Emergency Systems 700.10 intent?

[Poelect]

"Wiring from an emergency source shall be kept entirely independent of all other wiring "
What is the intent of this?
How do you deal with it in a remodel were it was all run in the same raceway?

 

[roger]

"Wiring from an emergency source shall be kept entirely independent of all other wiring "
What is the intent of this?

It means what it says, it must be separated from all other wiring.

How do you deal with it in a remodel were it was all run in the same raceway?

If the remodel is to be brought up to current code you would have to supply raceways, boxes, barriers, etc... as needed.

Are you sure this is emergency wiring verses Legally Required or Optional Standby?

Roger

 

[charlie b]

The intent is to prevent a short circuit or other condition of damage to the non-emergency wiring from causing damage to the emergency wiring.

 

[qcroanoke]

Are you sure this is emergency wiring verses Legally Required or Optional Standby?

Roger

+1.
Emergency systems are one thing
Legally Required and optional standby is a whole nuther ballgame.

 

[Poelect]

7oo.1 and 700.2 seem to make it clear that my Legally required egress lighting makes it an Emergency System.
Building upgrade and want to place every other fixture on a generator.

 

[iwire]

Building upgrade and want to place every other fixture on a generator.

Then you are back to optional standby.

You cannot add as many light fixtures as you want to an emergency system.

 

[Poelect]

You cannot add as many light fixtures as you want to an emergency system.

Why is that? If I cant share the raceway, just put them all on the standby system.

 

[steve66]

Why is that? If I cant share the raceway, just put them all on the standby system.

Only lights specifically required for emergency egress lighting are allowed on the emergency system. Minimizing the number of lights on the emergency system minimizes the possibility that one light develops a problem that could take out the entire circuit. (For example, one light could develop a shorted ballast, and that could trip the branch breaker taking out the entire circuit.) So someone (usually an engineer) has to design the emergency lighting system and decide which lights are required.

Also, the code requires two separate lighting systems - a normal system and an emergency system. So that also prevents you from just putting all the lights on the emergency system.