Wire Size

[Sparky Joe]

I'm just a wireman(lu354 SLC), but am curious if anyone might now from experience what size wire you guys would pull to a typical underground 200amp service for a house?
And what size, or what if the service were 650' from the xfrmr?

[Koga]

we usually pull in 1/0 alu. 650' is a good run I would bump it up to something bigger.Like 2/0 or even jump to 350 if the load needed it.

Koga

[graybeard]

We use 4/0 for 200 amp u/g but at 650' might need 350 but then cust. would need a 400 amp mtr box.

[dirtdobber]

at 650 feet we would not run it that far. we limit the secondary service to 250 feet over that we put a tx in & thus shoten the service length. we install everything with 350 and use nothing smaller even in 200 amp meter cans overkill yes but trouble calls just about none due to load problems.

[graybeard]

How do you get 350 in a 200 amp mtr box? All the 200 amp boxs they use around here would'nt take 350. The cust. has to supply his own mtr box.

[ppd613]

I currently work for an underground company and if we run a service that long it would be 350. they make an underground meterbase where drop pipe is offset and will accept 350. might want to think about bringing in primary and setting a tranformer closer to the house (depending on your load)

[OLE' SORE KNEES]

That's along way there mister...might want to put in a switch cabinet with some old style secondary capicators halfway(joke) but would probably work.......4/0 is a mouthfull for most 200 amp lugs,any bigger would be asking for trouble ,also consider voltage drop for that distance, I agree with others here,might want to get tx. closer somehow, or re-route it ......as a rule.................The meter base size determines which size service conductor you need to purchase. Typical service conductors include:

320 amp panel = 2 runs of #4/0-4/0-2/0 AL USE (218 feet or less)
200 amp panel = #4/0-4/0-2/0 AL USE (218 feet or less)
350-350-4/0 AL USE (over 218 feet, but less than 341 feet),

[dbrown20]

Bop into any service center of your local pwr. co. and I expect they would be glad to give you some charts detailing their local requirements for wire sizes for services including overhead and underground. We used to have them available for electricians anytime. Most residential stuff is routine but some commercial requirements might have to be individually tailored and required the "expertise" of an engineer. dbrown20

[dirtdobber]

in a 200 amp can aint easy but works swells the can a bit. bust the shit out of your knuckles on a daily basis.

[hifihaxor]

fpl has 2 standard urd triplex sizes (for residential).. 1/0 with 1/0 neut, and 4/0 with 1/0 neut... i dont believe 350 is a normal option, but they may use it for an extra special case. normally if the extra capacity was needed theyd do 4/0 in parallel... fpl is horrible about overloading stuff... its common to see a 1/0 from a tx to hand hole feeding 2-4 houses of moderate size.. mind you this is the old days of direct bury xlpe cable..

for a frame of reference, in the dec. 1999 issuing of the distribution construction standards, theres a secondary urd cable loading table (on sheet UV-17.0.3 and UV-17.0.4, incase any fpl people want to look it up) with no regard given to length, ONLY to wet or dry conditions... (wet is defined as cables installed below the natural water line, which is about 8-10 feet in south florida) there is a small disclaimer at the bottom of the sheet that says "NOTE: current carrying capacity shown above is based on thermal limitations, anticipated load growth and voltage drop must be considered when selecting these cables"

heres part of the table (HDPE cable only, thats what we currently use):

1/0A TPX DIRECT BURY
Summer wet: 173a
summer dry: 150a
winter wet: 186a
winter dry: 162a

1/0A TPX 2" PVC DUCT
Summer wet: 129a
summer dry: 123a
winter wet: 136a
winter dry: 130a

4/0A TPX DIRECT BURY
Summer wet: 250a
summer dry: 217a
winter wet: 270a
winter dry: 235a

4/0A TPX 2" PVC DUCT
Summer wet: 192a
summer dry: 184a
winter wet: 203a
winter dry: 194a


2 CABLES IN PARALLEL 1/0A TPX DIRECT BURY
Summer wet: 260a
summer dry: 225a
winter wet: 279a
winter dry: 243a

2 CABLES IN PARALLEL 1/0A TPX 2" PVC DUCT
Summer wet: 194a
summer dry: 185a
winter wet: 204a
winter dry: 195a

2 CABLES IN PARALLEL 4/0A TPX DIRECT BURY
Summer wet: 375a
summer dry: 326a
winter wet: 405a
winter dry: 353a

2 CABLES IN PARALLEL 4/0A TPX 2" PVC DUCT
Summer wet: 288a
summer dry: 276a
winter wet: 305a
winter dry: 291a

and for reference:

350mcm A, XLPE, single conductor DIRECT BURY
Summer wet: 331a
summer dry: 287a
winter wet: 357a
winter dry: 310a

350mcm A, XLPE, single conductor PVC DUCT
Summer wet: 305a
summer dry: 291a
winter wet: 317a
winter dry: 303a

so possibly use that as a guide... a possible option, if you have to use a 200a meter can, run 350 tx to right before the meter and set a hand hole, in the handhole splice the 350 to some 4/0 and take the 4/0 in to the meter can... because the 4/0 is only a short section, it will handle rated current and there shouldnt be any voltage drop due to length... the 350 will account for the long run voltage drop.

ymmv, id like to know what the solution is.