What's new
What's new

All in 1 transformer advise requested 480v to 240v transformer and reversing

Bondo

Hot Rolled
Joined
May 14, 2011
Location
Bridgeton NJ
I am in need of specific advise for purchasing a transformer. I have talked to local electricians and I dont get any responses because im assuming companies dont want to do odd things.

What I would like to do is purchase a 480v Y to 240v D transformer that can power 30 amps of 240v (single or 3 phase welder) and also have the possibility of using a 110v stick/tig welder at 20 amps.

I would also want to be able to reverse wire this transformer to power 480v equipment like conveyors and misc machinery at my shop. Which has a 3 phase RPC at 240v D. I have 2-30 hp RPC connected together.

My goal is to be able to have 480v at the shop to test machinery and to have 240v in the field when we are 20 feet away from 480v or 300 feet from the truck/240v power source.

I have read plenty of articles on the web about reversing transformers, and I see what I need to do. But I want to make sure I buy the correct item first since transformers and not returnable once out of packaging.

Sent from my SM-G960U using Tapatalk
 
I am in need of specific advise for purchasing a transformer. I have talked to local electricians and I dont get any responses because im assuming companies dont want to do odd things.

What I would like to do is purchase a 480v Y to 240v D transformer that can power 30 amps of 240v (single or 3 phase welder) and also have the possibility of using a 110v stick/tig welder at 20 amps.

I would also want to be able to reverse wire this transformer to power 480v equipment like conveyors and misc machinery at my shop. Which has a 3 phase RPC at 240v D. I have 2-30 hp RPC connected together.

My goal is to be able to have 480v at the shop to test machinery and to have 240v in the field when we are 20 feet away from 480v or 300 feet from the truck/240v power source.

I have read plenty of articles on the web about reversing transformers, and I see what I need to do. But I want to make sure I buy the correct item first since transformers and not returnable once out of packaging.

Sent from my SM-G960U using Tapatalk

If you can HAUL it, (I can load it for you..) from near Dulles Airport back to New Joisey, I can give you a 15 KVA one that "might" do:

CAVEAT: "Delta" both sides, and an all-copper premium-grade "eliptical-coil" unit intended for uber-long life in utility service.

Read: "heavier than than the usual 15 KVA." Close to 400 lbs, IIRC. Premium-grade and special-order/custom-built is what Pennsyltucky-based R.E. Uptegraff do and for getting close to a hundred years, already:

R. E. Uptegraff Manufacturing Co.

Needless to say, the 15 KVA rating is conservative! It should easily deal with the typical loading of welding operations with less heat-rise than the average 15 KVA.

Email me thru PM's email feature if interested. My "PM-PM" inbox is always full..

Bill Hacker
 
The reversing issues (aside from UL or NEC rules) tend to be a matter of the turns ratio being adjusted to compensate the voltage for drops due to current,

That I HAVE seen but only in smaller units below 1 kVA. Once up above 10 kVA, I would not expect to find that. I do not suppose any functional issues are likely in reverse connection.

I have in fact seen small transformers that were very different in reverse.... they had higher voltage out in step-down, falling to normal at rated current. When reversed, the lower turns ratio made them much lower than might be expected as far as output voltage. They were 500 VA or so, as I recall, some lower.
 
Hi John!

Hmmm... yeah... after re-reading your description a half-dozen times, then checking out your website, it sounds like you're not so much integrating the transformer into your shop or system, as you would be transporting it around and connecting it up as-needed for whatever purpose you came upon.

That being the case, Bill and Tiers' suggestions are about as close as can be had.

The reason why your local electricians and utility guys are hesitant to answer, is because there's lots of variables, unknowns, and lots of things to go wrong, coupled with liability issues, they're gonna keep out of the scenario as much as possible.

If YOU understand what you're doing, there's no reason why you can't do it, aside from violating your utility company's rules, or moreso, violating the laws of physics.

It sounds like, to me, you need a little 4x4 utility trailer chassis, with Bill's 15kva, and a couple of utility panels, a couple safety switches, and some cord-reels, a variety of electrical sockets, and add on an overhead light... for a towable multi-tool.

I don't have to do things like this anymore, but back when I was playing in a band that opened for very large groups, our stage companies used just this type of setup for providing power to portable stage systems for outdoor performances. One of the stage companies had a trailer with a multi-tap 100kva transformer, and a flip-up 'pole', and a meter socket. They'd tow that in, unhook, and screw down 'jacks' with soil anchors (augers), flip up the pole, and call the utility company to set it up for site power. The output was 480v 3ph, which fed step-down transformers mounted in the chassis of the mobile stage system... everything had adjustment taps, but the only one they ever had to adjust, was the main one at the pole...
 
"What Dave said".. and the stage and sound lighting experience highlights ANOTHER issue.

How and from whence yah gonna FEED this rig, even once built, and how rapidly can you GET a power-source?

I'd be able to tow my MEP-803A along and already have 15 KVA, peak, off the Diesel, 208 Wye at the panel, adjustable by governor to 220 V Wye and a bit.

That rig is NOT for sale!

You can still have a free transformer, though!

All it is doing at present is helping hold a concrete patio down against wind gusts...

:)
 
The local electricians wont even hook up 3 phase to my shop. I agreed to the price that the local power company wanted to bring in 230v 3 phase and 3 different local electricians gave me quotes for installing new panels. They just want to do the job. Why I don't know when I'm throwing cash into the air, they are just walking away. I didn't even argue the price. 3 phase lines are only 400 feet from my shop. And 3 years now I still can't get anyone to run it.

My machine shop buddy can't get electrical work done either. Everyone just sucks around here. And he has a 60hp water jet he has to run off single phase.... and he does.


If miller or Lincoln would make a damm portable 3 phase welder, like the passport, I would have to do this shit. I already have a dynasty so stick and tig are simple, but mig on a boom lift, isn't possible with a 350p lol




Sent from my SM-G960U using Tapatalk
 
The local electricians wont even hook up 3 phase to my shop. I agreed to the price that the local power company wanted to bring in 230v 3 phase and 3 different local electricians gave me quotes for installing new panels. They just want to do the job. Why I don't know when I'm throwing cash into the air, they are just walking away. I didn't even argue the price. 3 phase lines are only 400 feet from my shop. And 3 years now I still can't get anyone to run it.

My machine shop buddy can't get electrical work done either. Everyone just sucks around here.

Unless.. your shop.. and your mate's shop.. are such sore-dangerous hovels - fire Marshall or zoning-edge-cases - to push for avoiding such an install on OTHER grounds?

That sounds VERY MUCH as if there are known (in the trade..) issues with your County Inspectors. Those'll cause credentialed commercial sparkie experts to be seriously risk-averse.
 
Oh it's probably way more screwed up then that. The power company has no problems installing a 3 phase run for a farmers irrigation system, but wont run certain business stuff.

Doesnt help that my county, Salem County, has the highest foreclosure rate in the whole country.

The worst part is I had cash ready for the complete install and still didn't give a shit. So that is why we have to do the odd things just to have what we are supposed to be available to.

I know if I build a new building, I will get a discount on it with the machinery layout, but I dont want a new building for another 5-7 years.

Sent from my SM-G960U using Tapatalk
 








 
Back
Top