1/0 service entrance feeders

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jute

jute

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SO CAL
Hi, I was called to give a bid on unfinished work on a remodel in progress... The house in question has (3) 1/0 aluminum se wires feeding a 100A main panel. Not alot of power considering there's a hot tub, 60A garge feeder (air compressor) and all the spaces in the existing main panel have been maxed out. Now they do a remodel on the back portion of the house and have an additional (6) 12/2 w/ grd homeruns hanging by the side of the main panel ready to connect and no where to go. These where ran by ??? The General Contractor wants me to upgrade the service to the largest size panel possible with the exisitng 1/0...I have 1/0 aluminum ug service lateral coming into a main meter/panel combo. Can I put a 125A meter/panel combo for upgrade and for the extra circuits assuming a 125A would hold everthing... Any suggestions?? Thanks, JB
 
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Who owns the underground portion?

Are they under the control of the utility?

The NEC will allow the 1/0 AL to supply a 125 amp home service. Table 310.15(B)(6)
 
iwire said:
Who owns the underground portion?

Are they under the control of the utility?

The NEC will allow the 1/0 AL to supply a 125 amp home service. Table 310.15(B)(6)
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I guess I should call and find out more but I thought everthing before the service (service wire included)?? belongs to the power co...Thanks, JB
 
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Actually, in the Detroit metro area, the service drop wires (from Detroit Edison) are usually about a #4 solid, and if you call them to request the larger service wires (for a 150 or 200 amp service), they will provide about a #1/0.
 
jute said:
I guess I should call and find out more but I thought everthing before the service (service wire included)?? belongs to the power co...Thanks, JB
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Around here, the POCO stops at the meter base.
The service entry conductors (from the meter to the main if seperate) are sized (per the NEC) and supplied by the Electrical Contractor.

Regardless...NEC 310.15(B)(6) allows 1/0 Aluminum to be used as Service entrance conductors and feeders on a 125A service.

steve
 
jute said:
Hi, I was called to give a bid on unfinished work on a remodel in progress... The house in question has (3) 1/0 aluminum se wires feeding a 100A main panel. Not alot of power considering there's a hot tub, 60A garge feeder (air compressor) and all the spaces in the existing main panel have been maxed out. Now they do a remodel on the back portion of the house and have an additional (6) 12/2 w/ grd homeruns hanging by the side of the main panel ready to connect and no where to go. These where ran by ??? The General Contractor wants me to upgrade the service to the largest size panel possible with the exisitng 1/0...I have 1/0 aluminum ug service lateral coming into a main meter/panel combo. Can I put a 125A meter/panel combo for upgrade and for the extra circuits assuming a 125A would hold everthing... Any suggestions?? Thanks, JB
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Sounds like to need to do a load calc. You gonna hang your license on a 125a service for the total load? The 1/0 al will meet code for 125a. The POCO will bring what ever they wish to bring.
 
Cavie said:
Sounds like to need to do a load calc. You gonna hang your license on a 125a service for the total load? The 1/0 al will meet code for 125a. The POCO will bring what ever they wish to bring.
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I found a Square "D" 120v/240v single phase 3 wire flush mount all in one Panel. I agree I need to do a load calculation, this house is occupied and I'd like to know any methods/suggestions on how to do this with minumum time inside the house?? Is there a way to I can estimate the loads on the branch circuits or do I need to trace each one? I also need to put together a parts list. I'm posting a pic(I hope it works) of the exisiting panel and would like to know the best way to go about doing this with mininum amount of downtime. (as in no power going to the house) I have a small portable generator if I need it but I think I can do this in a 8hr day? so the HO doesn't go without power.I've only done (3) panel changes/upgrades and any advice or order of steps to take to accomplish this is appreciated...Thanks, JB

PS Thanks to all for the help/info..As always, this site has been very informative and is always appreciated...
 
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I hope you haven't given a firm price :smile:
has all the smell of a GC "taking" a somewhat inexperienced EC, especially since you inherited the job. ever ask what happened to the 1st EC ?
You can probably do a decent enough load calculation to see if you are in trouble simply by taking into account the sq. ft of the residence and adding the other loads that you can identify by breakers. Exact, no, but it will give you an idea.
Once that is done and you have determined if the old service is adequate you can plan your job. New service vs oold service is going to be the key here.
 
jute said:
I found a Square "D" 120v/240v single phase 3 wire flush mount all in one Panel. I agree I need to do a load calculation, this house is occupied and I'd like to know any methods/suggestions on how to do this with minumum time inside the house?? Is there a way to I can estimate the loads on the branch circuits or do I need to trace each one? I also need to put together a parts list. I'm posting a pic(I hope it works) of the exisiting panel and would like to know the best way to go about doing this with mininum amount of downtime. (as in no power going to the house) I have a small portable generator if I need it but I think I can do this in a 8hr day? so the HO doesn't go without power.I've only done (3) panel changes/upgrades and any advice or order of steps to take to accomplish this is appreciated...Thanks, JB

