Puma 12V Compressor

[Otter]

Whats the pro/con of keeping the pressure switch connected? I’ve moved my Puma to a case and have room for the switch but is it really needed? And if I do keep it, do I really need the unload valve on it if I keep the pop off connected?

Obv I’m not an expert on this system.

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If you remove the pressure switch and unloader valve, you need to make sure you have special fittings so nothing builds pressure. Otherwise it will blow up. You need constant flow fittings and you need to make sure no one ever plugs in a regular air line into your compressor.

 

[ntsqd]

There is a pressure switch, an over pressure blow-off valve, and an unloader valve. The pressure switch turns the compressor on when the tank or line pressure drops too low and off when the pressure reaches the set point. If you are not running an air tank in the system you aren't going to get it's full benefit, but it does make a handy on/off switch. These compressor motors pull a large amount of current, not just any normal switch can handle that load.

The safety blow-off valve is there in case the pressure switch sticks on and pumps the line or tank pressure above the max operating pressure for any of the parts in the system. If all you ever use the system to do is inflate tires then the safety blow-off valve won't have much to do. However, if you have an air tank or are regulating the line pressure (say to operate ARB's) then you absolutely want to retain the safety blow-off valve.

The purpose of the unloader valve is so that the line between the compressor and the tank is not under pressure when the compressor starts. If it is under pressure that makes it much harder for the compressor to start. It "unloads" the compressor for starting. If you have no air tank in the system that makes it bordering on unnecessary. Only if your use tends to leave the air line under pressure all of the time would you want to keep the unloader valve. Note that the fitting on the Puma air tank with the large and the small copper tubes going to it also contains a check valve to keep tank pressure from bleeding back out into the tube from the compressor. Without that check valve the unloader valve would simply drain the air tank.

 

[kwon-offroad]

The purpose of the unloader valve is so that the line between the compressor and the tank is not under pressure when the compressor starts. If it is under pressure that makes it much harder for the compressor to start. It "unloads" the compressor for starting. If you have no air tank in the system that makes it bordering on unnecessary. Only if your use tends to leave the air line under pressure all of the time would you want to keep the unloader valve. Note that the fitting on the Puma air tank with the large and the small copper tubes going to it also contains a check valve to keep tank pressure from bleeding back out into the tube from the compressor. Without that check valve the unloader valve would simply drain the air tank.

This is very helpful. Thank you. I simply went 1/2"NPT to 1/4"NPT from the check valve directly to the 3 way pressure switch and retained the unloader and pop-off. The intent of my question was to remove anything that was not absolutely necessary as it will only be used to fill tires and high pressure inflatables.

 

[kolimem]

This is very helpful. Thank you. I simply went 1/2"NPT to 1/4"NPT from the check valve directly to the 3 way pressure switch and retained the unloader and pop-off. The intent of my question was to remove anything that was not absolutely necessary as it will only be used to fill tires and high pressure inflatables.

Thank you both. It was one of the problems I was looking for a solution to today. By checking the origins, I finally reached the source of the problem. It's much better now. I am grateful for this information.

 

[DSRTRDR]

Has anyone had a PUMA failure?

My 1st PUMA was purchased in 2007 and has been run monthly since then without issue

Best Chinese product even purchased by me

I wouldn't call it an outright failure, but the Puma purchased in 2012 for our 80 has as of recently been taking excessively long to air up - and by excessive, I mean needing to run it for upwards of 15 minutes on a 4-tire-hose-around-system (no hose leaks or chuck leaks detectable; 315 tires, going from 18-ish to 35-ish on the psi's) - we'll pull it tomorrow for further diagnosis . . .

the Puma in the LX450 that we got a year later is still going strong - having seen about the same amount of run-time as the one in the 80

the Puma in the Blazer that we got just after Kevin started this whole thread is also still in fine shape . . .

 

[80t0ylc]

I wouldn't call it an outright failure, but the Puma purchased in 2012 for our 80 has as of recently been taking excessively long to air up - and by excessive, I mean needing to run it for upwards of 15 minutes on a 4-tire-hose-around-system (no hose leaks or chuck leaks detectable; 315 tires, going from 18-ish to 35-ish on the psi's) - we'll pull it tomorrow for further diagnosis . . .

the Puma in the LX450 that we got a year later is still going strong - having seen about the same amount of run-time as the one in the 80

the Puma in the Blazer that we got just after Kevin started this whole thread is also still in fine shape . . .

I would check your electrical connections. Found a badly crimped pin in my Anderson connector that was affecting mine. I have since got a hydraulic crimper for use on the larger gauge wires that I"ve installed in my aux batt system. Performance with this compressor is significantly affected by the electrical source, both voltage and current.

 

[ntsqd]

I had been seeing an occasional trip of the 50A breaker that I had the compressor system on. I had calculated that the running motor would draw about 47 amps. It seems that the motor start-up in-rush current could exceed the breaker's tolerance for short term over-current conditions and would pop it. A 60A breaker has been substituted and it appears to be working well. As I've mentioned, my only horn is a small air horn that dates back to the mid 80's (sourced from JC Whitney!), so my Puma runs at least every morning when I start the truck to go to work.

