210.5C1

[elec58]

Needed some clarity on 210.5C1 I installed some branch circuits from a 120/208 panel and inspector wants all circuits phase taped, including all M/C cable terminations at each receptacle, because there are 480 volt panels located in other stores on the premises. There is only 120/208 in the store we are wiring but this is an outdoor mall with attached spaces being rented. so we assumed it did not apply since our space did not have 480 Were we incorrect in our interpretation of 210.5 requirements?

 

[charlie b]

I need look no further than the title of 210.5(C)(1): "Branch circuits supplied from more than one nominal voltage system." That phrase does not apply to your situation. That is because, within the "premises" supplied by your panel, there are no branch circuits being supplied by a different nominal voltage system. The inspector has interpreted this installation incorrectly.

 

[elec58]

I need look no further than the title of 210.5(C)(1): "Branch circuits supplied from more than one nominal voltage system." That phrase does not apply to your situation. That is because, within the "premises" supplied by your panel, there are no branch circuits being supplied by a different nominal voltage system. The inspector has interpreted this installation incorrectly.

Spoke with inspectors senior inspector who agreed with him the word premises is the sticking point They say premises refers to entire mall since all stores are connected with demising walls. not sure where to go from here if phase taping all my M/C was easy I would just comply with correction but it would be very time consuming.

 

[tortuga]

I need look no further than the title of 210.5(C)(1): "Branch circuits supplied from more than one nominal voltage system." That phrase does not apply to your situation. That is because, within the "premises" supplied by your panel, there are no branch circuits being supplied by a different nominal voltage system. The inspector has interpreted this installation incorrectly.

I agree with Charlie, there can be no ambiguity unless some panels are grouped in one electrical area.

The other stores that have 480 surely also have 208Y120 and there is a posted color code somewhere.
What are the posted color codes for the two systems?

I cant remember seeing a 480 system that uses black as a phase color, white for a neutral yes, black as a phase not really. I am sure people do it though.
Did you use Brown /Orange / Yellow MC cable for some 208Y120 3 phase receptacles or something?

 

[charlie b]

What you have to gain (or the tenant's future electrical worker has to gain) is nothing more than knowing whether a given outlet is powered by your phase A or one of the other two. But they won't need to know that while standing at the outlet. They can learn that when they go to the panel to turn off the circuit. There is nothing to gain by adding phase taping.

Now let's get down to the real issue. The inspectors are wrong in saying that the word "premises" is the sticking point. The rule does not use that word in isolation. Rather, it uses the three word phrase, "premises wiring system." That phrase has a definition in article 100. Here, then, is the critical question: does the utility provide a separate meter just upstream of your 120/208V panel? Put another way, is your panel a "service panel"? If so, then article 100 would tell us that your tenant space has its own "premises wiring system," because that phrase starts at the service and ends at the outlet. Therefore, your premises wiring system (i.e., your tenant's space and no other tenant's space at the mall) does not have branch circuit wiring from more than one nominal voltage system. QED

(Aside: Sadly, if you were to tell us that the utility provides its service to a central electrical room elsewhere in the mall, and that your panel gets power from a feeder and not from a service, I would have to side with the inspectors.)

 

[elec58]

It is fed from a transformer within the space.

 

[elec58]

I agree with Charlie, there can be no ambiguity unless some panels are grouped in one electrical area.

The other stores that have 480 surely also have 208Y120 and there is a posted color code somewhere.
What are the posted color codes for the two systems?

I cant remember seeing a 480 system that uses black as a phase color, white for a neutral yes, black as a phase not really. I am sure people do it though.
Did you use Brown /Orange / Yellow MC cable for some 208Y120 3 phase receptacles or something?

only one single phase 208 circuit going to roof RTU Not sure i understand the logic anyway why does it matter what phase a typical receptacle is on even if there is two voltages in same space, if you use red, black, blue, there are fourteen places the wire could be landed and you already know its a 120 receptacle by looking at it.
Are we required to phase tape M/C cable?

 

[elec58]

OK got it Thanks for the reply

 

[charlie b]

Charlie could you elaborate a little on this statement, not sure what you are referring to with electrical room elsewhere. We are getting power from metered switchgear to our transformer disconnect.

The article 100 definition of "premises wiring system" tells us that this concept begins at the service point. So I asked whether the power to your tenant's facility is, or is not, a "service," as that word is defined in article 100. Does the utility company provide power to your tenant? Or does the utility provide power to the building as a whole, with the service equipment located in a central electrical room, and with power to each individual tenant being routed via a "feeder" from the service switchgear? What I am driving at is this: if your tenant gets power directly from the utility, if the power source is literally and legally described as a "service," then your tenant has a "premises wiring system" that is completely separate from any other "premised wiring system" in the building. In that case, the inspector's claim that the building has more than one voltage rating, and therefore you have to color code your conductors, would be incorrect. But you can't use this argument if the power to your tenant is a "feeder," and not a "service."

 

[elec58]

The article 100 definition of "premises wiring system" tells us that this concept begins at the service point. So I asked whether the power to your tenant's facility is, or is not, a "service," as that word is defined in article 100. Does the utility company provide power to your tenant? Or does the utility provide power to the building as a whole, with the service equipment located in a central electrical room, and with power to each individual tenant being routed via a "feeder" from the service switchgear? What I am driving at is this: if your tenant gets power directly from the utility, if the power source is literally and legally described as a "service," then your tenant has a "premises wiring system" that is completely separate from any other "premised wiring system" in the building. In that case, the inspector's claim that the building has more than one voltage rating, and therefore you have to color code your conductors, would be incorrect. But you can't use this argument if the power to your tenant is a "feeder," and not a "service."

OK got it Thanks for the reply