power converter

[anallisguy]

I hate to ask electrical questions, but here goes.
Received a new machine at work, along with a power converter that came with it.
Prior to the machines arrival, supplier told us that it required a 40 amp 120 line. Ran a #8, bought a single pole breaker,and
that parts ready to go.
Didn't know about the converter until it arrived. Took the cover off today and found 2 poles on each side.
I'm figuring that's correct and it will work, but I was expecting to find 3 poles on the output side, particularly since
the machine its powering has input posts for L1, L2 and N.
So just go with the flow so to speak and only use L1, L2?
PS. Yes its a Chinese machine, but don't lecture me. I'm with you on that subject, but I have to deal with the hand that's been dealt.
.
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[dr sportster]

So where are you getting a neutral for your machine?

 

[Stephen Newell]

I'm wondering what the converter does. Does it convert 220v to 110v such as with European power? What is the machine?

 

[anallisguy]

Stephen The converter is intended to convert the 40 amp 120v to 220/240 volts.
The machine is a cooling tunnel, used in food production. It has a refrigeration unit built into it.

dr- that's my question...

 

[JF in MI]

You may have a 'multi-input' type of transformer. We used to have those in the medical machines I used to test. When the install technicians set them up they would select the terminals matching the voltage for the country they were in.

 

[Steve@Advance]

If the transformer is used to boost the voltage, you will connect the 40a 120v line to either of the terminals marked 110, the neutral from the panel to the other 110 terminal. Ground the case.

That will give you 220v out to the machine. There will be no neutral. Continue the ground to the machine case.

 

[dr sportster]

I don't see it happening.

 

[Lucid]

I have to ask the question; why not run 220v service straight to the machine and skip the converter? I'd be knee deep in the machines manual before going either direction!

 

[Steve@Advance]

Lucid, I was wondering the same thing.

Suspect they want the floating neutral as a safety factor.

 

[Stephen Newell]

How do you get 220v on a single line without the converter though?

 

[John T]

Allis guy, I just don't have enough information to provide an answer (can offer educated guesses) so until you have more details and specs on that unit BEWARE of any answers here including mine !!!!!!!!! Based soley on the picture it appears to be a 120 in and pure 240 (NO 120 NO Neutral) out IE Line and Neutral in and L1 & L2 (NO 120 NO Neutral) 240 out. Here are my thoughts based on the limited info I have..........


It looks sort of like a simple step up dry transformer IE 120 in and 240 out, and it may be an "isolation" transformer.

Iffffffffffff that's the case ?? (I cant say from here) the 120 input is across the Hot and Neutral and Id connect the safety bare/green Equipment GroundING conductor to the iron case/frame. Then its straight 240 out L1 to L2, NO 120 out, NO NEUTRAL out.

NOTE absent a center tapped 240 volt secondary winding THERE IS NO NEUTRAL ON THE OUTPUT AND NO 120, ITS ONLY 240 LINE TO LINE.

NOTE if its a pure isolation type transformer, NOT an auto transformer, the 240 output IS FLOATING in which case its 240 line to line but zero volts with respect to ground and there's no Neutral either.

NOTE if your machine requires L1 & L2 and Neutral, it must use BOTH 120 and 240. If that's the case the output winding of a transformer requires a 240 volt winding that's center tapped so its 1/2 or 120 either line to Neutral but 240 line to line..

NOTE if your machine requires BOTH 120 and 240 that's 4 wires 2 Hots, Neutral, Equipment Ground BUTTTTTTTTT that would require a center tap in the 240 volt transformer which it doesn't "appear" you have BUT I CANT SAY FROM HERE

Theres yet other questions: You need to know if that transformer is configured as a "Separately Derived Source"

Sorry best I can offer absent details and specs and more info so consult a trained professional electrician or engineer before connecting so you don't smoke it grrrrrrrrrrrr. If the machine requires 240 Id just wire it to 240 and skip the 120 to 240 process UNLESS it requires isolation and floating for whatever reasons ???

John T Long retired power distribution design engineer so no warranty especially absent more details and specs and info.

 

[MarkB_MI]

I wonder if the requirement for 120 volts 40 amps was incorrect. Outside of North America and Japan, 220 is the norm. But if the COOLER ITSELF requires 110, the supplied transformer would provide the required 110V/40A power from a readily available 220V/20A line.

The cooler is probably intended to float from ground, and the transformer serves to isolate it from the incoming line. That significantly reduces the chance of electrocution by accidental contact with the a live conductor. It's commonly done with medical equipment.

 

[anallisguy]

Thanks for all the replys.
Some thoughts in response and updates:
- There is no manual. If there was, it would be in Chinese anyhow..!!
- I also wonder why not run 220 dirct and skip the converter.
- To do so, since I've run 8/3 to the machine, I would go back to the panel and remove my single pole 40amp brreaker
and replace with double pole, but not sure about the amps required for that breaker.
- I've asked the purchaser to contact the Chinese and ask the following:
The output on the converter that you supplied only has two posts.
Since they are not marked, and its a 220 on the output side, these posts
must both be hot (110 each), with no neutral.
But the input panel on the cooling machine has positions for L1, L2, and N (neutral).
If we only connect L1 and L2, is this correct? Does any portion of the machine
use 110? Without a neutral, I don't think this would be possible.

What is the purpose of the converter. Can we provide 220 directly to the machine
and not use the converter?

We'll see what they say.

 

[Frankinfl]

You need to determine the required voltage of the equipment. Common service voltages in China are 220v/440v 50 cycle. If this equipment was not manufactured for export it likely needs 220v. The transformer may have been included to allow use on 120v.If you just guess the majic smoke may be released. The standard household voltage is 120v/240v an is not 110v/220v.