PrecisionMechanical wrote:
wrote in message
oups.com...

A good friend has a FPE 100 amp cabinet. Obviously the breakers are
JUNK! He lacks the $ for a new service right now. He wonders if he
could replace the 100 FBE cabinet with a 200 amp new service but
install for now a 100 amp main breaker till he has the bucks to replace
the service completely.

Anything unsafe about this rather creative idea?



The mains breaker only protects the buss that it's being tasked with
feeding....and so it follows that it's utility as to providing overcurrent
protection has absolutely nothing to do with the ampacity of the circuit
that it's being fed from.

IOW, your overcurrent protection likely resides at the primary transformer
connection.....

Kapish ???

--

SVL


The Over Load Protection for your service entry conductors is your main
breaker or fuses. The only fault protection for your service
drop/lateral and service entry conductors is the supply fuse for the
transformer. Given that it is sized to the entire ampacity of the
transformer a lot of damage will occur before it opens. That is why it
is so important that the load calculation be carefully done and the main
Over Current Protective Device be properly sized. If the Service
conductors are properly sized the likelihood of an overload, that will
lead to insulation breakdown, and a fault condition developing, is very
small.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison