Is there a "deceiving rating" provision in the nec

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Came across a few situations recently that got me thinking. Situation #1: Installed a service disconnect that had three switches as the main. The service conductors were 205 amp ampacity and it was a 400 amp MLO I-line panel. Inspector said I needed a plaque stating that the ampacity of the conductors was 205 amps. This is a state code (WAC) here in Washington that I did know about but it slipped my mind. i understand the theory that someone could see the 400 rated panel and connect a feeder or branch circuit that is more than 205 amps. Situation#2: House that is fed from a meter/main on a pedestal several hundred feet away. The house is fed with a 125 amp feeder not service conductors. The HO was picking up the panel and I told him to just grab a 200 main breaker panel because it only needs a disconnecting means not overcurrent protection and the 200 amp panel has more spaces and is basically the same price as a 125. Situation#3: You have some 15 amp rated circuits that for any number of reasons are 12 gauge going into the panel. When this happens I label them "15amp only". Is there anything in the NEC that would require labeling that the capacity/rating is not what it appears in these or similar situations?
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
Came across a few situations recently that got me thinking. Situation #1: Installed a service disconnect that had three switches as the main. The service conductors were 205 amp ampacity and it was a 400 amp MLO I-line panel. Inspector said I needed a plaque stating that the ampacity of the conductors was 205 amps. This is a state code (WAC) here in Washington that I did know about but it slipped my mind. i understand the theory that someone could see the 400 rated panel and connect a feeder or branch circuit that is more than 205 amps. Situation#2: House that is fed from a meter/main on a pedestal several hundred feet away. The house is fed with a 125 amp feeder not service conductors. The HO was picking up the panel and I told him to just grab a 200 main breaker panel because it only needs a disconnecting means not overcurrent protection and the 200 amp panel has more spaces and is basically the same price as a 125. Situation#3: You have some 15 amp rated circuits that for any number of reasons are 12 gauge going into the panel. When this happens I label them "15amp only". Is there anything in the NEC that would require labeling that the capacity/rating is not what it appears in these or similar situations?

Maybe not a bad idea, but not required by the NEC.
 

480sparky

Senior Member
Location
Iowegia
.......... Is there anything in the NEC that would require labeling that the capacity/rating is not what it appears in these or similar situations?


90.(C) Intention. This Code is not intended as a design specification or an instruction manual for untrained persons.

Qualified Person. One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training
to recognize and avoid the hazards involved.
 
90.(C) Intention. This Code is not intended as a design specification or an instruction manual for untrained persons.

Qualified Person. One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training
to recognize and avoid the hazards involved.

Right....But there are lots of codes that try to brother-in-law-proof electrical installations: handle ties on MWBC's.........
 
Came across a few situations recently that got me thinking. Situation #1: Installed a service disconnect that had three switches as the main. The service conductors were 205 amp ampacity and it was a 400 amp MLO I-line panel. Inspector said I needed a plaque stating that the ampacity of the conductors was 205 amps. This is a state code (WAC) here in Washington that I did know about but it slipped my mind. i understand the theory that someone could see the 400 rated panel and connect a feeder or branch circuit that is more than 205 amps. Situation#2: House that is fed from a meter/main on a pedestal several hundred feet away. The house is fed with a 125 amp feeder not service conductors. The HO was picking up the panel and I told him to just grab a 200 main breaker panel because it only needs a disconnecting means not overcurrent protection and the 200 amp panel has more spaces and is basically the same price as a 125. Situation#3: You have some 15 amp rated circuits that for any number of reasons are 12 gauge going into the panel. When this happens I label them "15amp only". Is there anything in the NEC that would require labeling that the capacity/rating is not what it appears in these or similar situations?

I see you talk about Washington state and the WAC, but your little icon says NY. Are you from NY?
 
There is also a set of brakes on every vehicle I ever owned, but I am an expert driver and have no need of those of course.

Not sure what your point is here. Are you for or against my original thesis that perhaps there should be a code for such things? I think it is a potentially pretty serious gap in the code, that I can repurpose a range circuit to run some 14 guage stuff and not have to label it.

I see you talk about Washington state and the WAC, but your little icon says NY. Are you from NY?

Mostly central NY, but i am licensed in and spend time in Seattle too. I like to mix it up a bit, keeps me from getting bored. Also, keeping track of three utilities' procedures and requirements is so fun, thought I should add three more to the mix ;)
 

iwire

Moderator
Staff member
Location
Massachusetts
I think it is a potentially pretty serious gap in the code, that I can repurpose a range circuit to run some 14 guage stuff and not have to label it.

My take on it is that the NEC expects only qualified people to be adding load to the system and inspections of that work to ensure code compliance.


What NEC sections eliminates the requirement to do Article 220 load calculations when adding load to an exsiting system?
 

kwired

Electron manager
Location
NE Nebraska
My take on it is that the NEC expects only qualified people to be adding load to the system and inspections of that work to ensure code compliance.


What NEC sections eliminates the requirement to do Article 220 load calculations when adding load to an exsiting system?

Kind of my thoughts also.



When you find 12AWG conductors landed on a 20 amp breaker - a qualified person would figure there was likely a good reason. Voltage drop is likely the first possibility. If those conductors go into a raceway with several other conductors then it should come to mind that maybe it had ampacity adjustments applied to it.

If I see a 200 amp panel with only 100 amp conductor supplying it, yes it catches my attention, but my next step is generally to check and make sure there is 100 amp overcurrent protection on the supply end and not to assume someone did anything wrong.
 
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