Transfer Switch and Existing 3 Wire Feed

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eds

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Existing set up from the early 90's had the meter on the residence, fed underground from overhead service drop approx 150' with the last 10' or so under concrete most likely URD. POCO needed to reroute the service drop, they moved the meter from the house to the overhead service drop pole, meter has a self contained 200 amp breaker, so thus it is the service disconnecting means. Existing 3 wire setup was left in place (allowed in earlier versions of the NEC) now at automatic transfer switch and generator are in the works. Appropriate to leave the 3 wire feed without a e.g.c to the residence. Based on the 2005 NEC
 
If I'm not mistaken, a switch would allow the 3 wires to be considered service conductors, but an OCPD makes them a feeder.
 
The idea of not using a service entrance rated transfer switch (no ocpd) and the exception 250.32 (B) (1) exception 1 make this code compliant? Or does the fact that I am adding the transfer switch, require me to update the 3 wire feed to 4 wire?
 
I would think that in the context of 250.32(B)(1) Exception 1, a service entrance rated transfer switch would be the proper type to use.

Cheers, Wayne
 
wwhitney said:
I would think that in the context of 250.32(B)(1) Exception 1, a service entrance rated transfer switch would be the proper type to use.

Cheers, Wayne
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Even if it has a meter main in front of it. Meter main has a 200 amp ocpd
 
eds said:
Even if it has a meter main in front of it. Meter main has a 200 amp ocpd
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Sure, but the feeder is ungrounded, and electrically it's identical to a service (other than having OCPD). So the same issues of using the neutral for bonding, connecting a GES, and originating the EGC system apply, just like a service.

Cheers, Wayne
 
I think the detailed resolution depends on whether POCO considers that by making that change they moved the service point from its original location to a new one. The 200 breaker at the pole is not reasonably located to be the main disconnect of the building, but it may still qualify as the service disconnect.
The question of whether the existing 3 wire service conductors, now feeder conductors, can continue to be grandfathered in even when the ATS and generator are added is yet a third question.
 
I don't see why the applicability of 250.32(B)(1) Exception 1 would be affected by adding an ATS and a generator.

Cheers, Wayne
 
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