Utility wiring 200A Service

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jap said:
I'd think we'd actually need to look into 551 and 310.15(b)7 is actually for dwelling units which in my book an RV is not.
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Good point, Op said RV with 50A power outlet, not Mobile Home. So 550.33(B) does not apply here.

It appears §551.42(D) describes the Op's "50-ampere-rated panelboard." Or 50A outlet §551.72(C)
"50 amperes shall be supplied from a branch circuit of the voltage class and rating of the receptacle."

So a 200A service can feed 50A disconnects with #6cu @ 60ºC, or 75°C rated outlets with #8cu, rather than 3/0 copper.
 
Table 551.73(A) Demand Factors may allow PoCo to feed RV's with smaller service conductors.

If I'm reading correctly, for 36+ RV's, 41% demand for service entrance conductors.
 
ramsy said:
Good point, Op said RV with 50A power outlet, not Mobile Home. So 550.33(B) does not apply here.

It appears §551.42(D) describes the Op's "50-ampere-rated panelboard." Or 50A outlet §551.72(C)
"50 amperes shall be supplied from a branch circuit of the voltage class and rating of the receptacle."

So a 200A service can feed 50A disconnects with #6cu @ 60ºC, or 75°C rated outlets with #8cu, rather than 3/0 copper.
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A 200a service can feed a lot more than just that, but, if they decide to put in a 2p 50 amp branch breaker to feed a 50 amp rv outlet and plan on using rhw, thhw,thw,thwn,xhhw,use or zq as the conductor of choice in a raceway,cable or earth, then they can use #8 copper at 75d C with a #10 copper EGC per table 250.122.

JAP>
 
ramsy said:
Good point, Op said RV with 50A power outlet, not Mobile Home. So 550.33(B) does not apply here.

It appears §551.42(D) describes the Op's "50-ampere-rated panelboard." Or 50A outlet §551.72(C)
"50 amperes shall be supplied from a branch circuit of the voltage class and rating of the receptacle."

So a 200A service can feed 50A disconnects with #6cu @ 60ºC, or 75°C rated outlets with #8cu, rather than 3/0 copper.
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200 amp meter socket can have less then 200 amp conductor connected to it.

If there is a single 200 amp main breaker for a service disconnecting means - it must be supplied with 200 amp conductor even if the load calculation is only 40 amps. If the service lateral/service drop conductors are POCO owned/maintained conductors - NEC doesn't apply to them and they can very well run 4 AWG if they want to even though the main breaker is 200 amp, beyond the load side of the "service point" they would need to be 200 amp conductors in that situation.
 
kwired said:
..If there is a single 200 amp main breaker for a service disconnecting means - it must be supplied with 200 amp conductor..
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Yes, wire shall not become the fuse.

Service disconnect may be < meter socket.

The 200A meter's service disconnect may be 2-pole 50A, to feed 75°C rated #8's to 75°C rated NEMA 14-50 Receptacle, with #10 EGC per JAP.
 
ramsy said:
Yes, wire shall not become the fuse.

Service disconnect may be < meter socket.

The 200A meter's service disconnect may be 2-pole 50A, to feed 75°C rated #8's to 75°C rated NEMA 14-50 Receptacle, with #10 EGC per JAP.
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Well that's not exactly what JAP said. :) but it could be.

If you wanted to apply the 6 movement rule and not put a single 200 amp disconnect in the panel, the 2p 50 could certainly count as one of the movements and be perfectly legal.

JAP>
 
Only the POCO can not allow you to land a GEC(s) in a meter can. Inspector can advise you not to so POCO will connect, but it is not his place to disallow because it is Code compliant (unless there is a locally adopted amendment).
 
Twoskinsoneman said:
Well he SAYS it violates 250.24(A)(1) because the absolutely inviolate meter tamper tag makes the idea of accessibility utterly absurd. (paraphrased :D)
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How are service disconnects changed if absolutely inaccessible.

Locked, or not accessible to unqualified persons, does not exclude qualified persons servicing equipment. 250.68(C) Exception
 
ramsy said:
How are service disconnects changed if absolutely inaccessible.

Locked, or not accessible to unqualified persons, does not exclude qualified persons servicing equipment. 250.68(C) Exception
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To change or service a service disconnecting means you are supposed to de-energize the service conductors, which the POCO must do... and they'll make the meter can accessible. Any method other than this or by explicit permission to cut the seal is considered unauthorized tampering by most POCO's under non-extenuating circumstances.

You need to read and compare the Article 100 definitions of accessible and readily accessible.
 
After unsealed by PoCo, meter equipment may be -

Accessible (as applied to equipment). Admitting close
approach; not guarded by locked doors, elevation, or other
effective means.

And should always be -

Accessible (as applied to wiring methods). Capable of being
removed or exposed without damaging the building structure
or finish or not permanently closed in by the structure or finish
of the building.
 
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ramsy said:
After unsealed by PoCo, meter equipment may be -

Accessible (as applied to equipment). Admitting close
approach; not guarded by locked doors, elevation, or other
effective means.

And should always be -

Accessible (as applied to wiring methods). Capable of being
removed or exposed without damaging the building structure
or finish or not permanently closed in by the structure or finish
of the building.
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It is both even when it is sealed.
 
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