bill@usps06492
Member
- Location
- Connecticut
I just finished installing a 480v 3ph 250a feed into a new peice of equipment, along with a fire alarm cable for a shunt trip relay, that will shut the machine down if the fire alarm goes off.
The installer of the machine told me to route the fire alarm cables through the same raceway as the 480(the relay is next to the main disconnect). I told him that that?was a violation of the NEC,and even showed him Art 760.55(A). He said that this is the standard installation for this equipment.Art760.55(D) allows power limited wiring in the same enclosure, but it doesn't mention raceway.Since the f.a. cables do not have any voltage on them until the alarm goes off, would that make a difference? It is my understanding that the reason the two systems are not in the same raceway, unless there is a barrier, is because the higher voltage could be induced or transposed onto the l.v. cable causing all kinds of havoc and safety issues.
Bill
The installer of the machine told me to route the fire alarm cables through the same raceway as the 480(the relay is next to the main disconnect). I told him that that?was a violation of the NEC,and even showed him Art 760.55(A). He said that this is the standard installation for this equipment.Art760.55(D) allows power limited wiring in the same enclosure, but it doesn't mention raceway.Since the f.a. cables do not have any voltage on them until the alarm goes off, would that make a difference? It is my understanding that the reason the two systems are not in the same raceway, unless there is a barrier, is because the higher voltage could be induced or transposed onto the l.v. cable causing all kinds of havoc and safety issues.
Bill