 

[DSRTRDR]

I would check your electrical connections. Found a badly crimped pin in my Anderson connector that was affecting mine. I have since got a hydraulic crimper for use on the larger gauge wires that I"ve intalled in my aux batt system. Performance with this compressor is significantly affected by the electrical source, both voltage and current.

we have also experienced a bad crimp in an Anderson connector a few years ago

today's systematic testing of the Puma and air-up equipment revealed that the hose barb that snaps into the Puma air chuck was leaking - hose with said barb came as a Husky product from Home Despot

 

[80t0ylc]

Bad crimps and bad hose fittings.....can't blame Puma for that! Still the best investment & performing mobile air compressor that I've owned. Thank you Kevin, for finding this and sharing the results back in July of 2007! A lot of folks have benefitted.

 

[MATTHAIAS]

@LandCruiserPhil I can’t tell in the picture how you attached the compressor to the harbor freight case. Did you bolt it?

 

[LandCruiserPhil]

Yes and the original box and the needed bracket is available PM me

 

[Douglas S]

I finally got my hands on one of these, not a simple task in Canada. I ordered one probably 10 years ago from Amazon Canada and was sent a 24V version, returned it but it was the only one they had and 12V never came into stock.

To get this one I had it shipped to my friend in Detroit who then shipped it to me.

 

[Jim S.]

Nice, you're going to like it.

 

[Heckraiser]

Can someone spell out for a dummy exactly what would be necessary to safely run a fitting straight out of the compressor without using a pressure switch, check valve and all the other associated hardware? I'm hard-mounting the compressor in my 200 and I'd like to 1) keep it simple and 2) keep it as compact as possible. Hoping to run similar to @LandCruiserPhil or @Blue77FJ40. I've heard cryptic references to blowing stuff up if it's not done right, which of course I don't want to do, but these setups look super simple and you guys apparently haven't burnt down your rigs yet

 

[Blue77FJ40]

Can someone spell out for a dummy exactly what would be necessary to safely run a fitting straight out of the compressor without using a pressure switch, check valve and all the other associated hardware? I'm hard-mounting the compressor in my 200 and I'd like to 1) keep it simple and 2) keep it as compact as possible. Hoping to run similar to @LandCruiserPhil or @Blue77FJ40. I've heard cryptic references to blowing stuff up if it's not done right, which of course I don't want to do, but these setups look super simple and you guys apparently haven't burnt down your rigs yet

I added a release valve to the output just before the connection to the coupler. Will post pic soon. You are only running the setup to air up tires. so not much time for catastrophic failure. You can replace that copper line using british thread adapter. Just search my posts for thread specs. I show that in later posts.

 

[Heckraiser]

I think I saw your picture earlier in the thread with a release valve on a tee. That's all that's needed to keep things safe for tire duty? I'll probably be running a 4-in1 tire inflator so run time around 8 minutes.

 

[ntsqd]

Could just put an over-pressure blow-off valve on the output. Set one at 90-100 psi, and then whenever the system gets dead-headed it just blows down thru that valve. They're pretty small normally, could hang down off the outlet fitting next to the compressor head and you'd rarely if ever notice it. Something like this one: McMaster-Carr - https://www.mcmaster.com/50265K23/

 

[Blue77FJ40]

Could just put an over-pressure blow-off valve on the output. Set one at 90-100 psi, and then whenever the system gets dead-headed it just blows down thru that valve. They're pretty small normally, could hang down off the outlet fitting next to the compressor head and you'd rarely if ever notice it. Something like this one: McMaster-Carr - https://www.mcmaster.com/50265K23/

Perhaps I worded it wrong as release valve, but the pressure blow off is essentially the same thing. That's what I installed.

 

[Heckraiser]

Thanks @Blue77FJ40. I now have it all plumbed up and mounted in the 200.

Next question is wiring. I think I'd like to run permanent wires from the battery (on the driver's side) across the radiator support to an Anderson connector and then just plug the compressor in at the Anderson connector to turn it on. What gauge wire should I use for a ~4-foot run? And is there an anderson connector that will work with that gauge and the little wires coming off the compressor?

 

[ntsqd]

They're supposedly a 3/4 HP motor, so 746W (1HP)*.75(HP)/12.0 (worst case VDC) = 46.6 Amps. Call it 50A.

Using: Three percent voltage drop - https://www.ancorproducts.com/en/Resources/Three-percent-voltage-drop and 4 ft. = 8 ft. circuit length (ground path length is part of the circuit) and 50A the chart says 6 Ga. I used the 3% Chart instead of the 10% chart because of it being a motor that you're going to want peak performance out of.

I started out with I think it was a 50A breaker and it would occasionally pop due to the motor start-up in-rush current. I'm now using a 60A 285 series breaker. They're available w/o the Blue Sea Systems label for less. I'd just use the manual disconnect feature on the breaker instead of plugging and unplugging the compressor.

But if you insist on using an Anderson connector I'd use these: Anderson Power Products SB50 SB Series 50 Amp Connector Kit - https://powerwerx.com/anderson-sb-connectors-sb50-50amp