PS Thanks to all for the help/info..As always, this site has been very informative and is always appreciated...
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8 HR is plenty of time to do this work. Do metering and grounding first. If the inspector comes early, this is what he wants to see. Use one of the optional load calcs in appendx e in the back of the book usinng you connected load. Don't sweat the small stuff like lighting. Use big stuff like ranges,dryers washer, pumps, heat, SABC, etc. After that is aded up you'll know if your lighting will fit in. Since you are in Southern Cal, buy the looks of that panel and thinking you have a good sized a/c load, I would think a 125amp service is too small. Don't worry about what to POCO brings you , that is thier problem. Just tell them what you are doing. They play by a different set of rules.
 
augie47 said:
I hope you haven't given a firm price :smile:
has all the smell of a GC "taking" a somewhat inexperienced EC, especially since you inherited the job.
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I agree, especially if it's me....I faxed a proposal to him with a firm price (nothing signed) and he called about 2 hrs later wanting me to include bringing the remodel portion up to code... I told him there's (5) circuits that are ran back to the panel that were ran by ?? to ?? and I would only be responsible for the panel being a code compliant installation. Any troubleshooting and/or labor other than that would be an additional charge.

augie47 said:
ever ask what happened to the 1st EC ?
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Yes, and he told me he was dead...I thought he was joking but he said he was serious??? (I asked him twice)...He also told me he worked for him for about 6 years and NO, I still don't believe him...
augie47 said:
New service vs oold service is going to be the key here.
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Agreed, hopefully upgrading to a 125A will do... (if you can call that an upgrade)...Thanks...JB
 
Cavie said:
Use one of the optional load calcs in appendx e in the back of the book usinng you connected load. Don't sweat the small stuff like lighting. Use big stuff like ranges,dryers washer, pumps, heat, SABC, etc. After that is aded up you'll know if your lighting will fit in. Since you are in Southern Cal, buy the looks of that panel and thinking you have a good sized a/c load, I would think a 125amp service is too small. Don't worry about what to POCO brings you , that is thier problem. Just tell them what you are doing. They play by a different set of rules.
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This is a UG service that comes from the front of the house located behind them... if the 125a doesn't cover it and I have to go to 200A? who usually pays for the new service wires?? POCO or customer? Thanks again, JB
 
norcal said:
Does SCE require a 3" conduit for 200A services per EUSERC? (If upgraded)
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Is this what EUSERC>>>Existing Underground SERvice Conductor???
If they did, is this part (before the Meter) of the POCO's scope?? This is in So CAl, (Fullerton) I'll be calling on monday to find out more...Thanks, JB
 
Just do a simple load calculation and find out if it will work. Get rid of the 1/0!I think it would be a great disservice to change it to anyting other than a minimum of 150amps even if they had all gas appliances. The equipment does not really cost much more.
 
jrannis said:
Just do a simple load calculation and find out if it will work. Get rid of the 1/0!I think it would be a great disservice to change it to anyting other than a minimum of 150amps even if they had all gas appliances. .
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I told the GC/HO (he's one in the same)that 100A>125A upgrade was almost like adding an extra breaker...I wanted to go with a 200A upgrade...He doesn't want to have it dug up from panel through his backyard and the backyard behind his and then along the side and out to the to the street to get new service wires...Thanks, JB
 
iwire said:
Don't you think the power company is going to be a bit upset if he gets rid of power company conductors? :wink:
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I was hoping they would be the one replacing them?? Then charge a disconnect and reconnect fee...In Glendale they ran larger OH Service wires and then charged a discoonect and reconnect fee of $450... Unless the customer got charged from the POCO that I'm unaware of???Thanks, JB
 
jute said:
Is this what EUSERC>>>Existing Underground SERvice Conductor???
If they did, is this part (before the Meter) of the POCO's scope?? This is in So CAl, (Fullerton) I'll be calling on monday to find out more...Thanks, JB
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http://www.euserc.com/

BTW, SCE should have a book of their requirements, PG&E calls it the "Green Book", that will give you a lot of info.
 
Cavie said:
Sounds like to need to do a load calc.
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I went to the property yesterday to label the wire and then I was going to do the load caculation so I'd be ready to swap the panel out after I heard from the poco....

Cavie said:
The POCO will bring what ever they wish to bring.
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The poco (meter spotter) showed up around 1:30 and I told her what my plan was and ask if I could go higher than 125A on the 1/0 service wires. She looked at the 1/0 and then went to look for the tranformer to get a distance and to see what kind of shape it was in. When she returned she stuck a label on it and told me when she got back to the office she'd do the load calculations and check the trasformer number, she then told me If I didn't hear back from her by the end of the day then I could do a 200A service and not worry about the wires only being 1/0... Thanks, Jerry
 
I'm going back there this morning to start this job and it's got 2" galvanized pipe coming up for the UG service... I need to lower the new panel about 8" but I'm not sure how I would go about shortening this pipe, It comes about 4' out of the ground and I need to cut off about 8" with the 1/0 service wires (still hot?) to lower the new panel... This will be the first time I have to do this and Any suggestions would be greatly appreciated..Jerry:-?
 
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