given: 2 separate buildings , by use of a firewall, each building as its own service. ( common area branch circuits suppiled from one of the services is used to supply secuity lighting for both buildings) Should the electrodes from each service be bonded together to stablize any difference in potential ? What code section requires the electrode to be bonded in this case ?

Nothing requires them to be bonded together if they are truly separate in separate buildings. This is not the case though, there are common area circuits serving both buildings from one of the services. Also, are there two separate water services from the street (or one that splits?) and do they require bonding? Are the meters and any disconnects next to each other?

-Hal

210.25 prohibits branch circuits from one dwelling to supply common area lighting.

IMO...you will need a third meter for common area lighting.

I would just wire the lighting for the each side of the buildings area from that sides service.

shortcircuit

the services are located on each builing,about 200 feet apart, this is a multifamily structure with a firewal. My concerns were because both building security lights are supplied from one owner's panel, the electrodes from both buildings should be bonded ?

If this is a multi-family building why didn't you provide for a house panel? I hope the owner of the panel feeding the security lights never gets mad at his neighbors!!

210.25 prohibits branch circuits from one dwelling to supply common area lighting.

Yup, I missed that one. Shows how much multifamily I do.

I assumed that the owner would occupy the unit with the lights on his meter. Even if this were allowed what happens if the unit gets sold?

I agree with the others- either split the lighting up and put it on the respective meters or provide a house meter. I think which way to go would depend on the layout and where the lighting is located. I don't think any unit should be paying for site lighting.

-Hal

A little off the actual question, I guess, but I'm confused about the actual building. Is this one(1) building or two(2)? If they are physically attached in any way above ground they are a single building. Why are there 2 services? Or am I reading this wrong?

Sorry, brain fade I guess. I see the situation now. But still, you can't feed house lighting from one service if it penetrates the other living space. That's what the firewall is there for to begin with.

[This message has been edited by Gregtaylor (edited 03-07-2005).]