As I read art. 700.9,I think it says that I can't run a feeder from a generator in the same conduit as the feeder from a 400a out side disco to a 400a distribution panel.The generator will power some emergency lighting,receps and exit lights. Am I correct? Thanks for any help, Russell

russ you are right you cant run generators lines with ulites line due saftey and if i recall it there is other section in nec codes too and transfer switch set up. i hate to agure with you but it will be wise idea to put a seperate panelboard for delcated lines. i see some installements at few places have seprate panelboards one for normal line and the second one for geneator set up with transfer switch

i am sure there are few spots in nec say about it sec 700 and sec 450 if i rember it right deal with it maybe i am wrong but check few spots in there

merci marc

Russell

You are correct the only places that Article 700"Emergency Power" and "Normal Power" can occupy the same enclosure is when it has to, like at the transfer switch, or a light fixture that uses both sources of power, the EEs often split feed drop in fixture so only half is from generator.

Another spot we might have the two systems in the same enclosure is for relays that override wall switches for emergency lighting, if you put required emergency lighting on a wall switch you must provide automatic override during a power failure. 700.17

As far as raceways I can not think of anytime mixing the systems would be allowed.

Bob

I just noticed you mentioned receptacles, be careful with this as you can not have convenience outlets connected to Article 700 systems, they would need a second transfer switch fed from a second breaker on the generator or a separate generator, and then separate panels and circuits.

It gets costly very fast for just some outlets.

Read the scope of 700, 701 and 702 and you can get a feel for what can be on each system.

We build a lot of stores for a super market chain, we typical install one large generator that will run 700,701,702 loads if the large one drops out a small one picks up just the 700 loads.


[This message has been edited by iwire (edited 03-15-2003).]

This is a situation that came up yesterday at a small strip mall. The building owner wants to install a genset that will supply a 100a panel for 1/2 of some layins such as iwire describes,and a few exit lights and receps also. I just wanted to make sure I was on the right track before it got too far along. Thanks Marc and Bob. Russell

It sounds like this is not a 700 or 701 installation. It appears to be covered by 702 only. Look closely at the scope statements of these articles.
Don

The first post says "emergency lighting" and "Exit signs" here there would be no debate that article 700 would apply.

Unless the owner is adding on his own initiative this in addition to existing emergency lighting.

I should have been clearer in my posts.The generator powered ckts are to consist of some 4 bulb 2x4 lay-ins wit 2 bulbs each to be gen. powered. This is in addition to the legally required emergency lighting already in place.Today I talked him into changing the exit lites he wants to add from the gen. to adding them onto an existing exit lite ckt. Now as for the receps in question, these are to be wired to the gen. served panel. These ckts. will serve as backup power for some chest and upright freezers and refrigerators in a resturant in the bldg. These are residental type freezers and refrigerators and a couple of upright coolers. I also discovered today that he doesn't want the expense of an automatic transfer switch. Should I just provide additional receps at the freezer locations powered by the gen. panel? Can I still power 1/2 of the layins from the genset? These new developments would change the installation from an optional standby system to a seperately derived system and would all have to be piped seperately from existing systems? Sorry guys but the playing field seems to keep changing. Thanks for your help. Russell

I think you are on the right track keeping the exit lights on the existing emergency circuit. Anything that is part of the life safety system needs to be kept separate to what you are proposing. If you do this you can classify the new system as an optional stand by system and wire it per article 702. Separately derived and optional stand by are not part of the same discussion here. Whether it is separately derived or not has to do with grounding and bonding, not emergency or optional.

That being the case it sounds like article 702 optional standby, so wiring can be mixed with other systems 702.9.

As I understand it you are free to power anything you want from this system as long as your "emergency loads" are already taken care of.

Reliance makes a 100 and a 200 amp panel with 2 mains Like 100 amp normal main and a 60 amp generator main, these are mechanically interlocked so only one can be on at a time, this will save buying a separate manual transfer switch.

Thanks all, When I get the setup all figured I'll post back for a critique. There's no ahj and I want this to be code compliant. Thanks again. Russell