Series Rating Existing Branch Circuit Breakers

[stuartdmc]

I am consolidating a group old meters for a retail buildings with a new 240v single phase 800 amp meter section with 6 meters and 6 fuse main pull out disconnects, My question is, all six units have different types of panels that have existing branch cir. breakers rated at 10kaic, how am I going to series rate existing the branch circuit breakers rated at 10kaic at the main switchgear?

Stuart

 

[dkidd]

You need to get exact information on the breakers, and then see what the manfacturer has UL listed combinations.

See

http://www.eaton.com/ecm/groups/public/@pub/@electrical/documents/content/1c96944.pdf

for example

 

[jim dungar]

It is extremely unlikely you will find series ratings between different manufacturer's breakers. However you should be able to locate series ratings for fuses (usually class J or T) and breakers, even for panels built back in the mid 80's.

 

[petersonra]

It is extremely unlikely you will find series ratings between different manufacturer's breakers. However you should be able to locate series ratings for fuses (usually class J or T) and breakers, even for panels built back in the mid 80's.

he is not going to be real popular when one of those fuses blows and the store can't reset it.

 

[John120/240]

he is not going to be real popular when one of those fuses blows and the store can't reset it.

Yes that is true. When a fuse does blow or OCPD trip, it would be prudent to

determine the cause of the blown fuse/tripped breaker before resetting. By a

qualified indivual I would say.

 

[jim dungar]

he is not going to be real popular when one of those fuses blows and the store can't reset it.

In general the only time the upstream fuse will open is when there is a bolted fault in the downstream panel. A 'routine' fault on a branch circuit (based on a 200A panel) is extremely unlikely to have a high through fault current.

Regardless, a fault sufficient to clear the main fuse, should be investigated by a qualified individual, rather than being simply reset.

 

[petersonra]

In general the only time the upstream fuse will open is when there is a bolted fault in the downstream panel. A 'routine' fault on a branch circuit (based on a 200A panel) is extremely unlikely to have a high through fault current.

Regardless, a fault sufficient to clear the main fuse, should be investigated by a qualified individual, rather than being simply reset.

In the real world, they will just reset the CB. or worse yet have the stock boy replace the blown fuse.

 

[pete m.]

Another option that you may explore is 240.86(A). Depending on the age of the existing OCPD's an engineer may be able to do a study and provide a solution.

Pete