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Buy it now or pass? Commercial compressor

I'll add my 2 cents also.
if you do work, and not just piddle around in your garage, then I would buy a screw.
if your a one man show with 1 machine, then no.

Once you've owned a screw compressor, there is no going back either.
I'll never buy a piston compressor again.

But you do have to look at your needs, compressor companies will even tell you this also, so.
you don't want a screw compressor unless you need it.

For a little bit more, you could get a single phase similar output system.
Atlas Compressor single phase.

remember also, you have to have a refrigerated air drier, you don't just need to buy the compressor.

Even on sale their expensive.
 
I sure as hell will. single phase motors SUCK. I've replaced probably a dozen start caps in 20 years.

A 3 phase motor on a VFD from single phase is a way better setup than a single phase motor, especially starting against a load like an air compressor.
Sure, but on a rotary phase converter it's the same deal.
I wouldn't bother modifying controls to add a VFD though. Just get something that runs on what you have.
 
I plumbed our air dryer between the compressor and receiver and it has been fantastic. As long as you have an aftercooler on your compressor it is worth it to always have a dry tank, and never run the risk of overdrawing through your dryer.
 
Sure, but on a rotary phase converter it's the same deal.
I wouldn't bother modifying controls to add a VFD though. Just get something that runs on what you have.

I don't follow you at all. Running your compressor through the same RPC as your machines is generally a really bad idea. Try it sometime.
 
Screw compressors really need to size matched to the air consumption. They don't last well in cycling mode as the oil never gets hot enough an end up accumulating moisture. Lot's of stories of screw compressor failures for this reason.

I recommend looking for a used oilless scroll compressor. Extremely quiet, as in I can barely tell it is running in my home basement shop when I am upstairs. These things require almost no maintenance, but have a consumable seal set that needs replacement at 10K hrs. That might be a couple decades in some shops or 2 years in others.

They also use a special bearing grease I am told should be replaced at 10yrs, but I have a 2006 unit running with only 900hrs on it I am thinking about doing.

So go hunting for one with low hours. I have bought 3x 5hp units with the most expensive by $1500. I did pay $5K for an unused 10hp with 200 gallon tank and desiccant drier.

This one is 3ph 460V, but is the sort of deal you want.
 
Geez, the OP is the same guy who wanted to know if there was any CNC without crunching numbers. Dude doesn't even have a machine that needs ongoing air supply. He needs something to blow off parts.

Buy a cheap compressor and move on. That compressor would be the most expensive piece of equipment in your shop.
 
I don't follow you at all. Running your compressor through the same RPC as your machines is generally a really bad idea. Try it sometime.
That's my point. Running off of an RPC puts you in the same boat as just having a single phase compressor. Both are capacitor start motors on single phase.
 
Usually these are coupled with receivers so that they don't run continually. A vfd sized for this unit would certainly cost more than starting a rotary as required!:ack2: If you actually see future capacity, then why hesitate?
Most screws are for hi use and run continious and just unload instead of stopping weather they have have a receiver or not.That one has a small built in one. We have 3 Kaesers like that on our offset presses. If your use is low enough that you have to start and stop then a recip may be your best bet.
 
Most screws are for hi use and run continious and just unload instead of stopping weather they have have a receiver or not.That one has a small built in one. We have 3 Kaesers like that on our offset presses. If your use is low enough that you have to start and stop then a recip may be your best bet.
Our 140CFM compressor has a 400 gallon receiver that it fills in around 4 minutes. I find that to be a pretty good sweet spot to keep the compressor happy and avoid short cycling for light loads. We do use the compressor at 90% capacity for extended periods when sandblasting, which is enough down time for it to periodically unload but never stop the motor.
 
We have 2 250hp's and a new 300 going into a 5k gal main receiver. They run alternately but continiously. The new GD has been through two motors and a control board in less than a year. What a pos.
 








 
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