Air Compressor Bogs on startup..

[tmunsch]

Campbell Hausfeld 60 gallon vertical compressor. Just started running really slow on start up, then eventually picks up speed...

Did a search and found a thread about check valve.....so here's what I have done so far...

3 different check valves...still bogs at startup
New motor...same
New pressure switch...same
Relief valve working....releases air on shutdown...

This one has me baffled......if you bleed the tank off completely, it starts and runs just fine. I let it get to 40PSI, then 60PSI, cut it off, restarted it and it does the same thing.

I disconnect the discharge air line, starts and runs just fine.....this problem only occurs when there is 40 or more PSI in the tank...

In addition, there is no appreciable voltage drop on startup, or during running, 30 amp circuit, 10 gauge wire....amperage is not out of spec....

At my wits end here guys....help...

T,

 

[rpcraft]

Might be an issue inside the piston like scratched or scored cylinder walls? have you tried rotating it without anything attached to build pressure and see how free everything moves that way?

 

[tmunsch]

Might be an issue inside the piston like scratched or scored cylinder walls? have you tried rotating it without anything attached to build pressure and see how free everything moves that way?

Yes, rotates smoothly. Can feel resistance and also hear air escape when turning. I pulled the copper pipe off the discharge side when I did this, thinking the same thing as you....doesn't bind or make any weird noises. Runs just as quiet as always has with everything connect and motor running........

T,

 

[Kaizen]

Belt? Same belt through all of the changes?


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[MacMcMacmac]

I'd check the discharge line to see if there might be a piece of loose **** or coked oil stuck in there that is acting as a restriction.

 

[tmunsch]

Belt? Same belt through all of the changes?


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Same belt, no grooves or wear evident, no squealing or odd noises. Like I stated, runs right up to speed unloaded.

I'd check the discharge line to see if there might be a piece of loose **** or coked oil stuck in there that is acting as a restriction.

Ran a brush through it and cleaned it out....

I forgot to mention. I pulled the un-loader tube off once it shut off and no air was leaking by....

T,

 

[marinusdees]

Sounds like the unloader doesn't work.

 

[Olafur]

Does it reach full pressure - how much?

Does it start at all @80 psi or higher pressure?

For how long does it run "slow" before it picks up speed?

Normally the unloader is out of the picture after very few turns of the compressor since by then it has already filled up the "unloaded" volume and is pumping against the tank pressure. So - compressor running @1000 rpm, that's 17 rounds per second. I hope you get my drift - it takes split second for the compressor to do this. If you are hearing it struggling for several seconds the problem isn't the unloader -unless it's barely moving.

 

[Jason280]

Make sure the belt has the correct tension. My IR 80gal was doing the same thing, found out the belt wasn't tight enough. As a result, it was slipping enough at start up to sound like it was bogging down.

 

[bdelmar2]

Sounds like the unloader doesn't work.

That's what it sounds like to me also.

Not a compressor expert, but exactly what our old compressor did when the unloader melted.

 

[66cj225]

Didn't see comparison of amp draw to name plate. Voltage drop on startup?

 

[66cj225]

There's got to be some voltage drop on startup unless you live next door to the High Line transformer. I'll bet across the pressure switch or the contactor if you have one.

 

[EOC_Jason]

Assuming your unloader works (you should hear a hisssss after shutdown each cycle)... You said you've replaced the check valve and checked that...

First thing that comes to mind is belt tension... I've had compressors do similar acting like they were bogging down and I don't know why but tightening the belt tension resolved the issue.

Another thing that comes to mind is the oil... We are starting to get cold weather... Granted you live in Baytown so it's still probably not that cold there... But a good synthetic compressor oil will ensure a smooth running pump and not have to worry when it gets cold.

Maybe also double-check all your electrical connections to make sure they are good and tight, from the breaker, to the plug / connector, pressure switch, etc...

 

[tmunsch]

So it appears that it was belt tension after all. I went back and put the gorilla grip tighten job on it and it now comes up to speed immediately......I though I had the belt plenty tight, but that doesn't seem to be the case. You would think something so obvious would be hard to overlook.....thanks for all the help guys, this place is great. It is always good to have another set of eyes on things......

Have a Happy and Blessed Thanksgiving.....

T,