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Need help! Have 3 Ph 440 volt Pullmax need to run off single phase

Zmancustoms

Plastic
Joined
Jan 11, 2015
Hello everyone,

I have a Pullmax Nibbler I need to run off single phase in my shop. It has a 3 phase motor looks to be 2 speed from what I can tell. It has 2 separate hp ratings on the plate 5.5 hp and 6.5 hp. it is 440 volt 1720 rpm and 3500 rpm. I have been told to go the VFD route with a foot control for the variable speed. I am new to setting up this kind of thing and would really like to find someone in the Dallas Texas area to help. If there is anyone out there that wants to make some extra money helping me out that would be great. Also any information on how to go about doing it myself would be great. Can someone tell me what VFD I need?

Thanks in advance.
Zane
 
Single phase supply at what voltage in your shop? If you have 440 available there are VFD that operate off single phase but you have to look at the specs closely
to see if the VFD accepts single phase and at what derating. If you only have 230v single phase then at that motor power a 220 -> 440 transformer rated at about
5 KVA would be needed. DrivesWarehouse is located in Dallas and a phone call to them might be a start: https://www.driveswarehouse.com/t-contact.aspx

Here is a writeup on running HV motors on 220V: HowTo: 240V Supply to a 400V AC Motor - Application Detail Whether this would
suit is hard to know, but some derating is implied, some being at least 30%. IE the motor will run but only be good for 3-4 HP.
 
Zmancustoms, I'm told VFDs are expensive and they're down fall is they only operate one machine, If you ever come across another 3 phase machine you would have to buy another VFD.

If you buy what is called RPC Rotary Phase Converter, you can run multiple machines off the same phase converter.
RPC have been around for years, are very reliable which is a plus. I have heard some people say VFDs are new technology and dont have the longevity that a RPC phase converter have, ( However this is hear say, I myself have zero experience with the VFDs and am just relating what I heard while doing research for the RPC that I bought. )

There is also what is known as a static phase converter which are dedicated to only one machine, I have been running my 3 phase drill off of it for 10 years without any issues.

Depending on what kind of 3 phase machine you want to run they classify them as easy start which would be a drill press in which a static phase converter is perfect for.

Then you have machines that are medium start machines that a VFD or RPC would be better for. on machines like this you want to make sure the motor on your RPC is equal or bigger than the motor you are trying to start.
It would be advisable to make the phase converter motor a little bigger by at least 15-20%.

Then there are hard start machines, Things like machines that have hydraulic pumps such as a Lathe, shear, press brake. For machines like this you want the motor of the phase converter to be twice as big, in my case my shear has a 20 Hp motor so I went with a 40 hp motor on the phase converter.

Then you have a air compressor which is a really hard start so you need double the HP plus some.

As far as dealing with what we call 480 Volts which is high voltage, you have to buy a transformer to step up your voltage from 230 Volts to 480 V.

I'm sure there are a few things I missed in my explanation so others feel free to comment on any thing you feel I missed.

Regards. Keep in mind, I am not an electrician but have done a fair amount of wiring my own machines and conveyor motor swaps.
 
By the way, I ended up buying my phase converter from American Rotary, they sell different types, make sure you call them and let them help you size it for the type you need, for me I needed a soft start because I am close to not having enough power at the service.

Whether you buy from them or whoever, its cheaper to ask questions before you buy than ask questions afterwards.
 








 
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