3 phase air compressor was run backwards for 2 months

[jdtreeline]

Hey guys,

I'm a long-time reader and I used to be active here years ago but I have lost my login information, so this Is my first post under the new account.

I have a 3-phase Napa air compressor (baldor motor and Atlas Copco pump) at my shop that I bought and installed brand new a little over a year ago. It has been an awesome unit until recently. A few months ago a garbage truck contacted the primary powerlines that feed our shop and they had to be replaced. When the city restored power to our building they had the phases reversed. I did not notice this until 2 months later when my compressor started pushing excessive amounts of oily moisture out of the lines. Upon inspection, I realized the motor was rotating backward. After many phone calls and emails, I finally got the city to admit their mistake and correct the phasing on the primary side, But they have refused to replace my damaged compressor (yes I have my commissioner and lawyer looking into further action) That's the Backstory. The motor is back on correct rotation but the pump is still pushing excessive oily moisture and consistently tripping the thermal overload for the motor.

What is the potential internal damage to my pump, and would this pump be a good candidate to be rebuilt? Or am I better off replacing it with a brand-new pump? The pump is an Atlas Copco (potentially rebranded Chicago pneumatic?) Model# 1312100706. Rebuild kits do exist at roughly half the cost of a replacement, but I want to be sure the damage is not to extensive to rebuild. Can anyone give me some advice? I'm guessing I need to start by tearing down the pump, but I don't know exactly what I'm looking for here.

Thanks in advance for any help you guys can send my way!

 

[5ubtle]

I believe that some pump designs could run backward or forward with no difference.

 

[Steve_P]

I don't know the answer, but in order to have any success in trying to get $ from your utility company, you're going to need to get something in writing from the compressor pump's manufacturer stating it will damage the pump, not someone on GJ.

 

[jdtreeline]

I don't know the answer, but in order to have any success in trying to get $ from your utility company, you're going to need to get something in writing from the compressor pump's manufacturer stating it will damage the pump, not someone on GJ.

I’ve all but given up on any compensation from them. I’m just trying to fix my compressor so we can resume some projects in the shop.

 

[Steve_P]

I’ve all but given up on any compensation from them. I’m just trying to fix my compressor so we can resume some projects in the shop.

Then you know the answer.... time to tear down the pump.

 

[Dagny]

If the big pully has fan like spokes you would not have air moving over the compressor properly but I dont think thats really important unless your sand blasting and have very long run times.

 

[Olafur]

The type number points to Chicago Pneumatic CA1

Two Stage CA1 Bare Replacement Pump for Chicago Pneumatic, NAPA, and BelAir Reciprocating Compressors

The C1 bare compressor pump is a full cast iron reciprocating compressor pump. The internal factory part number for this pump is 1312100706 and may sometimes be shown as 1312-1007-06 or 1312 1007 06.

www.portlandcompressor.com

Here is user manual for what looks like the same compressor, it even has part diagram.

https://www.compressed-air-systems.com/assets/downloads/technical/manuals/pump-manuals/CA1-CA1U-pump.pdf

In the troubleshooting section for: Excessive oil discharge in air (All Compressors have a small amount of
oil carry over in compression)

Worn piston rings or cylinder
Restricted air intake
Oil level to high
Compressor has exceeded it duty cycle

So the first order of business is to check if the air filter is clogged up or something else blocking the intake. Also check the oil level if too high.

Looking at the part diagram I don't see any oil pump. This thing is splash lubed (the pointy thing extruding from the rod bearing cap hits the oil; part #65 in the part list) and could possibly survive running backwards for years - or not. Impossible to say without knowing the unit. I don't. If the air intake is not restricted and oil level is correct you are looking for worn piston rings or cylinder if/when you tear it down.

 

[Muckin_Slusher]

I don't think that thing cares if the crank is forwards or backwards. The piston just has to go up down. I could be wrong though.

The pulley will still move air whether it's sucking or blowing.

 

[seber]

Other than the pulley fan, that pump would not care about direction of rotation. Blowing oil is a sign of normal wear. It may have been accelerated by lack of cooling air flow. Check the filter, then check cylinder pressure. Most likely you will need new rings. Hopefully the cylinder is not damaged. A cheap scope attached to your phone can tell you that. They are as little at $10 from China.

 

[jdtreeline]

Thank you guys for all the replies. The compressor definitely still pumps up to full pressure no problem. But if we are running it hard it will trip the thermal overload on the motor. We’ve been needle scaling a truck frame and when the compressor warms up, the thermal overload usually trips on the 3rd time the compressor tries to cycle. I’m going to look inside with a scope like seber suggested and go from there.

 

[cannuck]

the oil dipper #65 is VERY much directional dependent. You want to look at the rod bearings first, as they have been running with little to no lube since reversing. That probably makes complete replacement cheaper. You definitely have had a lubrication failure, thus the overload trip. The cylinders probably survived as excess oil on the dipper slings off onto the walls and it was probably still splashing enough around (if oil level was kept up).

 

[jdtreeline]

the oil dipper #65 is VERY much directional dependent. You want to look at the rod bearings first, as they have been running with little to no lube since reversing. That probably makes complete replacement cheaper. You definitely have had a lubrication failure, thus the overload trip. The cylinders probably survived as excess oil on the dipper slings off onto the walls and it was probably still splashing enough around (if oil level was kept up).

This makes perfect sense. Thank you!