Kellogg American b321 -- bogging down

[CapnTank]

Hey everyone! Thanks for letting me join the forum!!

I recently acquired a new to me vintage Kellogg American B321 compressor. I replaced the belt, the wiring to the motor, and put on a new pressure switch. Plugged her in and she started first try! Amazing. I have not gone into the guts of the compressor yet, change the oil, etc. because I wanted to see what I was working with first.

She runs great until around 45 psi -- then it bogs down. At around 50 psi I turned it off as it was sounding rough. So, couple of questions:

1) Does anyone have the old service manual for this girl? I'm sure it needs new oil, etc.
2) Do you think the bogging down is being caused by the belt tension? I am guessing not since it will run great at the beginning.
3) Any thoughts?

Thanks for you help!!
-Mike

 

[MacMcMacmac]

What size motor is on it? What is the motor rpm? What is the pump rpm? What voltage are you running? Single or 3 phase power?

 

[CapnTank]

Hey Mac,

Thanks for the questions, I appreciate your help.

I've attached two photo's, but here are the details:

1.5 hp
1725 RPM
Hooked up to 110 volts

I might move it to 230 power once she is up and running, but the closest outlet is on the other side of my shop, so I'm hoping to make sure it works before I rearrange everything.

 

[MacMcMacmac]

Looks all stock to me, so the motor and pulley ratios should be good. The only thing that is standing out to me is the supply wire seems a bit wimpy for 20A. You think you might have some voltage drop issues? If anything serious mechanically was wrong you would know it from startup.

 

[CapnTank]

Hey Mac,
That's a valid question. It didn't have a plug with it when I got her -- so I went with a 14 AWG plug -- I'll try an 8 AWG and see if that fixes the issue.
Thanks for the input.
-Mike

 

[Jagmandave]

I would go to the 220V setup, then try it again.....if it does the same thing maybe the motor is dirty - but 1.5hp seems light for that size compressor.....

 

[CapnTank]

Mac, you are certainly onto something. I kept it at 110 but used some 10 AWG wire to build a makeshift plug whip. She made it to 60~ psi before starting to bog down.
I'll go to 220 with it next. The only issue is that I don't have a service manual for the motor so I'm going to have to hunt for the proper wiring changes to turn it to 220.

 

[pancho400cid]

There may be a wiring diagram on the inside of the lead box cover.

 

[CapnTank]

I had hoped so too, Pancho. Alas, no dice.

 

[walta]

The manual says
500 RPM for 1.5 HP and 175 PSI
550 RPM for 1.5 HP and 125 PSI
Do the math for your current pulley setup

The next question is how much current is the motor using when it bogs down? Do you have a clamp on amp meter?

http://kellogg-american.com/wp-content/uploads/2015/07/K321-Manual.compressed.pdf


Walta

 

[yatg]

You didn't say, but did you check the air filter?

 

[CapnTank]

Hi Yatg,

Valid question. I took it off and cleaned it before I fired it up the first time. It's an oil filter, and I haven't taken the canister off, again really hoping to find a manual, but I cleaned the filter and I could feel oil in it. Looked 'cleanish'.

 

[Ringo]

Everyone here has great ideas as to what the issue might be. I rebuilt a 1957 Kellogg 321 last year and I can tell you it’s a great compressor. I would venture to say your problem is on the “power” side of the issue and not the pump side. If your not having belt slippage I would say the motor is under powered. 1.5 hp is a bit small for this pump, it is rated for a 3-5 hp. Leland faraday motors are great but they too can get dirty and just need a good cleaning. But my guess will still be that you are under powered with this setup. Btw, what year is this? It should have a build date on the tank tag.

 

[MacMcMacmac]

A 321 is a 1 to 2hp pump. The motor is sized correctly.

http://www.aircompeq.com/ka.htm