Six disconnect rule

[fandi]

Hello All,
There's a 5 story mixed use building with 50 residential unit with a single line diagram like below.
208/120V 3 phase, 4 W MSA switchboard has 9 disconnects. The 1000A section has a main breaker. The 2000A section does not have a main breaker. Because the 1000A main breaker only shuts off the 1000A section, is this a violation of 230.71?
The 1000A section is for commercial despite the label 'House panels'. There's only one building for this multi-family mixed use building.
My question is:
Which exception of section 230.4 can be used in this case so that 2000A section does not have to have a main breaker?
Thanks.

 

[augie47]

You would meet the "6" disconnect rule in any event { (1)1000 + (4) others).
The 2000 amp could be located remote from the 1000 using the 230.2(C)(1) rule.

 

[fandi]

You would meet the "6" disconnect rule in any event { (1)1000 + (4) others).
The 2000 amp could be located remote from the 1000 using the 230.2(C)(1) rule.

Thanks for your reply. In this case the 1000A and 2000A sections are part of the MSA. If there's fire, firefighters come in looking at the label '1000A' main breaker thinking it's the main breaker of the 3000A switchboard and turned it off but what they didn't know in that crucial and limited time is all the loads on 2000A section are still alive. You're correct but I just want to raise the point about how the 1000A main breaker is labeled. It should be labeled clearly to firefighters so they need to shut off other feeder breakers on the 2000A section also.

 

[augie47]

"Service disconnect 1 of 5.. other 4 to the left"; "Service Disconnect 2 of 5" etc...

 

[david luchini]

I don't think the 1000A section would require a main disconnect either. You could apply the six disconnect rule to each set of service entrance conductors.

 

[electrofelon]

I don't think the 1000A section would require a main disconnect either. You could apply the six disconnect rule to each set of service entrance conductors.

I agree. Look carefully at the wording of 230.71(A)

See 230.2(E) for identification requirements

 

[jap]

The way it's drawn only shows 1 set of 3000 amp service conductors terminating on a common buss.

JAP>

 

[electrofelon]

I don't think the 1000A section would require a main disconnect either. You could apply the six disconnect rule to each set of service entrance conductors.

Hold on David, I agreed. But now I'm taking it back and partially disagreeing after rereading you wording more thoroughly. I agree that the service has 5 service disconnects so it is compliant, however I do not see any allowances to apply the 6 disconnect rule to EACH set of SEC that are installed under 230.40 ex #2. 230.71 does not include #2.

 

[shortcircuit2]

Of note is that in the 2020 NEC those switchboard's would need to be sectionalized for each main as 230.71 no longer allows 6-switches in the same section.

 

[don_resqcapt19]

Hold on David, I agreed. But now I'm taking it back and partially disagreeing after rereading you wording more thoroughly. I agree that the service has 5 service disconnects so it is compliant, however I do not see any allowances to apply the 6 disconnect rule to EACH set of SEC that are installed under 230.40 ex #2. 230.71 does not include #2.

Exception #2 in 230.40 does not have anything to do with the number sets of service entrance conductors that are permitted, so there is no need to list it in 230.71(B).
Exception #1 in 230.40 permits the multiple sets of service entrance conductors for this application, and 230.71(B) permits ech of those sets of service entrance conductors to have up to six disconnects.