Hi, I am hoping some one has some pics of a 400 amp service they have done( and are willing to post). This will be my first one. I was wanting to come out of the meter can with two sets of 4/0 alum SE cable with side by side 200 panels directly behind meter can. All the pics i can find all have pvc or have a gutter put in. I was hoping to see how it looks before going ahead. Thanks
400 amp residential service
- Thread starter lucky1974
- Start date
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- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Depending on what code year you are on, seu may only be rated 60C so that is why you probably see conduit to the interior panels.
What we do is mount a 400 amp meter base and pipe to each interior panel. 4/0 is conduit is rated 180 so you have 360 amps available. Sometimes we just run 3/0 copper
What we do is mount a 400 amp meter base and pipe to each interior panel. 4/0 is conduit is rated 180 so you have 360 amps available. Sometimes we just run 3/0 copper
goldstar
Senior Member
- Location
- New Jersey
- Occupation
- Electrical Contractor
The last one I did was an under-ground service into a CT cabinet. I would check with your POCO to see what their requirements are.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Here is what the 2014 styates
Michael15956
Senior Member
- Location
- NE Ohio
Bumping an old thread rather than ask the same question.
I've got the exact situation. "400" amp service (the power company calls it 360 and 400 interchangeably).
Meter on the outside of the wall. A pair of 200 amp panels on the inside of the wall.
The code is rather confusing on what needs to be run. Does 4/0 exposed really cut it? Does it need to be in a conduit? At which point, why not just run copper in a conduit? It's going all of 4 feet. Not like a few feet of copper is a big expense.
I've got the exact situation. "400" amp service (the power company calls it 360 and 400 interchangeably).
Meter on the outside of the wall. A pair of 200 amp panels on the inside of the wall.
The code is rather confusing on what needs to be run. Does 4/0 exposed really cut it? Does it need to be in a conduit? At which point, why not just run copper in a conduit? It's going all of 4 feet. Not like a few feet of copper is a big expense.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
What do you mean by 4/0 exposed? Personally I would run conduit and use 3/0... You can use 4/0 aluminum however that is only rated 180 amps at 75C so you will only have a 360 amp service
kwired
Electron manager
- Location
- NE Nebraska
If you think you can't run aluminum conductors in a conduit you are wrong, most of the time you have to.
Sorry. One of those "I knew what I meant" moments.
SER in conduit vs out of conduit (exposed).
For service entrance in a residential application, would 4/0 not fall under the "next standard rating" and qualify as 200A in each feed?
mwm1752
Senior Member
- Location
- Aspen, Colo
If the inside 200 amp breakers are your service disconnect 230.32
kwired
Electron manager
- Location
- NE Nebraska
Can be protected with next size up which is a 200 amp device, but it's ampacity is 180 and the calculated load must still be 180 or less or you will need to increase size.
And this is why I despise reading the NEC. It says little and references itself ad nauseum.
Service conductors entering a building shall be installed in accordance with 230.6 or protected by a raceway method identified in 230.43.
230.43 says Service Entrance Cable is good to go....kind of. It says "Service entrance cable is ok if you use the applicable parts of this code".
230.6 seems to be irrelevant (determining if conductors entering a building are outside of a building?)
By that, exposed service entrance cable should be a-ok.
Of course, there's the "if subject to physical damage" caveat, which appears to be left to the whims of the individual inspector.
http://www.milbankworks.com/catalogs/u5890-5895.pdf
Check with utility and ahj, but I have used one of these (very similar anyway) for a 400A residence, to feed two 200A load centers. (if I recall correctly the one I used had one breaker on each side)
It's a Milbank 320 meter socket/combo with two 200A breakers
lol personally I have never seen a house pull over 70amps, and that's with everything going full blast trying to recreate a problem in the service entrance underground. I'm sure it can happen, but not in my little world so far.
kwired
Electron manager
- Location
- NE Nebraska
In areas with high electric energy rates, probably very few that aren't multi-million dollar mansions.lol personally I have never seen a house pull over 70amps, and that's with everything going full blast trying to recreate a problem in the service entrance underground. I'm sure it can happen, but not in my little world so far.
In areas with low electric energy rates electric heating is more of a popular thing. Right now you can probably heat a home less with gas, but a few years back when gas was high electric heat was less here.
I did a couple homes about 10-12 years ago now one has 45 kW of electric heating, two 4.5 kW water heaters, double oven, cooktop, dryer, well, hot tub, maybe a couple other items I have forgotten about.
Other home has 60 kW electric heating, 4- 4.5 kW water heaters, double oven, cooktop, three laundry areas with electric dryer in each, well, possibly other items there as well.
Both of those homes are fed by their own transformer as they are far enough away from other utility customers there is not going to be others on the same transformer. Both have CT metering right on the transformer and instead of running to a single 400 or 600 amp service disconnect both have multiple runs from the transformer, each landing in a 200 amp main breaker panel in the mechanical room of the house, cost of that was less then the single disconnect and would need the same main breaker panels as the end of feeder taps anyway had we gone with a single service disconnect.
Might have been able to squeeze the larger home on a 400 amp single service disconnect, but would have cost about same or even less then what I ended up with, and does have more capacity for extra down the road if ever needed. Guy did seem interested in a pool someday, and being a physician likely can afford it, - probably would be an indoor pool as well so more then just a pump and few other lower capacity loads.
readydave8
re member
- Location
- Clarkesville, Georgia
- Occupation
- electrician
not very unusual to have 3 heat pump w/ 10-15kw heat strips each, 2 water heaters, clothes dryer, electric range, etc.
So not very likely for all this to be going at the same time?
Well it is upon family's return from vacation
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
And, of course it sometimes takes us twice as many amps because of our choice of low voltage....
Not the case with line to line 240 heating elements or heavy duty motors.
On the other hand, for 120V applications we get two independent 400A 120V circuits for our 400A service, so I guess it does not really matter.
Not the case with line to line 240 heating elements or heavy duty motors.
On the other hand, for 120V applications we get two independent 400A 120V circuits for our 400A service, so I guess it does not really matter.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Very few. Ill bet more than 90% of homes that have a 400 A service dont need them. I have used a class 320 meter socket more times for the convenience of the dual lugs for a Pv interconnection or a 230.40 EX #3 situation than I have for a "400 amp service". I did some work in this house - it wasnt all that big, but high end - Had a 600 amp service, 3 200 amp panels. Stupid. They wanted more stuff connected to their generator. Seemed that it only ran a few lights and plugs despite being pretty big (something like 30KW IIRC). I took one of the 200 amp sets and just took them out. Bye, thanks for your 10 years of useless service. Took the next 200 amp set and spliced it to supply the three 200 amp panels. Took the last 200 amp set and ran it to a new panel that ran elec dryer, cooktop, heat pump, and a couple other largish things that I had pulled off the three original panels. Done. They were happy. Guess they had several electricians in there before me trying to get some more basic stuff on the generator, gears in the head churning looking at 75 breakers spaces of hardly no load....
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