need some help with a speedaire

slopecarver · Mar 26, 2010

So I've aquired this compressor from my gramps, it is a 2hp 30gal Speedaire. I've been having some problems getting it working properly. It would pump up the tank to about 40psi then either stall out or spin the drive pulley on the belt, this was in 110v mode on a 20amp circuit. It would also have problems starting up when there is air in the tank. Would it be better to retrofit a v-belt drive? Is there something wrong with the motor, it seems like it just doesn't have the power. Who in their right mind would have a 24 amp 110v circuit? I have an old Master brand motor 3/4hp at 1725 rpm, if I were to set it up with the correct speed reduction would it work?

Zrexxer · Mar 26, 2010

Sounds like your check valve is not operating properly.

slopecarver · Mar 26, 2010

Zrexxer said:
Sounds like your check valve is not operating properly.

check valve works fine, motor just seems underpowered and the belt has problems with traction on the drive pulley (belt needs a bunch of tension not to slip). anyone else want to give it a shot?

lilredex · Mar 26, 2010

I would look at the unloader valve first, sounds like it is somehow blocking the compressor output and causing it to stall and overloading the belt drive. Try it out of the circuit, if you can, and operate it manually. That way you can confirm that the compressor head and motor are OK.

I have essentially the same head driven by a 2HP 3450 RPM motor also, and it will operate much better on 220V if you can change.

http://www.about-air-compressors.com/unloadervalve.html

Identaltech · Mar 26, 2010

If you unloader valve is working right you should have no problem with start up when air is in the tank because there is no air pressure at the head.
have you checked the run capacitor?
whats going on with the terminal #3 (wire looks burnt)
Belt looks very worn(missing chunks)

slopecarver · Mar 27, 2010

so it was the unloader valve, I could manually depress it to release the air and the compressor would start just fine under pressure. Lubed it up with some wd40 and tried reinstalling it, snapped the threads off with minimal effort. where can I get another one of these? The pressure switch is a Furnas 5gb69

lilredex · Mar 27, 2010

Need a place that sells compressors, etc, yellow pages maybe.... If you were here, you could just run over to Princess Auto and maybe get another. Will it come apart so you could silver solder that broken piece back on to repair? Looks like more than just a ****** as I see a valve seat machined also in there. You might be lucky enough to fix it if you clean it up well and attempt a silver solder job.

You should seriously think about switching it to 220V, it will be much happier. When I switched mine, I found that a replacement cord for my Lincoln AC225 welder was about a third of the cost of buying the wire and a 50 Amp plug, so that is the way I went. Guy at the welding shop got a kick out of that one.

slopecarver · Mar 27, 2010

lilredex said:
Need a place that sells compressors, etc, yellow pages maybe.... If you were here, you could just run over to Princess Auto and maybe get another. Will it come apart so you could silver solder that broken piece back on to repair? Looks like more than just a ****** as I see a valve seat machined also in there. You might be lucky enough to fix it if you clean it up well and attempt a silver solder job.

You should seriously think about switching it to 220V, it will be much happier. When I switched mine, I found that a replacement cord for my Lincoln AC225 welder was about a third of the cost of buying the wire and a 50 Amp plug, so that is the way I went. Guy at the welding shop got a kick out of that one.

There is no fixing the existing valve. I'm not in canada so I do not have a princess auto, I do however have a horror fright nearby so I'll pay them a visit today. I have a feeling the compressor isn't actually 2hp, it does not trip a 15 amp breaker at 110v.

Kev442 · Mar 27, 2010

My '74 Craftsman is basically the same unit. If you were able to manually depress the unloader and it worked, it means the pressure switch was not doing its job either. You can buy a new pressure switch like this one on ebay like I did:http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190373895584 It includes a 1/4 unloader.
I wanted to lower the pressure from 155 to 125 PSI as I thought that would be easier on the pump head/motor in it's old age. I also replaced the check valve and regulator while I was at it. The $65 I invested was well worth it to me.

But! If your unit starts at zero, it should pump all the way up and shut off. If it stalls even starting at zero pressure, you have other problems with the pump or motor. I would start by switching to 220 myself.

jarhead · Apr 19, 2010

If I am reading this post correctly the unloader valve was the problem.

I have this exact compressor and it tore a belt in half a week ago so I bought another belt. After installing the belt I ran the compressor for a while with no problems.

I shut it off and turned it back on and the belt started to squeal. The electric motor was spinning but the air pump was not. I turned off the power and tried to turn the air pump and it wouldnt move.

So my question is where do I find the unloader valve?

Thanks, Joe

Kev442 · Apr 19, 2010

Physically? Follow the small 1/4" copper tube down to where it meets the box. The unloader will be on the end of it. When the compressor shuts off, the metal tab is supposed to depress the spring loaded valve. If it is not getting depressed, then you need a new pressure switch, not an unloader.

jarhead · Apr 19, 2010

Kev442 said:
Physically? Follow the small 1/4" copper tube down to where it meets the box. The unloader will be on the end of it. When the compressor shuts off, the metal tab is supposed to depress the spring loaded valve. If it is not getting depressed, then you need a new pressure switch, not an unloader.

Thanks I will check it out tomorrow.

Thedroid · Apr 20, 2010

Nameplate says 2hp. I don't think that 3/4 would have a chance. Doesn't trip because the belts slipping. Clean it up, and also clean up those connections. Fix your valve, and everything should be fine.

Major Ramifications · Apr 20, 2010

Yes, I was going to say you definitely have an unloader issue. Any time it won't start under load, that is the first place to look.

Keep the motor that is on it. It is much stronger and newer than the old relic. Keep the multi-v belt setup for sure, but replace the belt.

Since this is a Grainger compressor, parts should be available from Grainger. You could also try CHpower.com, since this unit was made by Campbell Hausfeld.

The shotgun approach to problem solving is seldom successful and always expensive. Use your head, figure out where the problem lies and take appropriate action. Fix your unloader issue, whether it is the valve itself or it's activation, change that worn-out belt, and for God's sake find or fabricate a belt guard.

jarhead · Apr 20, 2010

jarhead said:
Thanks I will check it out tomorrow.

It was the unloader valve, tip was bent. Bent it back and re-installed it, working good again.

It amazes me the stuff you learn on these forums!

Thanks, Joe

Charles (in GA) · Apr 20, 2010

That compressor is identical looking to a smaller (1 hp 12 gal) Craftsman I have. Same green, same fitting out the end of the tank, same "finned" or ribbed iron manifold at the gauge/pressure switch/check valve, same brand of pressure switch/unloader, same type of belt (unusual for the vintage), identical looking pump.

Charles

need some help with a speedaire

slopecarver

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Zrexxer

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slopecarver

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lilredex

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Identaltech

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slopecarver

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