Does the NEC apply? Part II - Dredging up from 2014.

[brycenesbitt]

I'm having a very similar "conversation" with a California based AHJ,
to the one @charlie b reported in this 2014 thread:

Does the NEC apply?

I recently had a disagreement with an AHJ in California. We ultimately found a mutually acceptable solution. But I would like opinions on the original issue. We are doing the electrical design for a restaurant. The designer of the kitchen equipment selected a table that had many different...

forums.mikeholt.com

I have a UL508A panelboard that "does some stuff" and "controls some things".
The AHJ is complaining about the listed control and switching functions of the UL508 panel board.

The Inspector's point of view was that,

• The internal components of the UL508A panel board fall under his jurisdiction.
• The wires from our UL508A circuit breaker(s) to the remote utilization equipment are NEC feeders.
• The entire setup falls under AHJ control not just at time of construction, but continuously, should downstream loads be added or removed (each would require a separate building permit). That the disconnects within the UL508A panel box must be relabeled per NEC 110.22, under AHJ supervision, every time a downstream subcomponent is altered, removed or added. That a fresh load calculation must be approved by the AHJ for each removal or addition.

My preferred point of view is that,

• We are supplying conductors to a UL listed appliance,
  and the internal switching functions are a UL matter not a AHJ matter.
• That the device itself needed to be considered in terms of total load, but not it's subcomponent loads.
• That subcomponent loads are utilization equipment not under the NEC.

But there's a wrinkle:
The downstream loads from the UL508A box could be cord and plug connected. But that's messy, and the subcomponents downstream are not super portable.
Instead we don't want to cord and plug connect them, we wish to hard wire them in conduit, for safety purposes, meaning using wiring attached to the floor or ceiling like any other conduit.


Thoughts? Anyone offering consulting services on code interpretation in California want to take on a job?

 

[jaggedben]

...
[*]The internal components of the UL508A panel board fall under his jurisdiction.

Not true.

[*]The wires from our UL508A circuit breaker(s) to the remote utilization equipment are NEC feeders.

Feeders or branch circuits? Regardless, I think he is correct they are within the scope of the NEC at least to a major extent if not entirely. The only way I'm see that not being the case is if the wiring specified as part of the listing of your panel and utilization equipment.

[*]The entire setup falls under AHJ control not just at time of construction, but continuously, should downstream loads be added or removed (each would require a separate building permit). That the disconnects within the UL508A panel box must be relabeled per NEC 110.22, under AHJ supervision, every time a downstream subcomponent is altered, removed or added. That a fresh load calculation must be approved by the AHJ for each removal or addition.
[/LIST]
My preferred point of view is that,

• We are supplying conductors to a UL listed appliance,
  and the internal switching functions are a UL matter not a AHJ matter.
• That the device itself needed to be considered in terms of total load, but not it's subcomponent loads.
• That subcomponent loads are utilization equipment not under the NEC.

But there's a wrinkle:
The downstream loads from the UL508A box could be cord and plug connected. But that's messy, and the subcomponents downstream are not super portable.
Instead we don't want to cord and plug connect them, we wish to hard wire them in conduit, for safety purposes, meaning using wiring attached to the floor or ceiling like any other conduit.
...

A lot to unpack there.

Broadly speaking the first part about permitting seems correct but I don't understand why it should be an issue.

The part about total load may depend on your panel being listed as an energy management system, depending on code cycle.

I don't understand why cord and plug connection should necessarily make a difference to the other questions. It just means your circuits may need to be sized to the largest equipment that could use the plugs.

 

[brycenesbitt]

I don't understand why cord and plug connection should necessarily make a difference to the other questions.

It's a load management thing. With hardwired utilization equipment, the UL508A control system knows exactly what's installed. With cord and plug equipment, it would have to guess. The reason it's relevant is that cord and plug connected extension cords, adapters, and utilization equipment are subject to UL listing but not the NEC. But then we'd have to create receptacles to plug them into....