Emergency Lighting - 208V?

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
I am currently researching for a project that has LED which can utilize 208V single phase. Using 208 is the best option due to voltage drop and quantity of fixtures. The problem is... we need to have emergency lighting in the area which the lights serve. Has anyone heard of a 208V emergency wall pack light? I'm asking because (2017) 700.12(F)(2.3)... (2020) 700.12(I)(2.3) requires I have the emergency lights on the same circuit serving the normal light in that area.
 

tortuga

Senior Member
Location
Oregon
Occupation
Electrical Design
Why not just bump up to 277 with a boost autotransformer? Its a more standard 'lighting' voltage.

 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
If a 120V/208V MWBC powers both 208V normal lighting and 120V emergency lighting are they being served by "the same branch circuit" as specified by 700.12(I)(2)(3)a. ?
I would think so, because the definition of "Branch Circuit, Multiwire" in Article 100, Part I begins with: "A branch circuit that consists of two or more ungrounded conductors ..."
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
I believe a 120V/208V MWBC would also meet the intent of 700.12(I)(2)(3)a. because if the 208V normal lighting goes off because the MWBC's breaker trips, then the 120V for emergency lightIng will also go off.
 

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
I believe a 120V/208V MWBC would also meet the intent of 700.12(I)(2)(3)a. because if the 208V normal lighting goes off because the MWBC's breaker trips, then the 120V for emergency lightIng will also go off.
I was considering this... but (and this may sound silly) I was worried about an issue with a potentially unbalanced neutral. Although the EM light draws minimal to keep the batteries charged, there would be a unbalance. Thoughts?
 

kwired

Electron manager
Location
NE Nebraska
I was considering this... but (and this may sound silly) I was worried about an issue with a potentially unbalanced neutral. Although the EM light draws minimal to keep the batteries charged, there would be a unbalance. Thoughts?
If you have multiple units balance them across the neutral as much as possible.
 

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
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