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#209116 - 03/07/13 04:29 PM Does table 310.16 apply to primary feeds
bwise121 Offline

Registered: 09/11/03
Posts: 113
Loc: Sacramento, CA USA
I'm setting a 200 amp panel on a work shop and wiring in a few plugs and lights. The work shop is on a residential property and it is proposed to have it's own meter. According to the utility company it is automatically considered commercial. Which translates to the owner runs conduit and wires from the panel to the utility box at the street. Left for utility to connect. The utility will not size this and says the county inspector will approve/disapprove the installation.

The issue is it is a 375' run. Calculating the voltage drop to be below 3% I'm coming up with 3" PVC sch. 40 and 3 - 750 kcmil wires. Does Table 310.16 and a 3% minimum drop apply to primary wires.

Any suggestions would be appreciated.


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#209118 - 03/07/13 06:29 PM Re: Does table 310.16 apply to primary feeds [Re: bwise121]
gfretwell Offline


Registered: 07/20/04
Posts: 9025
Loc: Estero,Fl,usa
I would see if running medium voltage to the shop would be a possibility. If they would hang a transformer outside the shop, problem solved. Otherwise you have some expensive copper to buy.

How far is it from the house? Maybe setting it up as a sub would be better. Is there a real reason why he wants 200a? (covert farming?)
Greg Fretwell

#209120 - 03/07/13 09:11 PM Re: Does table 310.16 apply to primary feeds [Re: bwise121]
Tesla Offline

Registered: 06/16/04
Posts: 1280
Loc: Sacramento, CA
You're in EUSERC territory.

It matters if you're in SMUD, Roseville or PG&E territory.

They have differing standards.

A N Y pipe and wire before the meter m u s t be deeded over to the Poco -- and is, thus, determined by the Poco.

You're being given the run around because you don't have county approved plans in hand.

A f t e r you have them, you'll still have to conform to the Poco (paying fees, too)... it's going to become their property... and their responsibility. I've never seen any of these three Pocos not review commercial Services.

(BTW, really big power users have to provide months, even years, of advance notice to the Poco. Without such co-ordination, the Poco is entirely off the hook WRT timely provision of service. But, that's not you.)

At no time will the Poco lift a finger to help you design the system. As they see it, that's what EEs and C-10s do for a living, and they are not going to favor anyone, particularly a new entrant to the market.


Generally, EUSERC does not favor copper service laterals.

PG&Es Green Book is a 'must have' for any C-10 working in their service area. Roseville has a Blue colored standards book. SMUD = ?.

EUSERC has minimum sizes for service laterals -- and, these days, R E Q U I R E S spare conduit runs on most commercial service laterals.

My last PG&E secondaries were eight (8) five inch (5") PVC schedule forty pipes and elbows. When the conductors were pulled in only two pipes were used. The Poco would not run the other secondary taps until the Service load built up. (!)

My last SMUD secondaries were eight (8) four inch (4") PVC schedule forty pipes and elbows -- with the long horizontal runs in DB120. The secondary pipes were all used -- to feed a single 1600A Service.

I'm assuming in all of this that you've run an actual load calculation -- rather than assuming that the load is 160Amps and steady.

Further, double check to see if three phase power is at the street.

It would cut down on your conductor sizing, no doubt.

#209122 - 03/08/13 05:58 AM Re: Does table 310.16 apply to primary feeds [Re: bwise121]
Scott35 Offline

Broom Pusher and

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
I agree with Tesla; the POCO Representative is Yankin' your Chain (or does not have sufficient experience, to be in the position of Compliance Quoting).

All Utility-Related installs - which in the case for Bwise121's Project will include Secondary Ducts, Secondary Feeder Conductors, and Service Equipment; shall be Compliant to the Specifications and Requirements of the Governing Utility.

The Representative passed on incorrect and false information, in regards to Compliance, and did not mention the Inspections will be performed by the POCO Field Inspection Department - and the DBS needs to Sign-Off the Service Equipment before the Meter Shop may mount the KWH Meter.
DBS (Department of Building & Safety) may request Underground Inspection, in addition to the Utility (POCO).

The Utility _Should Have_ their ESR Manual (Electrical Service Requirements) available On-Line; which may be used to interpret the Specs' that will be presented to you.

You should make arrangements to visit the POCO's Service Design / Engineering Office, to begin the new Service Processes.
The Service Planner assigned to your Project will quote the basic Requirements, Quantities, Materials & Equipment Specifications, Documentation required (Plans, Load calculations, Cut-Sheets, Internal Forms, Permits, Easement Drawings, etc.), along with most important of all: the Fee Schedule! wink.

Tesla mentioned:


Further, double check to see if three phase power is at the street.

It would cut down on your conductor sizing, no doubt.

A request for Three Phase 4 Wire Service would be cool for this Project, as the long Feeder length and Customer Usage (Work Shop) could benefit from a Polyphase System.

Good luck with this Service Request!
Inform us of the progress (or regress...).

--Scott (EE)
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#209123 - 03/08/13 10:00 AM Re: Does table 310.16 apply to primary feeds [Re: bwise121]
gfretwell Offline


Registered: 07/20/04
Posts: 9025
Loc: Estero,Fl,usa
Running it as a sub from the house sounds better all the time. I didn't know about all of that stuff Tesla and Scott were talking about FPL is a lot easier to get along with.

Considering all if the above, bring the house up to 400a and coming off that might be your best bet. He can always sub Meter the shop. These days an old analog meter is dirt cheap.
Greg Fretwell


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