Will this three phase transformer do the job?

My son has jsut bought a good sized NC router for use in his
manufacturing operation.
The new machine draws about 40 KVA maximum load and needs a 480 volt
three phase delta supply.
His shop has only 208 volt three phase Y power available.
This transformer on e-bay looks to us like it could be used to get him
the 480 volt delta supply he needs when driven by his shop power:
formatting link

I've never gotten very involved with three phase machinery power and
don't want to tell him to start bidding on that transformer (or similar
ones) without checking here on rcm to see if there's other important
things to consider when using three phase power transformers for this
kind of application.
Thanks guys,
Reply to
Jeff Wisnia
Loading thread data ...
It certainly appears to be suitable. Make sure it's located somewhere with adequate ventilation though, it could kick out a good deal of heat depending on the actual loading.
Pete C.
Reply to
Pete C.
Where are you at Jeff? I have a number of them
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Reply to
Other coast G.
Beantown, home of this year's (I hope) World Series winners again, the Boston Red Sox.
Reply to
Jeff Wisnia
Hmm ... first thing is that it is for 480V to 208V, not the reverse. Yes, it will work in reverse, but the voltage will probably be a few percent low.
Second thing -- have you calculated what the input current to the transformer from his breaker box would be? I figure somewhere around 150 amps at 208V three phase. Can his breaker box supply that much?
[ ... ]
Especially with aluminum wiring instead of copper. (That does make it lighter, but a bit less efficient.)
And I'm glad that *I* don't have to deal with shipping it. You're posting from snet, which IIRC is a Connecticut based network? The transformer is in Texas. That is a lot of shipping.
Good luck, DoN.
Reply to
DoN. Nichols
Hi, Jeff. We had to do the same transformer installation when we had to replace our old IR oven used to solder printed circuit boards. The new (to us!) oven required 480V. and could not be converted to 208V. The electrical company next door did the work. They had to derate the transformer about 20% when it was wired backwards. Works fine, but does get warm.
The transformer is connected to a 150A circuit breaker which we used as a switch to turn the transformer off at night and on weekends. One morning only 2 phases turned on. Turns out a fuse on the electric meter opened up. It is a quick-blow, silver fuse. Next week the same thing. So, the electrical company said to just quit using the CB to turn off the transformer. No problems since. The heat is nice in the winter, and not noticable in the summer.
I think the transformer cost us $75.00 plus shipping from Portland. There are lots of them available used and just laying around in elctric company warehouses. Don't buy a new transformer, they are quite expensive.
Good luck.
Paul in Redmond, OR
Reply to
This is an isolation transformer and will easily power your equipment. It is especially good since it can better withstand a bolted fault and survive. An auto transformer will not likely survive bolted faults. As for voltage adjustment this transformer has about 10% boost/buck capability.
Reply to

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.