Upgrade Compressor Pump

[tigercreek]

I have an older CH 5hp single stage compressor with a new motor.
I am thinking about upgrading the pump to an Eaton 5hp 2 stage.
Seems like this will be the best bang for my buck rather than getting a new compressor.
Any downside to doing this that I am not aware of?

 

[Packard V8]

Are you wanting higher pressure or greater volume?

jack vines

 

[The Tool Tyrant]

You need to verify Eaton pump RPM range first. Is your motor 3450 +/- RPM or 1725 +/-?
Is your motor 5 TRUE HP? If not, it MAY have issues.

 

[tigercreek]

Looking for greater volume.
Waiting to hear back from Eaton on the RPM.
My motor is a Baldor 5 hp (true) 1725 rpm.

 

[shoot summ]

I did a similar upgrade, my thread is here:

https://www.garagejournal.com/forum/showthread.php?t=278440

The only issue I had was I was trying to spin the pump too fast and my motor was overheating so I dropped the size of the motor pulley. That thread is here:

https://www.garagejournal.com/forum/showthread.php?t=304440

 

[larry_g]

If you want to replace the compressor head then the most important spec is that you need to match it to the motor. "running horsepower" of 3.7 means little to nothing. You need to know the true FLA of the motor to be able to match a pump head to it.

Study the pump heads avaiable here, http://www.aircompeq.com/ka.htm , pay close attention to the pressure and pump speed columns for each pump head. The faster you spin the pump the lower the rated pressure for same HP. These things have to be matched, motor/pumphead and speed/pressure. The horsepower of the motor is going to determine what pumphead you select for the best match.

I only use this Kellogg page as it shows the relationships the best.

lg
no neat sig line

Above is my post in another thread with same subject; https://www.garagejournal.com/forum/showthread.php?t=456839&highlight=kellogg

I also have a post in Shoot's thread linked above.

lg
no neat sig line

 

[tigercreek]

Thanks.
Still waiting to hear back from Eaton.
When I got this particular compressor a couple of years ago the motor had the wrong pulley and was overdriving the compressor. When I replaced the motor I also backed the pulley size down and no more overheating.
I was wrong on my motor speed - it's actually 3450 rpm.
The FLA on my particular motor is 21.38.

 

[The Tool Tyrant]

I checked Eaton's 2 stage 'Inline' compressor specs on their website and they use a 5 HP 1750 rpm motor and turn the pump at 650 RPM. You possibly may encounter issues with changing to such a small drive sheave on your 3450 RPM motor that the belt slips.

On the pump specs page it shows 795 RPM. I'm guessing they want to show maximum output from that particular pump...but yet on their 'packaged' unit, they run it at 650 RPM...so with your 3450 RPM motor you would need a 3-1/8" drive sheave. That's not good!

 

[shoot summ]

I checked Eaton's 2 stage 'Inline' compressor specs on their website and they use a 5 HP 1750 rpm motor and turn the pump at 650 RPM. You possibly may encounter issues with changing to such a small drive sheave on your 3450 RPM motor that the belt slips.

On the pump specs page it shows 795 RPM. I'm guessing they want to show maximum output from that particular pump...but yet on their 'packaged' unit, they run it at 650 RPM...so with your 3450 RPM motor you would need a 3-1/8" drive sheave. That's not good!

I've been running mine like(3" pulley, 630RPM) that for almost 5 years with no issues and no belt slippage. The compressor keeps up very well with a DA Sander, or my blast cabinet.

 

[The Tool Tyrant]

I've been running mine like(3" pulley, 630RPM) that for almost 5 years with no issues and no belt slippage. The compressor keeps up very well with a DA Sander, or my blast cabinet.

Same Eaton pump?

 

[MacMcMacmac]

Watch your belt tension on a skinny shaft motor.

 

[sberry]

Change pressure switch and relief valve. Personally would sell it and buy a factory made unit.

 

[marinusdees]

Change pressure switch and relief valve. Personally would sell it and buy a factory made unit.

Amen.

I would watch Craig's list, offer up, etc. If you aren't in too much of a hurry, you can score. I am personally not a fan of 3450 rpm motors on compressors. The slower you can spin a compressor and get the volume you want the quieter, the cooler, and the longer it will last. And, 21 amperes is marginally a 5 hp motor.