NEC Requirement for Service Entrance Disconnects

[wbdvt]

A building I am working on an study for has 3 transformers (500kVA, 208/120V secondary) and each transformer feeds a separate switchboard. Only one switchboard has a disconnect switch (Pringle with KRP-C-1600A fuses) while the other two switchboards are directly connected with no disconnect means from the transformers. I know that this is a violation of Article 230.70 in the 2020 edition but I am curious if anyone knows how far back this requirement goes. This facility was built in 1983.

Thanks in advance for all replies.

 

[infinity]

Prior editions of the NEC allowed up to 6 service disconnects so it is possible that you switchboards without a single main are code compliant.

 

[wbdvt]

Infinity, thank you but I should have pointed out that the other two switchboards contain the following fused switches:
Switchboard 2 has 6 fused switches feeding loads
Switchboard 3 has 8 fused switches feeding loads

So in order to turn off all loads, a total of 15 switches would have to be operated.

 

[Tulsa Electrician]

Does switch board three have a main.
Is there a switch board, one

 

[wbdvt]

Switchboard 1 has a main disconnect switch the others do not

 

[jim dungar]

Are these customer owned transformers or do they belong to a utility?
Back in 1983 equipment on the secondary of customer owned transformers were not always treated like service entrance equipment. For supervised industrial locations it was possible to have more than 6 disconnects.

 

[wbdvt]

Hi Jim, these are utility owned transformers. This is also in a building that houses condos, health spa/pool, restaurant and commercial store.

 

[augie47]

I see no justification in #3 having 8 disconnects
As infinity notes (in post #2), #2 might be compliant.
With total capacity over 2,000 amps, multiple services are allowed and each would allow the 6 disconnects.
So, IMO, only #2 has a violation..

 

[infinity]

I see no justification in #3 having 8 disconnects
As infinity notes (in post #2), #2 might be compliant.
With total capacity over 2,000 amps, multiple services are allowed and each would allow the 6 disconnects.
So, IMO, only #2 has a violation..

And if those two extra disconnects meet the exceptions to the 6 switch rule it still may be code complaint.

 

[Tulsa Electrician]

Edit, did not see previous post on exception.
Another item to consider are all eight In use. I have ran across where they added a second switch board and moved load leaving illegal handle in place due to buss tap.
They just gutted the inside.

 

[RWC/NC.]

Edit, did not see previous post on exception.
Another item to consider are all eight In use. I have ran across where they added a second switch board and moved load leaving illegal handle in place due to buss tap.
They just gutted the inside.

Well, unfortunately. sometimes those things happen (where needing edit due to misprints) or denoted exceptions... We're all just human..

 

[wbdvt]

Thank you all for your responses. I visited the facility yesterday to verify all information I was provided and am convinced it is code compliant as noted below:

SWBD 1 - supplied by dedicated transformer and has a main disconnect switch. So no issue there.

SWBD 2 - supplied by a dedicated transformer and has a total of 5 fused disconnect switches feeding loads. No issue there.

SWBD 3 - supplied by a dedicated transformer and has a total of 6 fused disconnect switches feeding loads. No issue there.

So, all is code compliant.

 

[Tulsa Electrician]

Well that's great news.
Thank you for letting us know.
That has to make you feel better.

 

[infinity]

Thank you all for your responses. I visited the facility yesterday to verify all information I was provided and am convinced it is code compliant as noted below:

SWBD 1 - supplied by dedicated transformer and has a main disconnect switch. So no issue there.

SWBD 2 - supplied by a dedicated transformer and has a total of 5 fused disconnect switches feeding loads. No issue there.

SWBD 3 - supplied by a dedicated transformer and has a total of 6 fused disconnect switches feeding loads. No issue there.

So, all is code compliant.

Thanks for the follow up.

 

[wbdvt]

ok, perhaps I am mis-reading the code but not sure as the switchboard has 2 disconnects in each vertical section. This would appear not to meet 230.71(B)(3) but then Informational Note No. 2 seems to say it is ok??
I am attaching a pic.

 

[jim dungar]

ok, perhaps I am mis-reading the code but not sure as the switchboard has 2 disconnects in each vertical section. This would appear not to meet 230.71(B)(3) but then Informational Note No. 2 seems to say it is ok??
I am attaching a pic.

You need to look at the NEC from the original install back in 1983.
The requirement for 1switch per vertical section is a recent addition.

 

[wbdvt]

Thanks, anyone have this edition handy which would be the 1981 edition?

 

[infinity]

ok, perhaps I am mis-reading the code but not sure as the switchboard has 2 disconnects in each vertical section. This would appear not to meet 230.71(B)(3) but then Informational Note No. 2 seems to say it is ok??
I am attaching a pic.

Which code cycle are you referring to?

 

[wbdvt]

The above is in the 2020 code book but the facility was built in 1983 so I think the 1981 edition would be the code it was built to. I just ordered that code book from Amazon.
The oldest code book I now have is from 2008 and it does not contain the requirement on vertical sections so this is a recent addition. I believe this installation is compliant since it was compliant when built.