600 amp res
- Thread starter normbac
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
A ct is a current transformer cabinet for the CT's that the poco installs on large services.
MLO -- Main lug only panel
MB-- Main Breaker Panel
- Location
- Massachusetts
CT = Current transformers, often used by the power companies for metering service larger then 400 or 600 amps.
MB = Main Breaker Panel
MLO = Main Lug Only panel
MB = Main Breaker Panel
MLO = Main Lug Only panel
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
brantmacga
Señor Member
- Location
- Georgia
- Occupation
- Former Child
here's a pic of a 400A CT service I've got to rebuild (adding panel, transfer switch, etc. . )
the gutter was put on top of the cabinet because a 4/0 SEU comes out of the wall going to a 200A panel; those u/g conduits feed a 100A panel and disconnect in the second picture.
here's the stuff being fed from the gutter
here's what it looks like now. panels are relocated to the outside to get them out of this crawlspace.
anyhow, maybe pic 1 will give you an idea. i'd stick the gutter under the CT cab extending out the side of it and nipple up to 200A discos.
the gutter was put on top of the cabinet because a 4/0 SEU comes out of the wall going to a 200A panel; those u/g conduits feed a 100A panel and disconnect in the second picture.
here's the stuff being fed from the gutter
here's what it looks like now. panels are relocated to the outside to get them out of this crawlspace.
anyhow, maybe pic 1 will give you an idea. i'd stick the gutter under the CT cab extending out the side of it and nipple up to 200A discos.
I have priced and installed the I-line panel and thought they were comparible in price to the cutler hammer exterior disconnect I use on 200 to 400 amp services. I usually have a choice of putting a CT cabinet on the house or taking the feeds directly to the x-former. In the latter customer pays for and maintains the service conductors to the point of disconnect. We are allowed 6' of condutors before 1st disconnect. I have always installed a M.B. but if you keep under six breakers I think you could use a 600 amp M.L. I line. I don't know why other than cost but the I-Line comes with 3 busbars but a single phase M.B.
cadpoint
Senior Member
- Location
- Durham, NC
- Occupation
- Electrician - but not by NC Law.
Why not:
CT cabinet (& meter panel)----->gutter----->2-200 MB & 1-250MB w/200 MB for their isolated (MLO) panel?
The 250 will be lightly loaded. ??
If its a POCO lateral, don't they will usually exceed any service size that will exist anyways?
- Location
- Massachusetts
All that does is raise the price without adding any capacity or spaces.
fisherelectric
Senior Member
- Location
- Northern Va
If the ampacity of 4/0 al is 180amps and you use the next higher breaker, why wouldn't a 200amp breaker be compliant for 4/0 al?
Last edited:
- Location
- Massachusetts
fisherelectric
Senior Member
- Location
- Northern Va
The load on the panel served by the 200amp disconnect and SER is what matters. What other problems?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
If we are talking about ser cable here and we are using the 08 code then 4/0 is only good for 150 amps
- Location
- Massachusetts
There is no way to dived up the 551 amps between the three panels in a way that none of the 4/0 would be overloaded.
Covering my rear, my code book is not by my side and I did not want my post to sound like the load was the only issue.
- Location
- Massachusetts
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
fisherelectric
Senior Member
- Location
- Northern Va
"If we are talking about ser cable here and we are using the 08 code then 4/0 is only good for 150 amps "
Ok, got it. They have really made it expensive to put in a 200a disco and remote panel now.
Ok, got it. They have really made it expensive to put in a 200a disco and remote panel now.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Fisher-- if you hit the quote button on the bottom right of the post that you want to quote then it will be blocked like your quote is in my post.
- Location
- Massachusetts
Yeah- that's likely huh....
Not in my area, but it certainly is in some areas, like 220/221's area. :smile:
- Status