tool Guy,, and to those with all those wonderful ideas. And to anyone who took the time to answer.


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## CraigFL (Jan 27, 2008)

The only thing you need to be sure about with the timer is that it will handle the current for your compressor. So many of these cheap timers won't consistantly switch/carry 15A from a motor start. And if it's 20A or 220V, it will be more difficult to find a heavy duty timer/switcher.

Now if you wanted to be really clever, you would build a timer with a motor starter into a box and attach a pressure switch contol timer circuit --- if the pressure doesn't build to 20psi in 5 minutes, the circuit turns off....


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## inspectorD (Jan 27, 2008)

Now why didn't I think....O" never mind....
Those are great ideas....but I think he's still replacing the connecting rods. 

Hmmmm....Motion sensor compressors....scare the heck out of any unsavory characters trying to lift your stuff. 

This needs to go in the invention post...........


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## triple D (Jan 30, 2008)

I would have to say if you broke your rods, the motor would be big enough to melt a bathroom switch, or a wind up timer. The response with the motor contactor,( in the compressor world, we call this a mag start) would be the only correct help for you. But to help you properly set this up safely and to code we would need to know the volts, amps, and horse pwr. of new pump motor. If you woke up and the thing was running with broken rods, it was either toast to begin with, out of oil,  or you broke a hose or pipe in the night? Anyway i'm guessing 20-30 amp 2pole? pwr. from brkr. into rated disconnect switch, then into mag start, then to compressor. On mag start there is on/off switch. If you can't remember to turn off this switch, it has a low enough current through it that you could bypass this and run through a wind up timer, NOT A PUSH BUTTON 1 5 10 15 MIN. TIMER! But a wind up timer rated for at least 15 amps and 1500 watts and I'm betting 240v for mag coil. Ask more if you need more.


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## dyhunter (Aug 4, 2011)

I too have been wondering about getting a timer on my compressor.  The problem is that if the compressor is running when the timer shuts it off, then the compressor will not bleed the back pressure.  When the power comes back on, the motor is then jammed.  There should be a way to make  something that if the compressor is runnig, the power is left on until the compressor shuts down.


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## Johnboy555 (Aug 8, 2011)

I've been up and down these forums for a while now and I still can't understand why some of these ppl fail to READ the post before they have "THE ANSWER"......

Come on guys please READ first!!

Thank you very much!!  lol


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## Johnboy555 (Aug 8, 2011)

Hey... just a thought... 
How about wiring in a "photo cell"??  It would have to be wired into a relay to handle the amperage probably, but you don't work in the dark do you??


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## infoNS (Mar 7, 2014)

I think this multi function timer should do the trick.  It looks as though you just have to run a few wires, set up your timer schedule on the device, and your have an easy digital timer!  Price point, not bad, especially for the technology used.  Compared to other timers, like Intermatic and Tork, this seems like it would be the best fit. 

Electronic 7 Day Timer Switch|Universal Equipment Timer | Nanospark


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## infoNS (Mar 7, 2014)

I think this multi function timer should do the trick.  It looks as though you just have to run a few wires, set up the timer on the device, and it is ready to go!  Price point, not bad, especially for the technology used.  Compared to other digital timers, like Intermatic and Tork, this seems like it would be the best fit. 

Electronic 7 Day Timer Switch|Universal Equipment Timer | Nanospark


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## infoNS (Mar 7, 2014)

I think this digital timer switch should do the trick.  It looks as though you just have to run a few wires, set up the timers schedule, and it is ready to go!  Price point, not bad, especially for the technology used.  Compared to other digital timers, like Intermatic and Tork, this seems like it would be the best fit. 

Electronic 7 Day Timer Switch|Universal Equipment Timer | Nanospark


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## nealtw (Mar 7, 2014)

infoNS said:


> I think this digital timer switch should do the trick.  It looks as though you just have to run a few wires, set up the timers schedule, and it is ready to go!  Price point, not bad, especially for the technology used.  Compared to other digital timers, like Intermatic and Tork, this seems like it would be the best fit.
> 
> Electronic 7 Day Timer Switch|Universal Equipment Timer | Nanospark



Welcome aboard,, this question really old, A bit of waiste of time.


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## dyhunter (Mar 8, 2014)

The problem with a timer on your compressor is that if the timer shuts it down, it will not release the 'charge' pressure.  You know the hiss you hear when it turns off normally.  If this pressure is not released, the moter most likely will not be able to start back up.


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