I've read several archived posts and am still not too clear on these articles. I'm on a job now for a retirement condo unit, no health care. The exit and emergency lighting is all coming from several emergency panels(no battery lights) which will be powered by a 300kw genset. There are two feeders coming in and power the egress lighting, exits, as well as the elevator,sump pumps, phone panel,security and fire panels and one recepticle and one light in each living unit. All of the branch circuits are run seperate from any normal power stuff. The question is by code can these feeders from the genset power both the emergency lighting and the other items?
Art. 700 and 701 wiring
- Thread starter patc
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- Massachusetts
Re: Art. 700 and 701 wiring
It sounds to me like article 700 (Emergency) and article 702 (Optional Standby Systems.)
Anything that is truly article 700 emergency must be kept entirely separate from all other building wiring.
The items that fall under article 702 Optional Standby Systems can be intermixed with the 'normal' power and any article 701 systems.
It is possible to do this from one generator, the generator would need to have two circuit breakers directly connected to the generator windings. One breaker would feed the article 700 items the other breaker would feed any other items.
Once you leave these separate breakers the systems can never intermix again, this means separate transfer switches and distribution panels.
It sounds to me like article 700 (Emergency) and article 702 (Optional Standby Systems.)
Anything that is truly article 700 emergency must be kept entirely separate from all other building wiring.
The items that fall under article 702 Optional Standby Systems can be intermixed with the 'normal' power and any article 701 systems.
It is possible to do this from one generator, the generator would need to have two circuit breakers directly connected to the generator windings. One breaker would feed the article 700 items the other breaker would feed any other items.
Once you leave these separate breakers the systems can never intermix again, this means separate transfer switches and distribution panels.
Re: Art. 700 and 701 wiring
I guess part of my confusion here is that I can't get a good read on what each system can have on it. In reading the FPN for art. and 701 they basically appear very similar. They can both have similar equipment connected to them. How do you determine if the installation falls under 700 or 701? There are two xfer switces called for in this installation. Which brings up another question. They are not located in the same room. Do they have to be grouped?
I guess part of my confusion here is that I can't get a good read on what each system can have on it. In reading the FPN for art. and 701 they basically appear very similar. They can both have similar equipment connected to them. How do you determine if the installation falls under 700 or 701? There are two xfer switces called for in this installation. Which brings up another question. They are not located in the same room. Do they have to be grouped?
- Location
- Massachusetts
Re: Art. 700 and 701 wiring
You mentioned;
Sump pumps, security systems, receptacles in units would not be 'emergency', I would expect to see those loads treated as optional standby.
The one light in each unit could be part of the emergency system if it is part of the required egress lighting or it could simple be optional.
The transfer switches do not have to be grouped and a good design puts the emergency transfer switch and distribution in it's own fire rated electric room, away from the other electrical systems.
The idea is not to let someones optional malfunctioning hot plate from opening any overcurrent devices supplying 'emergency' loads.
Article 700 has the most stringent requirements and what is allowed / required to be on the emergency system is determined by the AHJ.
You mentioned;
In the area I work the egress & exit lighting along with the fire alarm would definitely be on the emergency system, the elevator could go either way.
Sump pumps, security systems, receptacles in units would not be 'emergency', I would expect to see those loads treated as optional standby.
The one light in each unit could be part of the emergency system if it is part of the required egress lighting or it could simple be optional.
The transfer switches do not have to be grouped and a good design puts the emergency transfer switch and distribution in it's own fire rated electric room, away from the other electrical systems.
The idea is not to let someones optional malfunctioning hot plate from opening any overcurrent devices supplying 'emergency' loads.
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