Older compressor, need some power advice

[MongoTom]

I just picked up a Quincy QR-25 series Model 310-101 that I won in a bid. It looks like a nice machine, 60 gallon tank, Baldor motor and even though it's 30 years old, I think it's what I've been looking for. I've spoken with people at Quincy and a local parts supplier and they've been amazing, supplying manuals and such.

There's only one real problem: the motor is 3 phase. So I'm asking for the best solution to this problem. Replace the motor or get something that will adapt it to run on my power? I know there are a few solutions for conversion and don't know which is best.

Also, is there anything I should do to determine the quality of the tank itself?

Thanks for the help!

 

[G_P]

What HP is the 3phase motor? Simplest solution is to just swap the motor for a single phase motor, but that will likely run several hundred dollars unless you can score a used motor for cheap.

As for the tank, look up hydrostatic testing.

 

[stratman977]

Since its a big tank you should be able to see inside through one of the openings. Take a look and see what it looks like and go from there. Most likely its probably either going to look good or youre going to know right away that you don't want to use it.

Not much has changed in the design of these tanks in the last 30 years.

 

[MongoTom]

The motor is 2 HP.

 

[stonesfan68]

The cheapest option is going to be a new, 230V/1Ph motor. If you're really worried about longevity of the motor then get a 3HP. You'll have to sort out a single-phase pressure switch, too.

 

[BLACK DEATH]

2hp seems low isn't it?

 

[wild cowboy]

2hp seems low isn't it?

nope

 

[MongoTom]

A friend is saying I could use a VFD like he did with his mill. I'm not sure that a compressor motor would work that way due to the large startup energy involved.

I would consider moving to a 3 HP with appropriate RPM, if that could be done without harming anything.

 

[wild cowboy]

higher HP is like larger wire, it doesn't hurt anything, you could put a 30 HP motor on it if it is the same RPM & pulley size!

 

[bsaint]

The cost of a VFD would be about the same as a single phase 2 hp motor. Just get the motor and keep the starter. Just change the heaters.

 

[rockwithjason]

A friend is saying I could use a VFD like he did with his mill. I'm not sure that a compressor motor would work that way due to the large startup energy involved.

I would consider moving to a 3 HP with appropriate RPM, if that could be done without harming anything.

it can work. the cylinders are unloaded at start up and you can configure most vfds to act like a soft starter.

 

[MongoTom]

Change the heaters? Sorry, don't know what that means.

I guess the advantage of converting power is that I wouldn't have to change anything like pressure switches and heaters and whatever else. There's some appeal to that. I'm looking for pro's and con's now. Thanks for all the input.

 

[bsaint]

Heaters = overloads. Must be an older term as most people don't know what I'm talking about but its the term my dad taught me and the motor house uses.

 

[tool_scrounge]

Change the heaters? Sorry, don't know what that means.

I guess the advantage of converting power is that I wouldn't have to change anything like pressure switches and heaters and whatever else. There's some appeal to that. I'm looking for pro's and con's now. Thanks for all the input.

If you use a VFD, you may need to rewire a a few things. All the VFD's I have seen are meant to be directly connected to the motor. No pressure switches, overload, etc in between. Otherwise you can blow up the VFD if you switch out the motor while under load. You could probably rewire the pressure switch to the VFD remote control input to turn on/off the VFD. The only possible issue may be some high power/high voltage switches may not be reliable when switching low voltage/low current signals. My guess is that the switch will probably work OK.

 

[sberry]

There's only one real problem: the motor is 3 phase.

Just a minor issue.

 

[MongoTom]

Yes, the VFD sales guy said the output can destroy switches and such and said I might need something else. A rotary phase converter? It sounds like I'm getting into more expense. I think a new motor that meets all the size requirements can be had for less than $500. I'll try to determine what other parts need to be replaced to make this thing work.

 

[tool_scrounge]

Or just build your own 3 phase converter. The simplest would be to find a used 5HP 3 phase motor to act as a phase converter and start it with a fractional horsepower motor (aka Pony motor). There is lots of info on the web regarding.

 

[032484]

craigslist is your friend. Look for a small cheap air compressor just for the motor. I found 2 years back a 10 gallon 2hp belt driven air compressor for $40. I bought it just for the 2hp doerr motor.

 

[tool_scrounge]

Unless you plan on having other 3 phase tools (mill, lathe, etc), finding a cheap 2hp single phase motor is probably the easiest. Put a wanted ad on Craigslist.

 

[MongoTom]

Sounds like a plan. Thanks!

 

[pepi]

Don't put the cart before the horse, check the tank ..