Exit sign and wall mounted emergency backup

[hhsting]

I have exit sign self battery type and wall mounted battery pack.

Both of these are powered from local branch circuit which also power normal light and are on load side of local switch.

Should not the exit and wall mounted battery pack be on separate dedicated circuit then normal and ahead of local light switch?

 

[LarryFine]

They should be on the local lighting circuit, ahead of the local switch.

 

[don_resqcapt19]

Unit equipment should never be permitted on a separate circuit as that would permit a case where the normal lighting circuit fails and the EM lights do not come on.
However CMP-13 does not seem to understand that as a 2020 change actually permits the unit equipment to be on a separate circuit, even if there is only a single lighting circuit for the area.

 

[gadfly56]

Unit equipment should never be permitted on a separate circuit as that would permit a case where the normal lighting circuit fails and the EM lights do not come on.
However CMP-13 does not seem to understand that as a 2020 change actually permits the unit equipment to be on a separate circuit, even if there is only a single lighting circuit for the area.

I don't have 2020 handy. Do they require, in that case, a relay be installed to drop power to the e-lights if the local lighting circuit fails?

 

[don_resqcapt19]

I don't have 2020 handy. Do they require, in that case, a relay be installed to drop power to the e-lights if the local lighting circuit fails?

No.

700.12(I)(2)
(3) The branch circuit feeding the unit equipment shall be one of the following:

• a. The same branch circuit as that serving the normal lighting in the area and connected ahead of any local switch
  
  
• b. Where the normal lighting circuit is served by one or more branch circuits, a separate branch circuit, provided with a lock-on feature, that originates from the same panelboard as the normal lighting circuits. The branch circuit disconnecting means for this branch circuit shall be provided with a lock-on feature.

• 
  
  Item (b) in the 2017 code only permitted a separate circuit for the unit equipment where there were 3 normal lighting circuits for the area. The language in 2020 says you can use the separate circuit where there are "one or more" normal lighting circuits. I submitted a PC to fix this, but they rejected the PC. Not sure if it got fixed for the 2023 or not. We will see in about a month when the first draft report is published.
  
  

 

[hillbilly1]

Usually the manufacturer prohibits it from being on a different circuit in the instructions, just needs to be ahead of the switch. The inverter shares the same neutral as the driver or ballast. At least the engineer didn’t put them on a smart breaker. I had that issue at a distribution center! No way to get ahead of that! LOL!

 

[kwired]

For something that should switch to battery when lights fail - it needs to be connected to lighting circuit.

Exit sign may or may not even be required to be illuminated - something outside NEC so I can't give definite answer. Photo luminescent exit signs are a possible allowance for them to be non powered though.