Battery Pack Wiring

horsegoer

Senior Member
Curious how you guys wire this. So EM battery pack needs separate hot leg for charging the battery. Does this mean if your running 12/2 MC only you actually run a 12/3? You'd have to land the extra hot leg on another breaker in the panel. That doesn't make sense but where would the power come from for the extra hot leg needed for charging the Em pack?

david luchini

Moderator
Staff member
Curious how you guys wire this. So EM battery pack needs separate hot leg for charging the battery. Does this mean if your running 12/2 MC only you actually run a 12/3? You'd have to land the extra hot leg on another breaker in the panel. That doesn't make sense but where would the power come from for the extra hot leg needed for charging the Em pack?
Why would it need a "separate" hot leg for charging the battery?

horsegoer

Senior Member
Why would it need a "separate" hot leg for charging the battery?
Engineer mentioned you have to run 12/3 in lieu of 12/2 when you have an EM battery pack in fixture. WOuld think you could just tap the ONE hot leg and run the battery pack.

david luchini

Moderator
Staff member
Engineer mentioned you have to run 12/3 in lieu of 12/2 when you have an EM battery pack in fixture. WOuld think you could just tap the ONE hot leg and run the battery pack.
Hot, neutral, switched. Seems like 3 conductors to me. Unless you just want the light to be on all the time.

horsegoer

Senior Member
Hot, neutral, switched. Seems like 3 conductors to me. Unless you just want the light to be on all the time.
Well I don't follow exactly. So lets make it simple. One switch 1P toggle switch( never exists nowadays with the lighting controls) controlling 2- 2x2 lights. Now two ways to do this, bring the circuit to a box in ceiling then feed down to light switch or bring fed to switch. Most common is bringing power and then switch leg/power up to lights. Wouldn't that just 12/2 to switch and 12/2 up to lights?

david luchini

Moderator
Staff member
Well I don't follow exactly. So lets make it simple. One switch 1P toggle switch( never exists nowadays with the lighting controls) controlling 2- 2x2 lights. Now two ways to do this, bring the circuit to a box in ceiling then feed down to light switch or bring fed to switch. Most common is bringing power and then switch leg/power up to lights. Wouldn't that just 12/2 to switch and 12/2 up to lights?
I don't follow. Is your "most common" way bring the circuit to the switch first or the to ceiling fixture first?

horsegoer

Senior Member
I don't follow. Is your "most common" way bring the circuit to the switch first or the to ceiling fixture first?
Sorry. To switch first.

david luchini

Moderator
Staff member
Sorry. To switch first.
So then, 12/2 to switch and 12/3 to lights. Hot, Neutral, Switched, like I mentioned before.

horsegoer

Senior Member
Normally just 12/2 from switch to light fixture. Your saying 12/3 because of the EM pack?

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david luchini

Moderator
Staff member
Yes, 12/3 because of the EM pack. Otherwise the EM pack would be pretty much useless.

Dsg319

Senior Member
Just need to tie the hot conductor for the em pack into the line side of the switch so it is constantly energized. Otherwise you will only be charging the battery while the light is on.

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qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Feed the emergency light from the same unswitched hot that is feeding the lights in the room.

LarryFine

Master Electrician Electric Contractor Richmond VA
You need an unswitched hot so the light knows the difference between a power outage and normal light switching.

Thanks guys!!!!