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#206660 07/29/12 05:34 PM
Joined: Apr 2002
Posts: 7,333
Likes: 7
With the parallel fuses, what would the amperage rating of this disco be??

[Linked Image]

(larger pics in Photo Area)

Last edited by HotLine1; 07/29/12 05:35 PM.

Joined: Jul 2004
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2x the size of the fuse ... nominally. The fuses have to be very closely matched for it to work that way.

Greg Fretwell
Joined: Jun 2004
Posts: 1,273
1200A Frame Size...

The chassis to neutral bond is striking as is the apparent lack of any dead front assembly.

The bus separation is consistent with 208Y120 voltages...

The neutral is sized to carry only an unbalanced fraction of the return current; hence its reduced cross section.

Just an eyeball hunch.

Joined: Apr 2002
Posts: 7,333
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The building this was the main for was gutted in Feb '03, a little over 2 months from when I took this photo. The line side of this 'main' (buss thru back to xfr vault). 'Vault' was determined to be POCO owned, with pots that had a PCB issue. BTW, it was a FPE disco, and the fuses seem to be 'original equipment.

We had many discussions on the rated capacity of the parallel fuses. This being the only one I have come upon.

Tesla, yes it is 120/208 Y, and I think it dates back to the early 1050s. Occupant was a two story, department store that was the original occupant of the bldg.

The electrical distribution, panels, & majority of the wiring looked like '50s, except the IG panel for the POS equipment.

Alas, it was all gone; I found this pic in my files. Posted it to get some discussion going.

Joined: Mar 2007
Posts: 404
That's some pretty advanced technology for 1050... I would have expected an oil distribution system to be par for the time.

Joined: Apr 2002
Posts: 7,333
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OK, ya got me....should be 1950s!! Sorry guys, that is what happens when you don't proof read.


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