Customer wants an upgrade from 200 to 300 amp service. This is for a single family residence. Is the easiest way to change there 200 amp panel to a 300 amp panel ( do they even make one for residentil)and sub feed the 100 amp panel they want, which will be about 100 feet away. They are not upgrading because of demand they believe the house will be worth more when they flip it . I have done many upgrades to 400 amp and grouped the two 200 amp panels together. thanks
200 to 300 amp service
- Thread starter 101010
- Start date
- Status
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Around here the POCO wants a load calculation before they will upgrade from a 200 to a 300. There may be an issue with the POCO if you can not show that you need more than 200 amps.
quogueelectric
Senior Member
- Location
- new york
320 service
320 service
The next step up from a 200 yet not quite a 400 which requires a trans s cabinet is what is called a 320 residential service I dont know why it is called a 320 when it is esentially a pair of 150s in parallel it should be called a 300. Traditionally these 300 amp res services are installed in the high number of 3000 to 4000 sq ft victorian houses built recently usually on 2 acres in our area the locals call these house tracts McMansions. Old potato fields sold to developers. It provides 2 150 amp 40 ckt pnls usually underground 350 alluminum monmouth cable to the meter then 2 sets of parallel 150 rope to the 2 150 panels. The water pipe ground must be a #2 solid bonded to either panel and the second panel must have the ground bugged outside of the panel usually right above where the #2 enters the adjacent panel that is how we do it on long island. Do expect to produce a load letter though to get LIPA approval.
320 service
The next step up from a 200 yet not quite a 400 which requires a trans s cabinet is what is called a 320 residential service I dont know why it is called a 320 when it is esentially a pair of 150s in parallel it should be called a 300. Traditionally these 300 amp res services are installed in the high number of 3000 to 4000 sq ft victorian houses built recently usually on 2 acres in our area the locals call these house tracts McMansions. Old potato fields sold to developers. It provides 2 150 amp 40 ckt pnls usually underground 350 alluminum monmouth cable to the meter then 2 sets of parallel 150 rope to the 2 150 panels. The water pipe ground must be a #2 solid bonded to either panel and the second panel must have the ground bugged outside of the panel usually right above where the #2 enters the adjacent panel that is how we do it on long island. Do expect to produce a load letter though to get LIPA approval.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Some areas require a CT cabinet for 400 amp services. CT= current transformers. These devices read the current being used on larger loads.
Aorund here we use the 320 amp meter base for a 400 amp service. A 200 amp is rated 160 amp continuous and 200 non continuous. A 400 amp base is the same 400 amp noncontinuous and 320 continuous.
In your situation you can just add a 100 amp panel and use the 320 amp or what I call a 400 amp meter base.
Aorund here we use the 320 amp meter base for a 400 amp service. A 200 amp is rated 160 amp continuous and 200 non continuous. A 400 amp base is the same 400 amp noncontinuous and 320 continuous.
In your situation you can just add a 100 amp panel and use the 320 amp or what I call a 400 amp meter base.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
If you are unfamilar with this type of installation, the first thing I would do is contact the POCO, you will need to conform to their standards. They will give you the info you are probably looking for, try to get it in writing, especially if this is your first time performing this type of installation.
What I should have said is the house already has a 200 amp main breaker panel and the home owner added a 100 sub panel about 100 away. If they wanted to change to a 400 know I would just have to add another 200 amp panel next to the existing and ground accordingly. In nj you need a ct cabinet for over 400 amps. So my question is should I just leave the 200 amp panel add a 150 amp next to it ,change to meter to 300 ( if they make one) and feed the 150 amp panel ,Then sub feed to the 100 amp? Would the feed for the 150 amp panel have to be the same size as the 200 or can I size it for the 150 . Sorry for the moronic question but i do mostly commercial. Does a 300 meter have double lugs?
What about switching your meter/main out to a 320A "all in one". These usually have one 200A main with lugs for a feeder (in this case, you'd feed your existing 200A panel I believe), and a 2nd 200A main feeding a small built in loadcenter (about 24 spaces ). Add a 100A breaker for your remote panel, and now you have room to grow. You also don't have to worry about changing out your existing panel breaker, etc..
Mike
Mike
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
101010 said:
I have never seen a 300 amp meter base.
They do make a 320 amp continuous meter base that is, in our area, good for a 400 amp non continuous load. Almost all our house with this meter base use 2- 200 amp panels. And YES, they have double lugs.
You said that in your area if it is over 400 amps you must CT but what about 400 amp--- if you can do that fine otherwise I don't see how they will let you use a 150 amp main with a 200 amp already there--- that's usually equivalent to a 350 amp service. A 150 amp main breaker panel cost more than a 200 amp panel in our area because no one uses a 150 panel.
So--- use 1- 200 with this non continuous 400 amp meter base or use this same meter base with a 100 amp main panel and then feed the other 100 amp sub panel from there. (this is in addition to the existing 200 amp panel)
quogueelectric
Senior Member
- Location
- new york
320
320
so that is where the 320 comes from it has baffled me for years and when I asked about the grounding at a lipa main HQ they all looked at me like I bit thier toe. The easiest way I could see to comply in my area is to change the main to a 150 in the existing panel and add another 150 next to it. SERVICE RATED BELOW 600 VOLTS
5.4.1 Service equipment shall include provision for metering transformers when load currents of
any one customer will exceed or 320 amperes for single phase or 200 amperes for multiphase,
see Section 8.
320
so that is where the 320 comes from it has baffled me for years and when I asked about the grounding at a lipa main HQ they all looked at me like I bit thier toe. The easiest way I could see to comply in my area is to change the main to a 150 in the existing panel and add another 150 next to it. SERVICE RATED BELOW 600 VOLTS
5.4.1 Service equipment shall include provision for metering transformers when load currents of
any one customer will exceed or 320 amperes for single phase or 200 amperes for multiphase,
see Section 8.
quogueelectric
Senior Member
- Location
- new york
300 amp
300 amp
Why dont you just go to electric design and construction at the power company they will be happy to help you provided you are a legit contractor.
300 amp
Why dont you just go to electric design and construction at the power company they will be happy to help you provided you are a legit contractor.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
I'd advise talking to the guy at the supply house, see if they stock or can order a 300A meterbase, and compare the cost with a 400A meterbase. I'd be willing to be the 320/400 meter enclosure is more readily available and darn near the same cost.
As others have said, talk to the POCO and AHJ and see what is allowed in your area. Here we would install a "dual lug" meter base and run two sets of entrance conductors. One would go to the existing 200-amp panel and one would go to a 100-amp disconnect adjacent to the existing panel. You would then install a feeder to the new sub-panel.
Alternatively you may want to perform a load calculation on the house to show the homeowner how little power they are actually using. The 300-amp upgrade may be totally uncalled for.
Alternatively you may want to perform a load calculation on the house to show the homeowner how little power they are actually using. The 300-amp upgrade may be totally uncalled for.
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