Vacuum Former Change from 3 phase to Single Phase

[the1toyplace]

I have been reading this site for years and thought maybe somebody could help me. I am not sure if I posted in the correct spot so let me know.

I have been vacuum forming for the last 4 years and have just recently bought a new machine. I bought a proto vac 200. I only paid $400 for it and I feel like I got a great deal. The only problem is it is a 3 phase and I only have single phase in my work shop.

I know I could hook it up to a phase converter but I do not know what hp I would need. I spoke with the manufacture and they said the machine could be switched to single phase 240v. They told me I would need to change the heating elements and put in a 240v switch. There are 18 heating elements and they said each element cost 100 each.

I have been doing some research and I have found similar elements for about 50 each. However, they look just like my elements and they do not say 3 phase.

Here are some of my questions. Do I really need to change out the elements? Is the wiring to the 3 phase switch anything special? I can give you more information, I just didn't know what you would need. I appreciate any type of help.

Basic Info on the Machine

AMPS 225, Volts 240, Cycle 60 Watts 9000

[Al_The_Man]

You need to know what voltage the present elements are, the only reason they use 3ph is for efficiency, the elements will run just as easily on 1 ph, but you may have to reconfigure the terminations, a schematic would help.
Al.

[Geof]

Heaters are a resistive electrical load so you cannot hook them up to a phase converter. That only works with inductive loads like motors.

But the heating elements themselves don't care if they are connected to single phase or three phase it just needs different wiring. It is possible that you could rewire the existing heaters for single phase. But to get the same heat output it would require a larger amperage supply than was used on three phase.

What you need to do is carefully draw out the existing wire diagram and post the drawing to get some feedback on whether it will be feasible to convert it.

[mike_Kilroy]

Basic Info on the Machine

AMPS 225, Volts 240, Cycle 60 Watts 9000

think someone was smoking funny stuff when they came up with those specs.....

let's see.....

225a*240v*1.73(for 3ph)=93,420 watts!

or 9000w/240v/1.73= 21.7 amps.....

might you have slipped and missed the little dot in between the 22 & 5?

[the1toyplace]

Thanks for the replies. When you say you need a drawing of the wiring. Do you mean for the entire machine? I checked and found the little dot between the 22 and five.

[mike_Kilroy]

lets continue.....
9000w/18pc=500watts each? on 240v 1ph that is only 500/240/1.73= 1.2 amps each..... seems mighty small....

you found equiv heaters so what are they rated? 500watts each?

so double check the basic specs so we have a better idea what ideas to offer maybe?

[Al_The_Man]

Thanks for the replies. When you say you need a drawing of the wiring. Do you mean for the entire machine? I checked and found the little dot between the 22 and five.

No, just for the elements, they probably were wired in across the 3ph to a star neutral?
Al.

[mike_Kilroy]

cool, found the dot. so that jives with 9000watts. 9000w is similar load to a 9000w/746w/hp = 12hp motor load. that said, any old rpc 1ph to 3ph converter would be tickled pink to run that machine. Not a vfd tho as it does need a motor hooked up, not resistors. so check out (google) "phase perfect converter" and start reading up here on posts about rpc (rotary phase converters). with a wiring diagram of the machine, it may be found that dave kamp's(spelling) capacitor feed to missing phase might even do the job.... but wiring diagram is something you should try to post for more ideas too.

[mike_Kilroy]

for another idea, would the machine work with 2/3's of the heat? 9000*2/3= 6000watts? maybe it could be run on just 2 of the 3 input wires.... again, wiring diagram would help see.... anything else on the machine other than those heaters?

[Al_The_Man]

As pointed out, you do not require 3ph (convertor or other) for heating element, if you ascertain the present voltage across each element, you should be able to reconfigure for 1ph.
You may have to beef up some of the wiring and/or current protection, but a schematic should clarify this, wired star or delta?
Al.

[the1toyplace]

I will work on drawing the wiring diagram. There are two sets of heaters. Top and bottom heaters. There is also a vacuum pump with a 20 gallon tank it empties. The frame is moved up and down by an air compressor. Is there a way to post pictures? There is a percent timer, timer and a value release on the front of the machine.

[Al_The_Man]

Is the motor 3ph?
If so you may be able to use VFD just for this?
To post pic, go advanced and an upload screen is available.
Al.