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!
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!
#22530 - 02/23/0308:56 PMRe: exit sign and emergency light hookup?
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.
#22531 - 02/23/0309:03 PMRe: exit sign and emergency light hookup?
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
Bob Badger Construction & Maintenance Electrician Massachusetts
#22532 - 02/23/0309:09 PMRe: exit sign and emergency light hookup?
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.
#22534 - 02/24/0309:35 PMRe: exit sign and emergency light hookup?