[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.

[the1toyplace]

It has a fuse box. Is this what you mean by motor?

[Al_The_Man]

It has a fuse box. Is this what you mean by motor?

You mentioned vacuum pump?
1ph or 3ph motor?
Al.

[mike_Kilroy]

didn't u say mfgr offered new heaters for running this whole machine on 1ph??

why not try to take them up on it?? ask them to send you a rewiring diagram or instruction sheet how to change it over and see what they say!

[the1toyplace]

They said they could sell me new elements and they said call an electrician and he could rewire. The elements would cost at least 1800 for them. I didn't want to spend that much if these elements are fine.

I was looking at the wiring. The elements are wired to one another. I think they called it a daisy chain. I will have to look better. Then they are all wired into a device. The device says 1, 2, 3 on it. The elements are wired into one side with white wires. The other said has 3 black wires coming out.

Those black wires are then wired into what looks like a breaker box. I am still working on the pictures and a diagram. I think the pump is 1ph. I am moving some boxes around to get to it.

We just moved. What a pain.

[Al_The_Man]

It sounds as if they may be wired star connected to neutral, in the absence of a schematic some reverse engineering is required to determine exactly?
Essentially elements are single phase devices, they just need the required voltage to operate.
The other factor is if they are switched in progressively in banks for different level control?
Does the supply requirement indicate straight 3 ph only? or 3ph and neutral?
Al.

[the1toyplace]

I do not care if the heater turns on using the panel. Is it possible to wire the heating elements to a single phase 240 on off switch and then run that wire to a breaker to my garage panel? I would also have to wire the pump the same way. I do not need the percent time to work.

[Al_The_Man]

You are going to need either the schematics or do some reverse engineering, in lieu of that, get someone with electrical experience to analyze the present set up.
Al.

[mike_Kilroy]

They said they could sell me new elements and they said call an electrician and he could rewire. The elements would cost at least 1800 for them. I didn't want to spend that much if these elements are fine.

I did not mean to BUY the replacement heaters, but with them telling you to hire an electrcian to wire the new ones in, that means they should be willing to send you a 1 ph wiring diagram! push them. tell them your electrician said he NEEDS A WIRING DIAGRAM in order to give you a firm quote for the work. tell em "so please send me the wiring diagram so I can see if my electrician can do the work and give me a price so I know how much this will cost me. without that missing info, I cannot decide if it makes sense to spend the money on the new heaters or not."