From: Fred Martin (mung@in-touch.net)
Date: Sat Jul 12 2003 - 05:39:02 PDT
The last time I put 3 phase in a bldg., it was the four wire delta
system...120, 120, 208 (wild leg) and a common. As I recall, years ago a
nameplate on an electric motor might read 110, 208, 220 volts. Haven't
seen it for a long time though. Fred Martin
Ryan Gill wrote:
> At 1:54 PM -0700 7/10/03, Horrocks, Aaron wrote:
>
>> While I have no experience with military AC/Heating units, I can tell
>> you about the juice needed for it!
>>
>> For 60Hz here's the standards:
>>
>> Voltage Phase Wires
>> 120/240 1 3 Used commonly in homes, small business
>> 120/208 1 3
>> 120/208Y 3 4
>
>
> Isn't 120/208 based on it being off of a 3 phase system (4 wires total
> at the box?) 208 volts being the sum of 2 hot wires that are 120° out of
> phase. Home 120/240 involves 2 hot wires that are in phase and yielding
> a total sum of 240 volts.
>
> How do you get 120/208 off of a single phase system? Isn't it by
> default, off of a 3 phase 4 wire system?
>
>
>> 240 3 3 " " pumps
>> 120/240 3 4 " " small business
>> 277/480Y 3 4 " " industrial
>
>
> 277/480 is useful for large installations of flourescent lights. Most of
> the floor on CNN center I'm on has 277 based lights.
>
>>
>>
>> 208 volts is one of those funky voltages that (pardon the pun) should
>> be phased out!
>
>
> Hardly, at home in residential, three phase is unusual. What you get off
> the pole is single phase. In industrial/Commercial applications 120/208
> is the lower voltage component of 277/480. My electrical room for the
> Data Center I run has two types of panels for my Data Center. 120/208
> and 277/480. The
>
> Perhaps the question here is if that generator is labeled as 208 and is
> really 208Y (perhaps no difference, one label is more particular than
> another?).
>
>> Usually 208V equipment is cheap because few manufacturers support it,
>> and most
>
>
> Its standard for computers, UPS and other applications in the tech
> industry.
>
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