Disconnect and ground for separate buildings under 1 residential house address/meter

[fandi]

Hello All,
A 600A 240/120V 1 phase 3 wire panel feeds a 200A subpanel 50ft away. Please help me with these two questions. Thanks a lot.

1. Per NEC 225.31, when more than one building or other structure is on the same property and under single management, each building or structure shall be provided with means for disconnecting all ungrounded conductors. Question: Does it have to be a separate disconnect right ahead at the sub panel or a main breaker at the subpanel suffice?
2. The 600A panel has #3/0 ufer and connects to cold water pipe. There is EGC between the two panels. The subpanel 50ft away also has #4 ufer and connects to cold water pipe. I don't know if the cold water pipes are interconnected. Of course we don't want to have two different ground in the system so question: What is the requirement for the grounding at the subpanel?

 

[iwire]

Question: Does it have to be a separate disconnect right ahead at the sub panel or a main breaker at the subpanel suffice?

The main breaker can suffice if it meets the location requirements.

[*]The 600A panel has #3/0 ufer and connects to cold water pipe. There is EGC between the two panels. The subpanel 50ft away also has #4 ufer and connects to cold water pipe. I don't know if the cold water pipes are interconnected. Of course we don't want to have two different ground in the system so question: What is the requirement for the grounding at the subpanel?
[/LIST]

If the subpanel is at separate building or structure you must establish a grounding electrode system at it and connect it the the EGC at the subpanel.

 

[fandi]

The main breaker can suffice if it meets the location requirements.



If the subpanel is at separate building or structure you must establish a grounding electrode system at it and connect it the the EGC at the subpanel.

Thank you so much, Moderator.

 

[GoldDigger]

Thank you so much, Moderator.

Don't thank him because he is a Moderator though. Thank him because he is a really smart and helpful guy.