Which wiring method?

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lquadros

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There is an electronic controller 120VAC, 0.5Amps max. This controller came with a 3 conductor cable with a 120V, 3 prong plug. I installed this controller on the side wall of an industrial control panel. I used suitable strain relief to pass through into the panel and terminated it to a 2 amp breaker in that panel. I had to cut off the 3 prong plug. The field inspector failed this installation and suggested to install a flexible conduit, and use single conductors. Do you think it is an error to permanently connect the original cable that came along with the controller? Your feedback is much appreciated. Thanks in advance.
 
Re: Which wiring method?

What you did is very common in the industrial control world, and I am not convinced there is any NEC rule against doing so. This is clearly not part of the premises wiring.

You could have just installed an outlet on the outside of the box and plugged the cord in there.
 
Re: Which wiring method?

How about asking the field inspector to cite the basis (i.e., NEC Article and Paragraph) for the violation?
 
Re: Which wiring method?

I just realized he used the phrase "field inspector". I wonder if he meant a UL type inspection.

UL 508a para 28.5.3 specifically requires that any cord passing through an enclosure wall must have a strain relief. It would be silly to have a strain relief requirement if this was not allowed.
 
Re: Which wiring method?

Flexible cords are permitted to be permanently connected to boxes or fittings where specifically permitted by the Code
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If the above statement is true then your inspector may not see where the code gives permission
 
Re: Which wiring method?

Originally posted by petersonra:
This is clearly not part of the premises wiring.
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How do you figure that?

Premises Wiring (System). That interior and exterior wiring, including power, lighting, control, and signal circuit wiring together with all their associated hardware, fittings, and wiring devices, both permanently and temporarily installed, that extends from the service point or source of power, such as a battery, a solar photovoltaic system, or a generator, transformer, or converter windings, to the outlet(s). Such wiring does not include wiring internal to appliances, luminaires (fixtures), motors, controllers, motor control centers, and similar equipment.
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That wiring he describes is not internal to the controller etc.
 
Re: Which wiring method?

He probably feels that by cutting off the manufacturers plug you altered the listed installation of the product.I would say the burden of the proof is in your lap since you altered the plug then to show it is still ul listed would be yours to prove IMHO.
 
Re: Which wiring method?

The installation instructions that are provided may permit the attachment plug to be removed. With that being said, cords in general are supposed to be visible for their entire length as per the UL White Book listing. UL 508, and NFPA 79 also have requirements for installers to follow as guidelines.
 
Re: Which wiring method?

Cutting off a plug can not change the UL listing of a device. However, it may change the manufacturers installation instructions.

The UL Listing only says that a device met the listing requirements when it left the factory. It is up to the AHJ to decide if an installation is acceptable. The AHJ can use a "listing mark" to aide when approving a device.

Any time you field cut a hole (i.e. for a conduit entry) you technically have modified an enclosure to the point where it may not meet the original listing requirements. The NEC allows the AHJ to pass judgement on whether the field cut hole has been properly located, plugged, and/or sealed.
 
Re: Which wiring method?

Originally posted by iwire:
Originally posted by petersonra:
This is clearly not part of the premises wiring.
Click to expand...
How do you figure that?. . . That wiring he describes is not internal to the controller etc.
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I agree with Bob. Let me take it from an after-the-fact inspection, and let's for a moment forget UL issues and "who built what when" questions.

I look at this installation today. I see an "industrial control panel" that has a "controller" attached to it via a small piece of conduit (or strain relief or nipple or something). Then I read this:
Such wiring does not include wiring internal to appliances, luminaires (fixtures), motors, controllers, motor control centers, and similar equipment.
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I view this installation as being either "controllers" or at least "similar equipment." I conclude that the wiring internal to this beast, including the wiring between the original "industrial control panel" and the new "controller," is excluded by the definition of "premises wiring system."
 
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