Neutral/Ground service conductor sizing

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sparky_pdx

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Hi,
1st time poster. I'm a journeyman electrician in Portland. Mostly do residential, but have a commercial question. New 200A service, meterbase
& mast @ front of building, 60' pipe outside wall, LB directly to panel inside.
Power company wants a metermain instead of meterbase. Already have 3 wire service conductor, 4/0, 4/0, 2/0 Al. Per tables in 250, I'm pretty sure I can just add a #4 Cu Ground into pipe & seperate Neutral & Ground bus in Panel. Just wanna be sure. I noticed that 4w, 200A SER cable has 4/0, 4/0, 4/0, 2/0 Al. 1 other quick question, bonding of gas & water pipe can happen anywhere, not just 5' from entrance.
Thanks in advance.
Sparky
 
The NEC would not require the external main disconnect, but if the POCO does, it does.

Yes, you could use SER between the combo and the interior panel; as long as the neutral is insulated beyond the main disconnect, as Pierre mentioned.

The water pipe can be bonded anywhere. Using it as an electrode requires the 5-ft limit.

Gas, I'm not sure. Typically, the EGC of the circuit "likely to energize" the pipe is adequate bonding.
 
The 2/0 AL neutral I already have is insulated with a yellow stripe.
We're driving 2 ground rods for Ground Electrode & #4 for the GEC,
as well as #4 Cu for the bonding of gas & water.
Thanks for your help, I really appreciate it...
 
I'm confused you have an existing (new) 200A meterbase installed and they're making you swap it out? What's their reasoning? Are they supplying the meter-main? They didn't even give you the option of adding an outdoor disconnect?

When you say 60' pipe... I assume 60' RMC mast why use SER? Is it even allowed in conduit? (Sorry 25 years running pipe have never used SER... only even seen it a few times)
 
"Mostly do residential, but have a commercial question. New 200A service, . . . Power company wants a metermain instead of meterbase. Already have 3 wire service conductor, 4/0, 4/0, 2/0 Al."

My reading of 310.15(B)(6) and Table 310.15(B)(6) is that 4/0 Al is allowed for 200 Amp ungrounded conductors in dwelling services only.

I suppose it might be possible to use a 200 Amp breaker for 4/0 Al under provisions of 240.6.
 
Bob NH said:
I suppose it might be possible to use a 200 Amp breaker for 4/0 Al under provisions of 240.6.
Click to expand...

As long as his calculated load is under 180 amps he can use 240.4(B) and 240.6 to install a 200 amp service with 4/0 AL.
 
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