Someone with GOOD experience please suggest best placement of dual 200-A main breaker panels behind an outside 400A meter base. A contractor friend wants me to wire a residential structure he is about to construct. I have put in 200A services but never a 400A. Please suggest best methods and also things to watch out for.
400A 1-phase Service Equipment placement
- Thread starter oldchap
- Start date
- Status
masterinbama
Senior Member
- Location
- Huntsville Alabama
What is the footprint of the house? Last one I did I set a 2/200 400 amp meter main and set one panel for all of the HVAC and misc power on that end and set one on the far end for the Kitchen/ laundry room and bedrooms..
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
you would only be able to set them separate if you use a disconnect. 230.72
the mains have to be grouped
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
You can buy a meter main combo. This unit has a meter base and 1-200 amp breakers to feed to interior main lug panels.
I am old school and still like setting a 400 amp meter base (320 continuous) with a 200 amp wp feed thru panel on both sides. These panels have lugs to feed the interior panels as well as about 8 spaces to feed ac units, pools, sheds etc without having to go to the interior panels.
Many of the contractors in this area like Dennis' plan.
The "feed-thru" panels at the meter give are often handy for nearby equipment and the outside mains give them versatility on interior panel locations.
One fairly common adaptation is to feed the HVAC from one of the panels with a 100 amp branch feeding an interior panel farthest from the service.
The other panel feeding larger loads and close-by loads.
The "feed-thru" panels at the meter give are often handy for nearby equipment and the outside mains give them versatility on interior panel locations.
One fairly common adaptation is to feed the HVAC from one of the panels with a 100 amp branch feeding an interior panel farthest from the service.
The other panel feeding larger loads and close-by loads.
masterinbama
Senior Member
- Location
- Huntsville Alabama
We have to use a 400 with 2-200 amp breakers built in here. Since we are stuck with using only 2 90's from the street to the house, most people don't want a lot of equipment hanging on the outside on the street side.
400A 1-phase service question
400A 1-phase service question
Masterinbama, thanks to you and others for helpful suggestions. As for the footprint, I haven't actually seen the blueprints yet. My grandson who is the electrician I will be working with has seen the foundation and says the 4000 sq. ft. structure will be rectangular but nearly square. I'm not yet sure whether the 4000 is for the main floor size or includes the area of the 2nd floor. We are promised a print pretty soon and then I'll know. Maybe today the POCO engineer will find time to return my call so I will know his particular requirements.
400A 1-phase service question
Masterinbama, thanks to you and others for helpful suggestions. As for the footprint, I haven't actually seen the blueprints yet. My grandson who is the electrician I will be working with has seen the foundation and says the 4000 sq. ft. structure will be rectangular but nearly square. I'm not yet sure whether the 4000 is for the main floor size or includes the area of the 2nd floor. We are promised a print pretty soon and then I'll know. Maybe today the POCO engineer will find time to return my call so I will know his particular requirements.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
If, by "behind," you mean back-to-back behind the meter, a simple pair of nipples would do, or even SE cable, with the meter straddling the space between the MB panels.
There should be no problem using factory KO's, unless your local power co. has KO-use restrictions.
I put mine in a corner so the working space overlapped. Was kind of forced into that though because of where the riser had to go and a window taking up too much space on one wall.
I think two panels side by side with nipples into the back of the meter base is cleanest. Only other design issue is how you want to handle the GEC -- run one large one from a common point in the meter (if allowed) or from a gutter below the panels, or run a smaller tap between panels.
I think two panels side by side with nipples into the back of the meter base is cleanest. Only other design issue is how you want to handle the GEC -- run one large one from a common point in the meter (if allowed) or from a gutter below the panels, or run a smaller tap between panels.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Mark 250.64(D) allows 3 methods, and (3) is of the one you mentioned, where you can connect ahead of the service disconnecting means.
If you chose (1) or (2) you only have to size per 250.66 to the service entrance conductors supplying that enclosure for the taps, but the main GEC has to be sized for the main service conductors.
If you chose (1) or (2) you only have to size per 250.66 to the service entrance conductors supplying that enclosure for the taps, but the main GEC has to be sized for the main service conductors.
jmd445
Senior Member
- Location
- Hamilton Twp., NJ
Could some of you post pictures of your intallations?
Jim
Jim
- Status