goldie lox
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upgrading to a 400a single phase residental service, its an over head drop with 15 of wire needed from the weather head. what size wire will be needed.
400a service
- Thread starter goldie lox
- Start date
American Locomotive
Well-known member
You'd need 500 MCM wire at the minimum IIRC.
pattenp
Well-known member
Should be 400 kcmil copper or 600 kcmil aluminum for 400A service.
wyliesdiesels
Well-known member
Why 400a?
What are you running?
What are you running?
OP
goldie lox
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Two 200amp panels
wssix99
Well-known member
Adds up
'Cept 2-4/0 AL do not equal 400A.
wyliesdiesels
Well-known member
joe_padavano
Well-known member
The house that I used to own, a new build in 1987, had 400 amp service that was split from the meter into two 200 amp panels. Used two sets of 4/0 wiring. Yes, this was inspector approved. The trick is that the wiring needs to be EXACTLY matched in length, to avoid resistance differences from one side to the other.
And as for loads, this was a 4,000 sq ft house with two 12 ton heat pumps, well pump, electric water heater, electric stove, etc, etc.
And as for loads, this was a 4,000 sq ft house with two 12 ton heat pumps, well pump, electric water heater, electric stove, etc, etc.
Radix2
Well-known member
Exactly matched from the meter to each panel? What possible difference could it make? The current at each panel is complely independent, heck, you could shut one off...
sberry
Banned
Here is what I think. I have 400, I could have done 200 and not starved for power. It is a lot easier to disconnect completely for emergency. Also,, what is the goal, to use it or see how much you can use at once?
I have some demand, at the time put a big tig on but have a 3 hp walkin, 3 well, 3 air comp and a 5 pressure washer and there is a freak chance I could be drying a laundry. Even with a welder and a hoist would have real trouble hitting 100 and doubly hard to ever trip a breaker. I done it.
One of our guys here often comments,, I got all the stuff and never tripped a 70. In other countries they have incentives to minimize some. One of my goals today would be to keep to 200 if I could. This is not to the OP but just general in nature.
My ideal install today would be 200 underground to 200 meter base, to panel 8 space. maybe more outside and feed thru lugs to a panel inside.
I have some demand, at the time put a big tig on but have a 3 hp walkin, 3 well, 3 air comp and a 5 pressure washer and there is a freak chance I could be drying a laundry. Even with a welder and a hoist would have real trouble hitting 100 and doubly hard to ever trip a breaker. I done it.
One of our guys here often comments,, I got all the stuff and never tripped a 70. In other countries they have incentives to minimize some. One of my goals today would be to keep to 200 if I could. This is not to the OP but just general in nature.
My ideal install today would be 200 underground to 200 meter base, to panel 8 space. maybe more outside and feed thru lugs to a panel inside.
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sberry
Banned
Mine ***** cause I have 2 panels but all the outbuildings are subs from one and all the equipment inside on the other, they really would be ideally different so they could be backfed together under a single disconnect for e power. There is a tendency to want to shut both mains down and use a suicide cord to jumper them together. I have 3 or for subs, the well is on one.
wyliesdiesels
Well-known member
People almost always think they "need" more power than they really do.
OP have you done a load calc?
Many PoCos require them before they will upgrade a service.
Usually upgrading to a 400a service requires the transformer and service wire to be swapped.
OP have you done a load calc?
Many PoCos require them before they will upgrade a service.
Usually upgrading to a 400a service requires the transformer and service wire to be swapped.
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It's a residential service, we get to use the 83% rule. So parallel 4/0 AL is fine.
PoCo probably won't change a thing, unless you really to have a ton of load. I think most 400a services around here are fed by a 25KVA transformer (good for about 100a continuous) and 2/0 aluminum pac.
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OP
goldie lox
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why do i need to do a load calc. i need to have to two 200 amp panels, one in a house and one in a 60x120 out building. so from what some of you say i should just keep the 200a in the house and run a sub panel into the outbuilding ok lets see. normal house elec heat heat pump ac with garage and garage stuff being used.
now outbuilding heated floors, hot water heater, welder, two air compressors, small lift ect....
ya let me just run the 200a panel with a 60a sub
now outbuilding heated floors, hot water heater, welder, two air compressors, small lift ect....
ya let me just run the 200a panel with a 60a sub
Just because you have 2-200a panels does not mean you need a 400a service.
