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#116573 - 04/12/04 01:58 PM 1000 KVA Transformer.
iwire Offline

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
This is a service change that for the most part I did with one helper.

The building had a 4000 amp 208/120 service, we changed that to a 3000 amp 480/277 service.

We also added a 1200 480 volt switchgear almost 400' from the new service.

The original service had two 800 amp 208 volt feeders that fed two 208 to 480 volt transformers to feed some 480 volt refrigeration equipment.

My entire "print" for this job was an 8.5" x 11" paper one line diagram drawn by a VP at my office.

Key points.

1)Install new pad mount transformer outside and run conduit to a POCO substation.

2)Install new 480 volt 3000 amp switchgear

3)Refeed existing 4000 amp 208 service gear with 1000 KVA transformer

4)Run two 300 amp 480 volt feeds for refrigeration equipment.

5)Run 1200 480 volt feeder and install switch gear on the other side of building.

6)Reroute Fire pump feeder off of 4000 amp service gear and to another 208 service in the same area.

7)And as always little to no downtime, we did the cut over with 12 guys that worked 12 to 20 hours one weekend.

I wish I had pictures of the pipe work before the service gear arrived, I could not wait and did 99% of the pipe work before the gear was even on site.

Good cut sheets from Square D make that possible and when the gear arrived I punched and tipped it in under the raceways.


[This message has been edited by iwire (edited 04-12-2004).]
Bob Badger
Construction & Maintenance Electrician

Tools for Electricians:
#116574 - 04/12/04 02:04 PM Re: 1000 KVA Transformer.
big guy Offline

Registered: 12/19/03
Posts: 52
Loc: pa
good looking job

#116575 - 04/12/04 02:54 PM Re: 1000 KVA Transformer.
Electricmanscott Offline

Registered: 01/12/02
Posts: 1478
Loc: Holden, MA USA
Ok lets rip this one to shreds! Just kidding Bob, looks awesome!

#116576 - 04/12/04 03:56 PM Re: 1000 KVA Transformer.
electure Offline


Registered: 12/24/00
Posts: 4226
Loc: Fullerton, CA USA
Looks nice, Bob.
We're doing very much the same thing now.

2000A 208/120 existing.
3000A 480/277 new.

We're just going to refeed the 208 gear with a 500KVA xfrmr, the 120/208 load is not going to be that much.
I'll get some pics. You'll probably laugh when you see the meters on the front of the switchboards...S

#116577 - 04/12/04 06:05 PM Re: 1000 KVA Transformer.
Nick Offline

Registered: 08/13/01
Posts: 603
Loc: Riverside, CA
Nice Job Bob!
Gotta love that Square D gear.

#116578 - 04/12/04 06:23 PM Re: 1000 KVA Transformer.
Roger Offline

Registered: 05/18/02
Posts: 1779
Loc: N.C.
Very nice work job Bob.

One question though, did you guys carry the gear down those stairs?


[This message has been edited by Roger (edited 04-12-2004).]

#116579 - 04/12/04 06:47 PM Re: 1000 KVA Transformer.
CTwireman Offline

Registered: 02/07/02
Posts: 839
Loc: Connecticut, USA
Very nice.

You'll have to excuse my ignorance with this stuff, as I primarily do residential work.

Does that gear come as "some assembly required" or is it allready assembled? That stuff looks seriously heavy!! Square D has always been know for its robust equipment.

What size conductors are those hanging out of the switchboard?

What type of facility is this?


[This message has been edited by CTwireman (edited 04-12-2004).]

#116580 - 04/12/04 07:06 PM Re: 1000 KVA Transformer.
iwire Offline

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
That gear came as 3 sections, bolt together on site.

Yes it is heavy, those 3 sections together are probably 1100 to 1300 lbs.

The conductors hanging out are 3 sets of 600 kcmil copper to feed the 1200 amp switch gear.

The service conductors are eight sets of 500 kcmils for 3000 amps.

The 1000 KVA transformer inside was a little over 6000 lbs.

No I did not have to bring it down the stairs I did buy a 30 pack and give it to the contractor installing a large conveyor system (the reason for the 480 volt upgrade) the 30 pack gave me the use of his propane folk lift.

The forklift was tagged at 5500 lb capacity so the 6000+ lb transformer was pushing the limits, keep it low.

The outside transformer is close to 15,000 lbs and we opted for riggers to set it for us.

At the time this was a Dot Com home food delivery company, they went out of business.

The upstairs Tennant had 12,000 amps @ 480 (3 x 4000 amps) coming in from the roof along with a another 4000 amps @ 208 coming in near my work.

That tenant was all computers, they had enough generators to pick up all that.

[This message has been edited by iwire (edited 04-12-2004).]
Bob Badger
Construction & Maintenance Electrician

#116581 - 04/12/04 07:28 PM Re: 1000 KVA Transformer.
Bjarney Offline

Registered: 04/10/02
Posts: 2561
Loc: West-Southern Inner-Northeast ...
iwire—that looks like a mighty beefy drytype transfomer. Can you post the rated temperature rise? [Often 150, 115 or 80°C]

Assumedly it is 480∆ — 208Y?

Also, my congratulations. The stress and details of cutover work during a tightly scheduled outage always drove me nuts.

[This message has been edited by Bjarney (edited 04-12-2004).]

#116582 - 04/12/04 08:10 PM Re: 1000 KVA Transformer.
Ryan_J Offline

Registered: 08/19/03
Posts: 1355
Loc: West Jordan, Utah, USA
On the second picture from the bottom does the man door have an self-closer on it?
Ryan Jackson,
Salt Lake City

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