220 single phase to 480 3 phase?

invisabledog

invisabledog

Active User
Registered
Joined
Nov 20, 2014
Messages
96
220 single phase to 440 3 phase?

Found an awsome deal on a pedestal grinder. Problem is it's 480 3 phase, so the owner thinks. I haven't seen it yet. Can this be made to run from 220 single phase with the right transformers and or convertors? I'm hoping when I see it, the data plate is there and I'm lucky enough that it may be a dual voltage machine.
 
Last edited:
Most every medium voltage three phase motor is dual voltage. You should be able to rewire the motor leads for 240 volt and get a phase converter or vfd. If it is 480 only, this would be a deal breaker for me as the required hardware would be prohibitively expensive.


Sent from my iPhone using Tapatalk
 
Turns out its 440 not 480, but it's not 220/440. I did buy it, it was a good deal. Basically paid scrap price for it.
 
I don't think it wise to put the transformer between the VFD and the motor, so you would need a 220v primary 440v secondary, single phase transformer, and a single to three phase 440v VFD. If you are diligent on eBay you may be able to get said items for a reasonable price.
 
Eddyde said:
I don't think it wise to put the transformer between the VFD and the motor, so you would need a 220v primary 440v secondary, single phase transformer, and a single to three phase 440v VFD. If you are diligent on eBay you may be able to get said items for a reasonable price.
Click to expand...

That's what I was thinking. Not being much of an electrition, I need to figure out what exactly I need for a transformer.
 
First use a transformer to step up the 220 to 440, you can size it based on the motor's horsepower, 1 HP =746 watts, so add a little safety factor and figure 1kva of transformer per 1 HP of motor and you will be fine.

Other note here, there is no difference between a step up transformer and a step down transformer, you just need a transformer with a 220v (or 240v) winding and a 440v (or 460v or 480v) winding

Next comes the drive, there aren't any 480v single phase input drives, so don't bother looking for them, however most (most meaning that there are a few drives that you cannot disable the phase loss detection that won't work) 480v 3 phase input drives will run fine on single phase for what you are doing, but you must oversize the drive by about double so that the rectifier section in the drive will be heavy enough to carry the motors current on just one phase, so buy a drive that is rated for twice the horsepower of what the motor actually is.
 
PJRitz said:
First use a transformer to step up the 220 to 440, you can size it based on the motor's horsepower, 1 HP =746 watts, so add a little safety factor and figure 1kva of transformer per 1 HP of motor and you will be fine.

Other note here, there is no difference between a step up transformer and a step down transformer, you just need a transformer with a 220v (or 240v) winding and a 440v (or 460v or 480v) winding

Next comes the drive, there aren't any 480v single phase input drives, so don't bother looking for them, however most (most meaning that there are a few drives that you cannot disable the phase loss detection that won't work) 480v 3 phase input drives will run fine on single phase for what you are doing, but you must oversize the drive by about double so that the rectifier section in the drive will be heavy enough to carry the motors current on just one phase, so buy a drive that is rated for twice the horsepower of what the motor actually is.
Click to expand...

So for a 2hp 440v motor, I need a 2kva 220 to 440 transformer and a 4hp drive?
 
my 2 cents,

don't waste the time, money or energy trying to step up your voltage.
replace the 440 motor with a 230v motor.
(like this)http://www.ebay.com/itm/2-HP-ELECTR...585?pt=LH_DefaultDomain_0&hash=item3f3abebdb9

if you find a 230v 2 hp single phase motor, your problems will be small.

if you try to go the hard way you'll wrap up a lot of money quickly and you'll have lots of exterior circuitry

i can help you find a motor if you wish to go the single phase motor route.
let me know how i can assist, i'm glad to lend a hand.
mike:))
 
I agree with the majority here, look into replacing the motor, preferably with a single phase model, or with 240V or dual-voltage, 3 phase. I bought a Sheldon lathe that ran on 480V, 3 phase, after I checked it out [& noticed that there was no info tag on the motor but assumed that it was dual voltage]. After I brought it home & opened the motor pot head I discovered that there were only 3 leads! The motor had an integral 4-speed gearbox so replacing it wasn't practical; I ended up buying an RPC & a used 6 KVA open-delta transformer. I think these, plus a NEMA size 2 starter, push button switches, enclosure & shipping cost over $1K plus wire, sealtite, conduit, etc., needed to hook it all up.
 
You must log in or register to reply here.
Back
Top