I'm an apprentice and I have a question. I am used to installing exit sign/emergency light combos. This time I must install an exit sign and an emergency lighting unit seperately. Everything will be surface mounted using emt. I will be running emt from the panel to the box for the exit sign and then to a box to a receptacle next to the lighting unit for it to be plugged into with a cord.The 120VAC circuit will supply both of these devices an no others.There will be no other wires in the conduit. My question is how do I supply the back-up power(6VDC) from the emergency light unit to the exit sign? I want it to look nice. I don't think that I can run 6VDC in the same conduit as the 120VAC.Is the exit sign considered a remote device of the lighting unit in this case? If it is can I run 6VDC in the same conduit as the 120VAC if all conductors are insulated to the highest voltage in the conduit? If not does anyone have any suggestions on how to wire it so it looks nice? Thanks!

Hi RobbieD,
Welcome to the board.

Typically, the units that I have worked with are not designed to be cord and plug connected.

Your exit sign needs to have the circuitry for 6VDC which means it would already have it's own battery.

Does this help?
Dave



[This message has been edited by WebSparky (edited 02-23-2003).]

these lights usually always have their own battery back-up, chargings system, and a.c. to d.c. conversion circuitry already inside. all you have to do is supply the a.c.


gramps

RobbieD-Might want to check local fire code. In RI, emgergency lighting is required to be connect to the lighting circuit.

The exit sign is an individual unit. It has 3 lamps inside, the 2 outer ones are to be connected to 120VAC. The middle lamp is to be connected to 6VDC. The unit does not have a battery or any asssociated circuitry.In the event that the 120VAC power goes out the middle lamp will light up because it must recieve its back-up power (6VDC) from the emergency light units battery. The emergency light unit is to be located about 10 feet from the exit sign. It is a unit with 2 lamps mounted on the outside of its case. It has a cord which is plugged into a 120VAC receptacle. When the power (120V) goes out the emergency light unit has a relay inside which releases and supplies 6VDC from its battery to its lamps mounted on its caes. Inside the unit there are output contacts, these can be used for remote heads or for an exit sign. I want to wire the unit to the exit sign and was looking for a good method. Just writing to clarify the question.
Looking for suggestions. Thanks!

Hey Robbie,

Welcome to the board. Here in NJ the NEC requires the emergency lights to be on the same circuit as the normal lighting. The same as in RI, as Arthur said. Check 700-12 of the NEC. Too many times I have seen contractors forget this fact.

Run seprate conduits for the DC output, not because of the voltage difference but because the AC is "Normal" power and the DC output is "Emergency" power article 700 codes apply 2002 NEC 700.9(B). This can look strange having two conduits going between the same two JBs (there are exceptions for the JBs)I had to go back to a job because somebody "cheated" a little on this and I had to fix it.

I do not know your local codes but in MA cord and plug connected EBUs are not allowed
Bob

2002 NEC 700.12(E)

"The branch circuit feeding the unit equipment shall be the same branch circuit as that serving the normal lighting in the area and connected ahead of any local switches. ..."

But when you look at the exception for 700.12(E) (more then 3 lighting circuits in a common space, EBUs can be separate circuit)

This is common in stores, office space for cubicles, warehouses etc, watch out for local codes though.

Bob

Sounds like you're Canadian here but I may be wrong, Its pretty common here to have one main battery pack supplying a whole hallway or small building here. What you have to check is the wattage output of the battery pack and the wattages of the exit sign and heads, most 6v heads are 9 watts and an exit is close to the same per bulb. I've heard it argued both ways on the DC and AC being run in the same conduit, the reason being the AC and DC arent energized at the same time because the DC is only on when the AC is diconnected. I personally wouldnt do it and would run the 2 separate conduits. The cord is a pretty common thing for us too, We usually disconnect it off the card on the inside(be careful of your warranty though.)this stops people from unplugging them if they are in a common area. Also if you find that the wattage of your battery pack isn't enough look into getting a led bulb for your DC light in your exit it will bring down your wattage quite a bit. Hope this helps.

Don't have the bible in front of me so I am not sure if this is allowable, but what about a wiremold (or similar) raceway with partition?

I have used this method a number of times to supply 120 and various low voltage cables to office spaces and the like.

The same idea as a power pole to supply power and voice/data to something that's not close to a wall.

[This message has been edited by Elec_VA (edited 02-24-2003).]

Robbie:
Please read 700-16....you cannot use s exit fixture with only one bulb.
Your boss would be better off getting a self contained unit....quick and effective, and NEC compliant.
John

In Ontario(If that is where your installation is) you cannot run DC & AC in same raceway.

CSA rule 46-108 (3) "Say's no WAY"

and as iwire noted NEC 700-9 (B),(1),(2),(3),(4)
Basically say's Junction Box attached to fixture (key word "attached),in fixture, and in your case Battery pack.