Compressor woes?

[sparky567]

This thread is for you people that have a compressor in a workshop which has no heat. In Portland Oregon it does not get that cold over the winter. But we do the odd artic blast that we've got this week.


Under normal temperature the 5hp Husky compressor starts up ok, but the moment the temperature drops below freezing or near to that, it tries,and tries and trips the breaker, hence no start!!! What I was doing, was to remove the belt guard and give a couple winds by hand and sometimes it would start and sometimes it wouldn't. Any ideas regarding my situation. I was thinking of building some kind of doghouse with a 25 watt bulb inside the doghouse to cover the motor/pump assembly.

I've also looked at the thread
(by the way my compressor is identical)
www.hobartwelders.com/weldtalk/showthread.php?t=30171 This would be the next step.

[sparky567]

I forgot to put in any ideas for me please?

Sparky

[bandsawguy]

my 5hp Ingersoll Rand starts fine in the cold. Is the unloader valve releasing the pressure in the cylinders after it shuts off. I am think some moisture got in it and its frozen and holding pressure in the cylinders. This would cause the motor to overload as its trying to start with a full load on.

[Hotfoot]

That could be it (beautiful picture, by the way!)...Why not work it over with a heat gun for a bit? Once it gets running, it'lll produce its own heat.

[sparky567]

That could be it (beautiful picture, by the way!)...Why not work it over with a heat gun for a bit? Once it gets running, it'lll produce its own heat.

Yeah! That picture is a work of art ! In other word I would have to pull out the heat gun, every time. In the winter time, I don't go in the shop (garage) that often, maybe two or three times a week. You did not comment on the doghouse idea!

[bandsawguy]

I think once you get the moisture out you should be ok. I can't see why it would keep freezing up on you.

[ptsideshow]

Humidity the bane of out door compressors, as been stated the unloader valve, also could be some moisture on the reed valves as a lot of the new compressor valves are like the flat spring reed valves. And can freeze under high humidity and low temps. As once its shut off the moisture can condense rapidly, causing freezing.

We had problems in the schools in parts of the building with cheap compressors used as boosters for the heating control systems. Heat was only on when the building was occupied. During cold snaps and weekends there would be problems.

The cheapest and easiest would be to try a light bulb and foam cooler to see if it makes a difference. Then you could head out to the shop and turn it on an hour before you want to start working. or just do clean up till it warms the pump up.

[Sberry]

get a cranck case heater like they use in refrig units, they can be found at Grainger or better yet heating and cooling/referig jobber. Lighter weight oil too, one of the multi visc, 5w30 synths.

[sparky567]

You said
"Is the unloader valve releasing the pressure in the cylinders after it shuts off"
Sorry, bit I would not know what a unloader valve looks like it bit me in the nose. It's not the pressure relif valve is it? The only valve I can think of is the brass that has a sort of key ring on the end.MaYbe you can help me find it...It does blow air after it's running cycle . Is that the valve that you're talking about?



thanks

[Roger]

Only compressors with unloading valves I have seen at Home Depot is engine drive twin tank oil lub compressors like this one http://www.homedepot.com/webapp/wcs/...3+90401+524403 or Husky brand equivalent. When compressor reaches max pressure pilot valve puts air receiver tank pressure to unloaders on compressor cylinder head holding intake valves open and sets engine throttle to idle. Compressor stops pumping air reducing load on engine so it can idle. Check valve in air tank inlet isolates tank pressure from compressor. When Tank pressure lowers to low set point (minimum working pressure) pilot valve bleeds pressure to unloaders letting compressor inlet valves operate normally so compressor starts pumping air.

Better compressors have bleed valve between compressor and air receiver that is closed by compressor oil pressure so compressor starts with less load. This system will open bleed valve if oil pump fails reducing compressor damage.

Your compressor is probably splash lubricated.
If your compressor has check valve on air receiver inlet then electric normally open solenoid valve teed in between receiver and compressor would bleed pressure until compressor starts making starts easier. This valve would auto operate by same switch that starts/stops your compressor to maintain operating pressure. With a good check valve that doesn't leak air back to compressor you wouldn't need this bleed valve because compressor head valves always leak a little But cheap check valves aren't much better.

I have used electric powered compressors that had unloaders and you could set it to run continuously and auto load and unload to maintain pressure under high air usage or stop/start motor to maintain pressure.

[enlpck]

Many smaller compressors don't use a seperate unloader... it is part of the pressure switch. When the switch opens (turning off the motor) the mechanism opens a small valve by pressing what that looks like a schreader valve stem. Sometimes a seperate tube is run to the switch for this, other times (mostly the smallest compressors only) the outlet of the pump runs next to or under the switch with a tee that may no be real visible. The check valve is often tight on the inlet to the tank, and smaller ones can look like they are just a fitting until you look closely. The idea here is that the pump and motor will come up to speed faster than the short line from the pump to the check valve will pressurize enough to stall the motor.

The best compressors just unload (hold the intake valves open) and don't worry about check valves or draining the line from the pump to the tank... the outlet valves on the cylinders are sufficient. Once the pump is up to speed, the inlets are permitted to close normally and the pump makes pressure.

[Amos F.]

I think you have all good ideas. Only thought I have on the subject is, may be one start capacitor is gone?? Had a rash of these on the farm last few months. Some motors we have will start with a blown capacitor or two even, but when it gets cold the lack of start capacity shows up.

[greywynd]

I've got the same compressor, and have noticed in the colder temps it doesn't like to start. But then, neither does my old diesel truck.....

I usually just try to avoid doing anything when it's that cold, and wait til warmer weather. I do try to keep my portable air tank full through the winter though, that way I have some compressed air available if the need arises.

[wmgeorge]

This thread is for you people that have a compressor in a workshop which has no heat. In Portland Oregon it does not get that cold over the winter. But we do the odd artic blast that we've got this week.
Under normal temperature the 5hp Husky compressor starts up ok, but the moment the temperature drops below freezing or near to that, it tries,and tries and trips the breaker, hence no start!!! What I was doing, was to remove the belt guard and give a couple winds by hand and sometimes it would start and sometimes it wouldn't. Any ideas regarding my situation. I was thinking of building some kind of doghouse with a 25 watt bulb inside the doghouse to cover the motor/pump assembly.


I've also looked at the thread
(by the way my compressor is identical)
www.hobartwelders.com/weldtalk/showthread.php?t=30171 This would be the next step.

That is what I would do, build a insulated dog house around the compressor with a couple doors you could open (or take off) to let fresh air in when it warms up a bit. When you put in the light bulb make sure it can't touch something inside and start a fire.

I'd use that aluminum foil covered Fiberglas insulation they use for wrapping furnace duct.

[vicegrip]

All good stuff.........

Unloader, capacitor...etc.
A simple clamp-light with an infrared heat-lamp bulb in it.....
can be a foot away. Turn it on, have a cup of coffee or a brew...
and off ya go.

In the 70's we would position a heat-lamp about 6" from the crank-case,
of my Dad's snow-blower.....out in the shed. Just turn the braker on in the house,
anticipating going out-side in say 20 minutes, and she'd fire up with one pull.

Cheers