Auxiliary cooling fan

Futbalfantic

Well-Known Member
Joined
Aug 5, 2006
Location
Charlotte
I just bought a new to me drill press with a 3ph motor. I plan on putting a VFD on it. I've read that those motors can run at virtually 0rpms but the limiting factor is cooling. It's said "put a fan on it" and you're good to go. Here in lies the problem. I can't find any fans and don't even know what to search. Any help?
 
Does that mean "put a fan nearby to blow on it"?

If you want to do a full retrofit, remove the shaft-driven fan from the motor, and mount a 120V muffin fan (looks like a big computer fan) with a shroud to the motor. At some operational points, VFDs can put a lot of high frequency energy into the motor windings, which isn't used to turn the motor and gets dissipated as heat from the winding resistance. That's a problem because the shaft fan on the motor isn't doing much cooling at low RPM.
 
im leaning towards a retrofit but from what I had read was more along the lines of install it inline with the built in fan
 
Without an inverter duty motor you will a) not be able to drive it as slow as you think b) will definitely overheat the motor if you try and c) will have almost no torque. You should have plenty of usable rpm range though if you pick the right belt ratio and motor cooling probably shouldn't be an issue but as was said would be easy to mount a small enclosure fan to the motor, I would use a 220v fan and tie it into the vfd input somewhere.
 
I'm not 100% sure if it's inverter duty or not. Came out of an industrial shop and is a 220v/4??v motor not that means anything.

I want to be able to drive it that slow for large hole saws and what not and belts alone wolnt go that slow. Spindle speed is 230 at the slowest
 
Most likely it is not. What is the nameplate rpm on the motor? If it is say ~1800 rpm then you can easily run it down to 600 and up to 2800. Using that same pully ratio would give you ~75-400 rpm at the spindle using the vfd and keeping the motor happy.
 
You should not need any extra Cooling for that set up -- especially it being a drill press. You probably already know but since it is a dual-voltage motor it will be easy to make sure it is wired 240v, there will be a diagram on the nameplate or inside the peckerhead that will show you how to arrange the wires or terminals.
 
Obvious question but do you have 3ph power?

Also, slapping a vfd up there isn't as easy as it sounds. No offense, but it doesn't sound like you are super electically minded so you will need professional help getting a vfd set up properly. I work with vfd equipped equipment daily and I have my electricians or an engineer I use a lot set them up. That schit gets over my head quick.
 
I'm going to make another assumption and say he isn't installing a Siemens or AB powerflex but rather a simple china 220-240v ebay vfd and to be honest, he's not networking them, there's no braking resistor, safety or machine feedback and honestly at best it will hurt a $150 motor--wiring one is as simple as (and I'm also going to assume that he does not have three phase) a disconnecting means (plug) near the machine/drive, two hots and a ground into the input and three hots and a ground coming out. Don't really even have to worry about rotation as the drive will take care of that as well.
All that being said, if you're buying a china vfd and putting single phase into it you need to derate the "HP" by about half. Meaning buy a 2hp drive for a 1hp motor.
 
Going with this guy
TECO model L510-101-H1-U

120v 19amp at max / 220v 3ph output for 1hp motor

Yeah I'm not worried about rampup ramp down, soft start, syncing, etc etc etc. just want to be able to run 3ph and would be nice to have variable speed.

Not terrible worried about the wiring as @braxton357 said it seems very straight forward and nearly plug and play (hopefully I don't eat those words). Not highly sensitive components so shouldn't need shielding, EMF protections, and the what not (again hopefully don't eat my words on that too)

But back to the big question.

If inverter duty and can spin down to no RPMs I need a muffin fan and shroud.

What CFM should the fan be?
Are shrouds something I have to make or are there retrofit kits out there?

If not inverter duty, I'm looking at 600rpm motor speed minimum and I will not need a new fan for it?
 
You obviously know more about electricity than I initially thought you did. My apologies.

I wouldn't worry about the fan. Just put a cheap ass clip on walmart fan on it and roll. Unless you will be running it all day every day I don't see it being an issue. For hobby use you could likely get away for years with nothing at all.
 
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