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I want a power outlet that automatically shuts off after a period of time. Answered

I want a device to plug my air compressor into that shuts off the power if the compressor runs for more than 20 minutes at a time. I leave my air compressor on and I am afraid that a leak will develop or a hose will burst leaving my compressor to run hours or days before I find it. I want it to sense when the air compressor starts pulling power and starts a timer. If the compressor is still running when the timer reaches either a preset time of around 20 minutes or an adjustable time, the power to the compressor is shut off until it is manually reset. My compressor is 110 volts and I live in the United States.

Maybe such a thing exists but I haven't been able to find it.

Thanks for your help,


I used to empty my tank after each use, but living in a dry climate, very little water accumulates. Now I just shut it off and disconnect the hose. The hose connection is a point where a bit of leaking happenned. Now it can sit for days without leaking down.

I have a compressor with a 33 gal tank connected to a manifold with a quick connect. The manifold supplies pressure to hose reel on the wall with a quick connect at the end that I use when I need to fill a tire outside the garage and other tasks. The manifold also supplies air to a filter/regulator that connects to another hose on a reel with a quick connect on the end that I use for nail guns/staplers in the shop. The manifold also has another drop with a valve to clear moisture or connect something else. If I use my compressor over the weekend, shut it off, it has usually lost all pressure by the following weekend before I get back out there. Maybe if I disconnect the compressor from the manifold when I leave the shop it will maintain pressure but that is also not convenient. So if we are done trying to tell me that I don't need this, can anyone tell me if it exists? Thanks to Downunder35m, I at least know that I am looking for a "relay timer". I found a couple that might fit the bill with a "one shot" mode that seems to do what I want, but it needs to be wired and apparently the instructions are horribly translated from chinese to english. If you search for "Sestos Digital Quartic Timer Relay Switch" on Amazon you will see what I am looking at. I don't mind wiring it if there are precise instructions.

Sorry if we seem to be telling you that you don't need the switch, just pointing out there may be something else wrong with your setup based on our experiences. But I will offer this, maybe just a shutoff valve to your manifold is the fix to keep your tank from losing pressure. Turn that off before you go away. I know, it is the same thing as turning off a power switch, please let us know how things turn out.

what about an outlet timer

They are usually used as lamp timers but it will probably work with a compressor

slow leak would be indistinguishable from air tool use. Is there a reason not to just shut it off manually when you leave the shop? Or wire it to shut off with the lights?

I use the compressed air very sporadically, to blow sawdust off my tools or to shoot brads and pins. It is just really handy to have it available when I need it. I don't want to turn it on and have to fill the tank, pipes and hoses each time I go into my shop. I can't imagine doing something that would require the compressor to run continuously for more than 20 minutes or so, even if I was spraying finish, I would stop often enough that the compressor would stop running.

Does your compressor have an auto shutoff based on pressure? Once the tank fills to the set pressure, it stops. The air is still in there when you leave it and you should at the most have minimal bleed after a few days. It would at the most take only a few minutes to recharge if you turn on the compressor when you want it. Unless you are in the habit of purging the tank after each use, you shouldn't have to wait to use it the next time. After each use I do a complete shutdown and purge because I don't like having a high pressure thing hanging around and supposedly unfiltered air condenses inside for rust.

I only have a cheap compressor from the home depot but unless I have a leaking connection the pressure stays up for several days.
In the good old days before everything needed to be programmed we used timer relays.
Connect one to the pressure switch on the compressor (or parallel to the motor).
Compressor starts, relay timer starts too.
If the power connection for the compressor goes through the realy of the timer AND if the compressor runs for more than what the timer is set for it will cut the power connection.
Only problem here is that you would need a "locking" relay in the timer for this, meaning it does not have a fallback state and need a manual reset as otherwise the motor would just start again once disconnected as the pressure is still indicated low.

Fix all air leaks on the connections and tools and there should be no need for anything else.