A safety breaker that shuts off after a device is running for a determined amount of time.

Here is the potential problem. I have a home garage type air compressor, something like 20 gallon, 1 or 2 HP, 220 volt in a two car garage. I have pipes routed all around and 4 outlets with hoses. If I’m away and a hose blows it will run for hours or days. This type isn’t designed to run for hours and even if it was, it would consume a ton of kwh. There are a half dozen other malfunctions that could make this thing run and if it ran long enough it would self destruct and be a fire hazard.

YES, I know I could unplug it every day but it’s a convenience thing. Everything ELSE in our lives is designed for convenience.

So for my new device, you plug it in and then plug your device into it. If your device runs for 20 minutes it trips. If it is a normal day and your device runs for 5 minutes, eight times in an hour, nothing happens. A timer starts when it runs and the timer goes to zero when it stops. How hard could that be? I have searched and searched and even embarrassed myself by calling an electrical supply house and describing it. Where are those people who want to invent things?

Seems like a very specific need which is why it doesn't exist yet. I'm guessing there are compressors out there that come with safety switches built in that will shut off if the motor gets too hot from running a long time. That's a pretty standard safety feature on a lot of electrical products.

You could always put the compressor on a timer so it only gets power for the time of day you use it like 10am-5pm or something.

You could also put it on a switch so you aren't unplugging it every day, just pressing a button.

There is a switch on my air compressor that when I want to use it I just turn it on to auto.

My dad has always had compressors with switches in the garage. We'd find out in the middle of the night if someone was using it and forgot to turn it off. LOL

My grandfather always kept his air compressors on regular wall mounted switches and we used them almost daily on the farm.

https://www.northerntool.com/s.../product_22938_22938

Yeah, switched outlet. On for use, off otherwise.

Yep, thanks to the three of you. I'll probably do that eventually. It didn't bother me till it was about 10 or so years old.

I have a honkin' great 12cfm Quincy with a 5 horse motor on it. Runs on 220. Plugging/unplugging is not an option due to start current.

Fortunately, it has a magnetic starter with 110v coils, so I wired an ordinary light switch on the coil side. I can turn that switch off and not worry about it trying to start when I'm plugging/unplugging it (I use the same outlet for my welders) or running 2-3 times a day to replace air loss due to leakage.

I just flip the switch and wait for it to build up pressure when I need it, and try to remember to flip it off when I'm done. If I forget, the reminder is unmistakable...

They make a small valve you put right after the cut off valve that stops air flow if it exceeds normal usage, shown in the link.
There are other more expensive versions that can also cut the power if the flow gets over a certain amount.

https://www.industrialaircompr...biz/product/OV-SCVS3

It already exists, and is really cheap.

Something like this:

120v:

https://rover.ebay.com/rover/0...2Fitm%2F151350473320


240v:
https://rover.ebay.com/rover/0...2Fitm%2F162423849397

If your able to do some direct wiring, here is one rated for 230 volts ac up to 30 amps. It could handle the big 60 gallon size compressors up to 3hp:

https://rover.ebay.com/rover/0...2Fitm%2F302953159931

I recall in parts of England, that due to their high cost of electricity (nuclear), that homes had a little slider on/off switch on the actual wall outlets so that you could cut the power to the plugged in device. This helped conserve power lost to “vampire” electricity still running to said device and lost as heat.

My grandfather got tired of the family forgetting to shut od the switch to the compressor, and installed a rotary timer switch for it.

Spin the knob for 60 minutes, then it auto shut off. Need more air? Spin it again.

Once I hardwire my compressor, I'll likely do the same.

They make WiFi adapters that go between the plug and the outlet, and WiFi outlets as well. Stupid simple to use with the easy app it requires. I have a few around the house for lights and what not and they always work. Assuming you have WiFi in your shop, would be an easy setup.

The thermal switch on the motor will probably trip after a little while.

This actually happens, I burned up a really nice dewalt 30gal compressor because a hose blew when I was not home. It ran till the compressor locked up, I counted my blessings it did not start a fire.

It did give me the perfect excuse to by a 60gal 5hp IR compressor. I solved the future issue by installing a ball valve right at the tank outlet. Turn it off and on before and after use.


Always have a full tank of air and even helps eliminate bleed-off.


Tommy

I can sympathize with the OP. My little Craftsman compressor is plumbed to one of those retracting reel thingamabobs hung off the garage rafters. Little did I know the hose on that reel was degrading and developing tiny little air-leaking cracks. After about the third time I went to check the door between garage and house when locking up for the night and heard the compressor running I thought "Ok, this isn't normal. What's up?"

When we go on vacation, turning the compressor off is on the checklist.

I like the wind-up timer idea. I think I may do that. Usually the only time I need more than sixty minutes of air is when I'm lubing the big mower's bazillion Zirk fittings.

In fact: I'm certain I'm going to do that. Thanks for the hint, Gibb!

quote:

Originally posted by horsedoc:

I solved the future issue by installing a ball valve right at the tank outlet. Turn it off and on before and after use.

I have a similar valve on the compressor in the hangar. Additionally, since the compressor is used maybe one day a week if that much, we just turn the circuit breaker off when the compressor is not in use.

quote:

Originally posted by V-Tail:

quote:

Originally posted by horsedoc:
I solved the future issue by installing a ball valve right at the tank outlet. Turn it off and on before and after use.

I have a similar valve on the compressor in the hangar. Additionally, since the compressor is used maybe one day a week if that much, we just turn the circuit breaker off when the compressor is not in use.

The problem with that is it relies on remembering to do something in the absence of need, rather than as a result of a need.

As anybody who's ever had to walk around the house turning off light switches can tell you: The latter is a far more reliable incentive than the former

quote:

Originally posted by ensigmatic:

The problem with that is it relies on remembering to do something in the absence of need, rather than as a result of a need.

Really no different from a shutdown procedure in an airplane. You do things in a certain order. Similarly with the compressor, if you're finished using it, close the valve and turn the breaker off.

Lock the door when you leave the house. Lock your car when you get out. Put your gun away when you remove it from your belt. Standard stuff.

Quarter turn brass ball valve on the output of the compressor. It's nice to have air pressure as soon as you open the valve. There will always be leakage in the lines, so putting a valve in will keep your tank pressure up. Then you don't have to wait for the compressor to pump up pressure every time you turn the electric switch on or plug it in.

quote:

Originally posted by horsedoc:

It did give me the perfect excuse to by a 60gal 5hp IR compressor. I solved the future issue by installing a ball valve right at the tank outlet. Turn it off and on before and after use.


Always have a full tank of air and even helps eliminate bleed-off.


Tommy

This ^^^^^. did it many years ago, and works perfectly, plus it is inexpensive!!!! win-win

If you install a rotary timer in series with a normally closed solenoid valve you keep your pressure and shut off the motor to help protect against things like a stuck pressure switch or a broken belt...