I bought the 12volt puma air compressor from e-bay. It comes with the pressure and on/off switches already. I have temporarily installed it with wires running straight to the battery but want to add some protection. It has a max current draw of 30 amps. Would it be best to install a circuit breaker to it? And would it need to be 30 amps or greater? One of the off-road mags gave me the idea of mounting it in my toolbox and they installed a 100 amp breaker, but i dont think that compressor draws that much. Also, if I am using the switch on the compressor for onoff, do I need a relay? Thanks for any help.
wiring on board air compressor
1 - 13 of 13 Posts
Joined
·
383 Posts
I'm assuming you just want a manual on/off switch, not wired into the ignition.
Use a relay for any circuit. Most switches won't handle any amount of current, no matter what they say. Your fuse should be about 1.5 to 2 times the max current rating. That will protect the circuit and not blow fuses all the time.
Use a relay for any circuit. Most switches won't handle any amount of current, no matter what they say. Your fuse should be about 1.5 to 2 times the max current rating. That will protect the circuit and not blow fuses all the time.
Joined
·
1,091 Posts
Is the on/off switch and pressure switch all prewired and part of the compressor? If so you don't need a relay, just run the power wires to the battery and you're done. For protection put in an inline 40A fuse and wire it with #10 and you'll be fine. If the on/off etc isn't part of the compressor let me know and I'll walk you through it. .....Steve
SteveO said:
yeah, the pressure switch and on/off switch all came pre-wired with the compressor. I orig used 10gague wire to hook it up, but it is smaller than the lead wires coming off the motor, so I got some 6 gague wire from a friend to re-wire it. Normally I wouldnt worry, but it is a good 16 foot run from the battery to the tool box. But before i do that, I wanted to make sure i do it all correctly. I havent seen an inline fuse holder with that gague wire, does it matter if one small section has a smaller wire? The fuse holder would be cheaper, but does a circuit breaker have any advantages? (I can easily carry spare fuses) Thanks for any help.
Joined
·
1,091 Posts
You can use a section of #10 with an inline fuse holder if you need to, it won't make any difference at the compressor because the resistance in that short of wire is nothing. The other thing you might want to do is put in some type of switch system so it's not always cutting in and out when you don't need it. Without a master switch the compressor will start and stop depending on the pressure in the tank. A leak in the system could cause the compressor to run when you're not around and either overheat or kill your battery. Also, if you want it to work only when the truck is running or the key is in you'll need a relay and connect to a switched power source for the control circuit. Decide how you want to control it and when you want it to run and let me know. .....Steve
ps. The breaker's only advantage is it is resettable and available in bigger ratings but for a 30A load I'd go fuse all the way, plus it should never blow anyways so it won't be an issue.
ps. The breaker's only advantage is it is resettable and available in bigger ratings but for a 30A load I'd go fuse all the way, plus it should never blow anyways so it won't be an issue.
SteveO said:
I am only going to be using it to fill tires and stuff like that. I have a TRD and am not plainning for an ARB up front for now. So, the switch that is comes with ought to work for me. I will just use an inline fise holder like you said. Thank you for all of your advice!
Joined
·
216 Posts
Which Puma is that? I'd like to get onboard air. Got a link to the auction, just so I can see what it is you got?
obscurotron said:
http://cgi.ebay.com/ebaymotors/ws/e...tem=4528004256&category=43986&sspagename=WDVW
The link is above, if it doesnt work, just do a search for "puma air compressor", it is the only 12volt one they sell. It does work well, even if it only hav a 1.5 gal tank. In my installation in my toolbox, I can easily also add an additional tank. They go on e-bay for cheap (2-3 gal ones). The manifold that has the regulator and pressure switch has one port that is plugged. All you need to do is take the plug out and run a line to another tank. Or do this and run the outlet off of the extra tank. Either way could work. Also, you can unbolt the compressor from the tank if you want to mout it in a smaller area. I tried to attatch a pic of my installation, but I cant do much with the tiny file size we are allowed.
Attachments
Joined
·
2 Posts
I see this post is quite dated and tried to reach SteveO with a direct message, but apparently I'm too new to be able to use that function...
I've been scouring the internet looking for specifics on wiring an air compressor to my truck and came across this discussion which was very helpful. I purchased a Smittybilt 2781 which has a 45 amp max draw. I would like it to cycle on and off based on pressure (between 90 and 120 psi), only when the ignition is on, with the ability to switch the circuit on and off. I drew up a schematic based on what I've researched so far, which I think isn't quite right. Wondering what looks right, what doesn't, and what recommendations are? I'm not sure how to wire the switch, nor how to access the ignition based power.
![Handwriting Font Drawing Pattern Slope]()
I've been scouring the internet looking for specifics on wiring an air compressor to my truck and came across this discussion which was very helpful. I purchased a Smittybilt 2781 which has a 45 amp max draw. I would like it to cycle on and off based on pressure (between 90 and 120 psi), only when the ignition is on, with the ability to switch the circuit on and off. I drew up a schematic based on what I've researched so far, which I think isn't quite right. Wondering what looks right, what doesn't, and what recommendations are? I'm not sure how to wire the switch, nor how to access the ignition based power.
So you want the compressor to run from ignition on normally but optionally to turn on when the vehicle is off? You dont want the negative black wire on the switch. Use a SPDT switch. One power source from ignition on (tap one of the ignition circuits from the fuse panel) and one constant (radio memory power) and then run the switched power to the pressure switch as already drawn. Example switch attached which gives you an OFF option as well.
![Rectangle Font Circuit component Technology Electronics accessory]()
Joined
·
2 Posts
Ok, so the on/off switch is only connecting positive to positive then, correct (makes sense)? I was thinking I would only want it to work when the ignition is on, and then only when the switch is in the "on" position. So in that case, I could just use one side of the SPDT switch if I'm understanding correctly. Would you just tap into an existing fuse on the fuse box using a fuse tap (one that is controlled by ignition switch)?
1 - 13 of 13 Posts
Join the discussion
