On a print I recently received a print for a substation provided with 120/208 4-wire service. On the architects drawing they want me to provide a transformer turning this system into a 1-Phase 120/240V for the remodel of the two towers new heating system. Question is, I've never set up a system like this, not to common up here. Do they even make transformers like this?
Transformer?
- Thread starter wi-elec
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This is a state/ government funded job so i don't think money is that big of an issue, but the print calls for a 400A 1-Phase service on the exterior of the tower, fed from the transformer off the 120/208 4 wire main. 280A of total calculated load. Now if I buck boost the 208 to 240, I still need a couple of single pole 120 ckts.
I can't find a single transformer that will handle that load. About 30 kw (load) is the biggest buck/boost I find, but I'd check with a transformer supplier.
You might need to divide your load, however, since you say cost is not an object, Sqaure D makes a 75 kva 208/240-120 1 phase transf (EE75S60H), or even a 100 kva.
You might need to divide your load, however, since you say cost is not an object, Sqaure D makes a 75 kva 208/240-120 1 phase transf (EE75S60H), or even a 100 kva.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
If you need 120V loads fed from a panelboard do not consider a buck-boost. There is no clean and easy way to generate 120/240 1PH 3W from a buck-boost.
Go with a standard transformer like augie suggested.
Go with a standard transformer like augie suggested.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
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- Electrical Contractor
Not if you want to be able to bond the derived "neutral." :wink:
winnie
Senior Member
- Location
- Springfield, MA, USA
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- Electric motor research
I dunno about that. If you take a 120V:120V transformer, connect it as an autotransformer, and then drive one of the 120V coils with one of the 120V legs of your supply, then you will get a 120/240V single phase supply where supply grounded neutral remains the neutral of the derived 120/240V system.
*grin*
-Jon
richxtlc
Senior Member
- Location
- Tampa Florida
If you can use a pole mounted transformer as they are normally 120/240 centertapped.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
What part about this method do you consider clean or easy?:grin:
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