Downstream

[hhsting]

I have the following scenarios:

1. I have 1000 amp breaker and downstream panelboard is 800A

2. I have 1200A breaker in switchboard and downstream ATS is 800A

#1 is about panleboard and #2 is about ATs. Would the above be acceptable by NEC 2014? If not then which section(s) is not in compliance?

 

[hhsting]

I have the following scenarios:

1. I have 1000 amp breaker and downstream panelboard is 800A

2. I have 1200A breaker in switchboard and downstream ATS is 800A

#1 is about panleboard and #2 is about ATs. Would the above be acceptable by NEC 2014? If not then which section(s) is not in compliance?

Like to add #1 panelboard is MLO

 

[Hv&Lv]

If this is a test question please tell us what you think the answer is first.

 

[hhsting]

If this is a test question please tell us what you think the answer is first.

Ha! This is whats shown on plans. I gave comments breakers won’t protect downstream equipment. I got response back Breakers are series rated with equipment where is it in NEC 2014. Cannot enforce. Looked but did not find

Please

 

[Hv&Lv]

Ha! This is whats shown on plans. I gave comments breakers won’t protect downstream equipment. I got response back Breakers are series rated with equipment where is it in NEC 2014. Cannot enforce. Looked but did not find

Please

Here’s something on series ratings

Is a series rated panel right for you? | Consulting - Specifying Engineer

Learning objectives: Understand the difference between a "fully rated" and "series rated" electrical panel. Know how to properly choose between the two | Consulting - Specifying Engineer

www.csemag.com

http://web.eaton.com/ecm/idcplg?IdcService=GET_FILE&dID=4796305

 

[hhsting]

Here’s something on series ratings

Is a series rated panel right for you? | Consulting - Specifying Engineer

Learning objectives: Understand the difference between a "fully rated" and "series rated" electrical panel. Know how to properly choose between the two | Consulting - Specifying Engineer

www.csemag.com

http://web.eaton.com/ecm/idcplg?IdcService=GET_FILE&dID=4796305

Ok But the questions post #1 has nothing to do with series rating. Thats response I got from engineer. I know engineer who did plans is confused.

Where is it in NEC 2014 that if upstream breaker is rated at 1000A trip and downstream panelboard bus is 800A MLO then it wont protect the panelboard? Similar question for ATS post #1

 

[augie47]

Do you actually look at the NEC before you ask
#1 408.36 MLO would be a violation.
#2 Depends on the ATS having an internal line breaker .

 

[winnie]

Yea, series rating has nothing to do with it.

A 1000A breaker does not protect an 800A panelboard from overload. However the install may be compliant if other aspects of the system provide the necessary protection.

For example the load breakers in the panel might prevent overload. I don't know the details so can't comment on specifics.

Same with the ATS. The upstream breaker is not protecting the ATS from overload but other aspects of the system may make it a compliant install.

 

[hhsting]

Do you actually look at the NEC before you ask
#1 408.36 MLO would be a violation.
#2 Depends on the ATS having an internal line breaker .

#2 no internal line breaker in ATS

 

[augie47]

#2 no internal line breaker in ATS

Then a violation.
If of no other Article, then 110.3B

 

[texie]

#1 Not compliant. Panelboard must be protected within it's rating. See Art. 408.
#2 Not compliant. ATS must be protected per it's listing. This will be a very specific list of breaker models and sizes.