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#134914 - 12/06/02 07:10 PM How do I do it Safely?
electure Offline

Member

Registered: 12/24/00
Posts: 4226
Loc: Fullerton, CA USA
I work with a couple of manufacturing companies that have home bases out of the US.
We've added 480x380,etc. transformers and odd buck/boost transformers (autotransformers) to spots as needed for the occasional odd voltage (here 277/480Y, 120/208Y are our nominal voltages).
I now have been "elected" to find a way to supply 100 volt power.
Does anyone have a source for this?
I only need about 30KVA, but I'm at a loss for the 100v 60Hz power, as the transformer doesn't seem to be available here in the US, and the manufacturer, in Japan, hasn't responded.
Thanks..S


[This message has been edited by electure (edited 12-07-2002).]

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#134915 - 12/06/02 09:36 PM Re: How do I do it Safely?
Bjarney Offline
Moderator

Registered: 04/10/02
Posts: 2561
Loc: West-Southern Inner-Northeast ...
Must the 100 volts be one 2-wire circuit? At 30kVA, that is 300 amperes. Safely designed maybe, but not cheaply.

Could the 100-volt load be split into 3 parts? That could reduce material costs some.

What is the acceptable voltage range for the nominal 100-volt equipment? Is a ~104-volt nominal acceptable?





[This message has been edited by Bjarney (edited 12-07-2002).]

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#134916 - 12/11/02 04:22 PM Re: How do I do it Safely?
electure Offline

Member

Registered: 12/24/00
Posts: 4226
Loc: Fullerton, CA USA
Yes, Bjarney, a voltage of 104 is acceptable, and a 3Ø system would be fine!
The circuits will be be used for industrial process equipment. We're supposed to install a few of the branch circuits now, and the bulk of the capacity is to be used for future expansion. (I've not even seenany of the equipment.)

[This message has been edited by electure (edited 12-11-2002).]

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#134917 - 12/11/02 10:17 PM Re: How do I do it Safely?
Bjarney Offline
Moderator

Registered: 04/10/02
Posts: 2561
Loc: West-Southern Inner-Northeast ...
At http://www.federalpacific.com/literature/drytrans/FPTS-RTB-0701.pdf page 12, you could possibly use a 120:16V 5kVA {SB16N5F} transformer. that would buck 120V to 104V at 313 amperes. Else, if the “30kVA” feed was 4-wire wye, you could use three 2kVA {SB16N2F} transformers, each connected on a per-phase basis.

For 2-wire 120-to-104 volts connect 120V and 104V neutrals paralleled to H2/H4, with the 120V “hot” to H1/H3 and X1/X3, and 104V “hot” to X2/X4.

Use one 2kVA transformer for each 208Y/120V phase terminal.

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#134918 - 12/20/02 07:07 PM Re: How do I do it Safely?
electure Offline

Member

Registered: 12/24/00
Posts: 4226
Loc: Fullerton, CA USA
Bjarney,
Thanks! I hadn't even thought about bucking this one down with autotransformers. Now they'll have their 104/180Y panel.
Now what colors am I going to use for that one? (Only kidding, but heck I've about run out!)
Thx...S




[This message has been edited by electure (edited 12-20-2002).]

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#134919 - 12/20/02 08:13 PM Re: How do I do it Safely?
Bjarney Offline
Moderator

Registered: 04/10/02
Posts: 2561
Loc: West-Southern Inner-Northeast ...
Been thinking about phase colors...how about puce, salmon and burnt sienna with a putty neutral?

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