Section 404.(8)(B)

[porterh]

Section 404.8(B) requires a permanent barrier between adjacent devices where the voltage can exceed 300 volts between them. My question is, I have seen where a 120 volt circuit and a 277 volt circuit where brought in to a box. One would be for the lighting and the other for the restroom exhaust fan. With this type of situation can there possibly be 300 volta between the two devices? I thought that the 120 volts which is derived from a dry-type transformer, the two voltage systems would not see each other. Therfore there would not be a voltage potential between them. Please explain.

Thanks

porterh

 

[ryan_618]

Re: Section 404.(8)(B)

Yes, you need the divider, but the theory is more than I can explain. I'm sure one of the stronger theory guys can help explain it.

 

[al hildenbrand]

Re: Section 404.(8)(B)

Bathroom. . .Both voltages are referenced to each other through the common GES of the building. The phase relationship between the two voltages will determine how great the voltage between the two hot conductors is.