I've wired many farms and acreages and it is common to have a couple 200a panels plus a few 60-100a panels all on one 200a service. If you add up the rating of all the panels it might come to 6-700 amps, but it is perfectly fine since most of the time the total load is well below 200 amps.
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mike93lx
ALLIANCE MEMBER
you certainly can throw money at the problem, but the point is that if you actually engage your brain, and do a load calc, you can appropriately size the feed for your needs.
nothing you listed justifies a 400a service.
that's serious power that makes sense for a commercial building or a very large house with very large air con and all electric appliances.
wyliesdiesels
Well-known member
Its all about load diversity.
yes a load calc is a great idea.
Will this shop have only one person working in it? If so, then you can only run so many tools at once.
Whats the HP rating on the air compressors?
What size welder?
As said above, 2 200a panels doesnt automatically equal 400a service.
You could put a 200a panel out there but still get by with 200a service.
SO yes do a load calc...
Have do the load calcs in order to use the rule, which is not sinking in with the OP.
You seem a little defensive about people asking a legitimate question trying to help you.
Like others have said above, its doubtful you need 400a of service. You can add up all of the stuff you'd normally use in a house and its not going to be that much power. Not everything runs at the same time.
Even in your shop. Unless you are running multiple people with some big equipment (mill, lathe, etc) you don't need 200amps out there either. My barn has 60 amps fed off my house 200a service and there are no issues. I can run my table saw, air compressor and probably welder at the same time with no issues.
sberry
Banned
My 400 is fed by a 15kva.
wyliesdiesels
Well-known member
15KVA is about 63a @ 240v.
How do you know its only 15KVA?
Whats the highest current youve pulled continuously?
Is this trany dedicated to your service?
If you pull too much youll blow the cut-outs on the pole.
Transformers are almost always labeled unless it really old and the numbers faded. For example a 15KVA will have a "15". Same as street lighting, they have a numbered, colored tag to indicate type and wattage. A yellow 40 means 400w hps.
They are ALWAYS undersized compared to what we as electricians are used to. But the utility's know most residential and farm services are not heavily loaded and the transformer can handle short peaks. Rule of thumb is an oil filled transformer will hold a 200% overload for 3 hours with no damage.
wyliesdiesels
Well-known member
yeah i know they are sometimes labeled. My loco PoCo has transformers that are labeled(the pole pigs any way- pad mounts are a different story) but PG&E and other area PoCos often dont have transformers that are labeled.
200% on a 15KVA is not even close to 200a so 15KVA for 400a is a bit undersized.
OH_Varmntr
Well-known member
sberry
Banned
Yes, it's labled, I was there when they installed it. I am not sure what my high would have been, I doubt 100 for very long. Not counting starts it might hit near that for a few minutes.
The duty cycle on thev walkin can be fair in hot weather, 50 percent , 30a, maybe and i run the well continious at times, 15 run, electric dryer but its not on high, pressure washer, welder, both intermit. Lights only a little.
There is really no drop in the conductors, got big fat short wire.
The duty cycle on thev walkin can be fair in hot weather, 50 percent , 30a, maybe and i run the well continious at times, 15 run, electric dryer but its not on high, pressure washer, welder, both intermit. Lights only a little.
There is really no drop in the conductors, got big fat short wire.
It's not uncommon to see a 25kva trans feeding half a block of houses, as long as none of then have a bunch of electric heat or something like that. I have put an amp clamp on quite a few residential services, many of them 200a, and it's rare to see over 30-40 amps even for short bursts. Continuous load is even less.
Back to the OP, it would help us if you could tell us what your loads are. Just have 2-200 amp panels does not in any way mean you need a 400 amp service. Services are sized by LOAD, not adding up breakers.
Back to the OP, it would help us if you could tell us what your loads are. Just have 2-200 amp panels does not in any way mean you need a 400 amp service. Services are sized by LOAD, not adding up breakers.
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sberry
Banned
Ya, about 85 peak. I had to really turn one up to see 70 and that was microwave and a toaster oven on. Electric water heater and dryer running. Both those are intermittent.
My bud had an overload on a 60 fuse panel. Electric appliances, 3 kids, bought a new micro and it jammed it up. I saw it to a 200 in a tavern, it had a LOT of stuff on it and I mean a lot. 4 fryers, ac, coolers, couple microns all side open on hot night. A period about 3 hours once a week a few times a year. This was before modern lights.
Had a broaster, coffee pots, 3 coolers, couple fridges. The fryers and the broaster were real 50A appliances.
