Can 2 XRMERS feed same panel?

I have a 600A panel 120/240V. The largest xfmer I have found to step down

277/480V three phase to 12/240V single phase is a 167KVA (347Amps). Can I use two 167KVA xfmers to feed this panel?

Please email me at snipped-for-privacy@ventur.net.

Thanks in advance for your help. Vick

Reply to
watt
Loading thread data ...

Check your calcs.

167kVA @ 240V = 695A

--s falke

"watt" wrote...

Reply to
s falke

No you can not use two transformers to feed the panel. Check with your supplier for a larger one. A 167.5 KVA is a standard transformer. There are much bigger ones available.

Reply to
SQLit

Reply to
watt

It seems almost derelict to serve a 144kVA load single phase.

--s falke

Reply to
s falke

How would you do it?

Reply to
phil-news-nospam

He probably has no choice now, but designing it from scratch the loads should have been distributed somewhat evenly on the three-phase system. Here are two options:

1) If the loads are all 120, or capable of operating on 208, use a 208/120 3-phase panel and a 208/120 Y secondary on the transformer.

2) If you need 240 volts, split the loads onto three individual 240/120 panels on separate 240 volt transformers, one on each phase. Or use option

1, and a small 240 volt transformer where needed.

There are probably other ways also. It depends on the nature and size of the loads.

Ben Miller

Reply to
Ben Miller

My preference would be for #2 based on experience seeing A/C motors burn out when trying to run on 208 volts ... until they finally got a 208 volt motor (special order) in it (why it couldn't use a 3 phase motor I am not sure, but it may have been a wiring issue). Other 240 appliances, if present, might not work as well, such as electric stoves, kilns, etc, not functioning at the level intended (e.g. slower to heat up to temperature).

The catch is #2 is more expensive at the transformers. But the panels can be a lot cheaper because costs start to go up fast after the 200 or 225 amp level (if you have 600 amps of load, this could be the way to go). I've not worked out the pricing, but maybe I should do that and see (since I've downloaded both the Cutler-Hammer and Square-D catalogs).

Reply to
phil-news-nospam

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.