I put 400 base, added another 150 panel, moved some load. Forgot ventalation, another 10 for that maybe more.
My bud had an overload on a 60 fuse panel. Electric appliances, 3 kids, bought a new micro and it jammed it up. I saw it to a 200 in a tavern, it had a LOT of stuff on it and I mean a lot. 4 fryers, ac, coolers, couple microns all side open on hot night. A period about 3 hours once a week a few times a year. This was before modern lights.
Had a broaster, coffee pots, 3 coolers, couple fridges. The fryers and the broaster were real 50A appliances.
I put 400 base, added another 150 panel, moved some load. Forgot ventalation, another 10 for that maybe more.
mtwaterguy
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Whats evidently not sinking in is that the OP asked what size wire for the installation, not whether he needed the service or not.....
Lots of good discussion here as to what is needed.
But maybe the issue is about wants, not needs.
If the OP wants a 400 amp service just for the bragging rights, I would not judge him for that as it is his money.
I myself have been looking for an excuse to run multi-mode fiber to my detached garage, which is about 10 feet from my house. Maybe somebody here can help me with that.
But maybe the issue is about wants, not needs.
If the OP wants a 400 amp service just for the bragging rights, I would not judge him for that as it is his money.
I myself have been looking for an excuse to run multi-mode fiber to my detached garage, which is about 10 feet from my house. Maybe somebody here can help me with that.
Perhaps you could explain that a bit.
A load calc will tell us what size service we need, but it doesn't determine whether we can use the 83% rule.
In this senario we have a 120/240v residential service,
We could say the load calc gives us 190A, and we install a 200A service. 310.15(B)(7) lets us use a wire that can carry at least 83% of 200A (166amps). 4/0 AL is good for 180 amps and can be used here.
Now if this were a business or commercial service things are a bit different,
Say the calculated load is the same 190 amps. We could install the same 200A service, but we no longer meet the rules of 310.15(B)(7) so we can't use it. Now we would need to use 250mcm which is good for 205 amps.
This same thing will work for a 400A service also.
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wyliesdiesels
Well-known member
Actually, that did get addressed in the first few comments.
But if a few of us wanted to make sure he really needed that size service and it turns out he doesnt, whats wrong with helping the OP save some money that could be used on more tools or something else...
Some PoCos will not upgrade service WITHOUT a load calc.
The only reason, in your situation for fiber, would be to isolate the garage for lightning suppression...
What was your reasoning for wanting it?
sberry
Banned
It would have been a short thread then, ha
No reason, other than it would be a cool project.
ard
Well-known member
Also, OP needs to understand that when *he* installs a '400A' service, the POCO will nod their head in agreement, but then install whatever size service supply they, IN THEIR SOLE DISCRETION, decide is needed.
This usually means they do some default load calc for a residence and garage and size it accordingly.
He will put in a 400A service, but I bet they will serve it with 200A or less.
Unless the owner provides the POCO with even a rudimentary (and/or inflated to the worse case, fully built out with every future bell and whistle) load calc that shows the poco 'if you go too small this may turn into a cluster- better upsize it'
This usually means they do some default load calc for a residence and garage and size it accordingly.
He will put in a 400A service, but I bet they will serve it with 200A or less.
Unless the owner provides the POCO with even a rudimentary (and/or inflated to the worse case, fully built out with every future bell and whistle) load calc that shows the poco 'if you go too small this may turn into a cluster- better upsize it'
Falcon67
Well-known member
>It's not uncommon to see a 25kva trans feeding half a block of houses,
Three drops off our pole, xformer is a 50K off a 7500K line
Three drops off our pole, xformer is a 50K off a 7500K line
sberry
Banned
I asked about the baby ****** when they did mine, they said,,, if it's an issue we will come back with a 25. It works fine on my end, I can't see lights flutter with air comps. I have small air pump as my main. Only time I ever ran anything larger than really 40A was a tig well over 15 yrs ago. I got used to living on rural power, everything i own is single phase 50A or less.
In the long run itvwas probably good, would have another whole collection of stuff I really don't use although I might have spun in other biz if I had convenient line power.
I would have loved it for irrigation, V8 engines being a pain in the azz.
In the long run itvwas probably good, would have another whole collection of stuff I really don't use although I might have spun in other biz if I had convenient line power.
I would have loved it for irrigation, V8 engines being a pain in the azz.
yucholian
Well-known member
My electric company just ran 350kcm aluminum for my 400amp upgrade