Cord and Plug Cord for Overhead Door Operator Disconnect?

[ericwg]

I've got an apparatus bay for a fire station design I'm working on which will have 6 overhead sectional doors, hence 6 operators. In most our past designs, there was a sub-panel within the apparatus bay, which meant we used the branch ckt OCPD as the disconnecting means for the overhead door operators, typically 115V-1/2 HP. As far as wiring, at each operator we typically install a recessed j-box in the wall behind the operator or in the ceiling just above it, with 3/4" seal-tight connected to the face of it which then runs to the operator. In this new design I'm working on, the sub-panel is no longer located within the apparatus bay. Thus, it is not within sight of the operators and I cannot use the branch ckt OCPD as the disconnect. I was going to employ the same j-box and seal-tight except that adjacent to the j-box I was going to add a second box to house a 20A/1HP rated general snap switch with a lockable wall plate cover on it. Going this route I know I'm code compliant as far as the disconnect is concerned. I had another idea which I thought would simplify things a bit. I thought I might just install a 125V/20A/1HP simplex receptacle in the j-box I normally connect the seal-tight to. Then, I could have the contractor construct a 12awg SOOW cord of adequate length, hard-wired at the operator, with a 125V/20A/1HP rated plug on it, which could connect the operator to this receptacle. The question is, if I went this route, would this "cord and plug" be suitable to use as a disconnect? As I read through 422.31, 422.34, and 430.109(F), one minute I convince myself it's perfectly fine, then a few minutes later I think maybe not. Thoughts? Appreciate it if you could include whatever code section goes along with your position.

 

[hbiss]

How do the manufacturer's instructions say it should be connected? If it allows a cord and plug you can do it. I suspect it only shows hard wiring though.

110.3(B) Installation and Use. Equipment that is listed, labeled, or
both, or identified for a use shall be installed and used in
accordance with any instructions included in the listing, labeling,
or identification.
Informational Note: The installation and use instructions may
be provided in the form of printed material, quick response
(QR) code, or the address on the internet where users can
download the required instruction.

-Hal

 

[ericwg]

How do the manufacturer's instructions say it should be connected? If it allows a cord and plug you can do it. I suspect it only shows hard wiring though.

110.3(B) Installation and Use. Equipment that is listed, labeled, or
both, or identified for a use shall be installed and used in
accordance with any instructions included in the listing, labeling,
or identification.
Informational Note: The installation and use instructions may
be provided in the form of printed material, quick response
(QR) code, or the address on the internet where users can
download the required instruction.

-Hal

That’s a good question. Unfortunately, the IOM provides very little detail. It doesn’t clarify hardwired vs cord. In case you’d like to see for yourself, below I will share the “Input Wiring Diagram”, two instruction pages which contain information related to wiring, and the connection diagram. Given the way the input power terminal block is shown in the connection diagram, one could argue that implies hardwired, but IMO it’s not definitive.

 

[hbiss]

4- Any wire connected to the control panel must be protected by conduit or other means to ensure the safety and permanency of the wiring.

-Hal

 

[ericwg]

4- Any wire connected to the control panel must be protected by conduit or other means to ensure the safety and permanency of the wiring.

-Hal

4. "Any wire connected to the control panel must be protected by conduit or other means to ensure the safety and permanency of the wiring." Two questions. 1) Do you think that a properly jacketed cable with a UL listed and properly rated plug would not be considered sufficient to ensure the safety of the wiring? 2) What was the true intent of you sighting this section? Were you focusing on the "permanency of the wiring", to reflect beyond the the wiring itself and extend to a cord and plug connection vs a hardwired connection, which cannot be as easily removed? FYI, I will reach out to my contact at Cookson to see what they say.

Humor me for a second and assume that the language in the IOM is too vague or is open to interpretation such that we cannot rely on it to allow or disallow my desire to employ a cord and plug connection. Based solely on the code, what do you think it would allow in this instance?

 

[hbiss]

Do you think that a properly jacketed cable with a UL listed and properly rated plug would not be considered sufficient to ensure the safety of the wiring?

No, especially when they seem to be comparing to conduit. I think MC or Greenfield would be comparable.

-Hal

 

[ericwg]

No, especially when they seem to be comparing to conduit. I think MC or Greenfield would be comparable.

-Hal

I see. Fair enough. Nevertheless, I ask again, could you please answer the last question from my previous post:

"Humor me for a second and assume that the language in the IOM is too vague or is open to interpretation such that we cannot rely on it to allow or disallow my desire to employ a cord and plug connection. Based solely on the code, what do you think it would allow in this instance?"

 

[roger]

I see. Fair enough. Nevertheless, I ask again, could you please answer the last question from my previous post:

"Humor me for a second and assume that the language in the IOM is too vague or is open to interpretation such that we cannot rely on it to allow or disallow my desire to employ a cord and plug connection. Based solely on the code, what do you think it would allow in this instance?"

Hal has already given you the article section that will tell you what you have to do and that is 110.3(B). You may not like it and it might not have any real reason behind it but it is what can provide an AHJ or Insurance Carrier all they need to reject or cause grief down the road.

 

[ericwg]

Hal has already given you the article section that will tell you what you have to do and that is 110.3(B). You may not like it and it might not have any real reason behind it but it is what can provide an AHJ or Insurance Carrier all they need to reject or cause grief down the road.

I am well aware of the code reference Hal provided and understand its implications. With all due respect to you and Hal, though, I do not think the content provided in the Manufacturer's IOM is crystal clear and not open to other interpretation. Can you say with 100% certainty what they meant when they said "or other means"? It was Hal's opinion that the SOOW cable w/ a UL rated plug would not be equivalent to conduit. On the other hand, he "thought" MC or Greenfield would be comparable. That is his opinion, I understand how he came by it, and I totally respect it. Honestly, it's not about what I may or may not like. Hal voiced his opinion on the interpretation of the Manufacturer's language in the IOM. He raised a good point and as I said, I have already contacted the manufacturer to ask for additional clarification. What I am now asking is to consider for a minute that the manufacturer's "or other means" did include a cord and plug. For the purposes of my education on the relevant code section(s), would that cord and plug be acceptable? Are there other considerations or requirements I need to know about. This manufacturer produces operators of varying sizes (from 1/3 to 2HP and possibly greater), yet they have only the one IOM. Does the size of my operator come into play? I know I don't have to explain to you, just because a manufacturer says you can do something (or doesn't explicitly say you can't) means that to do so is code legal, particularly in my jurisdiction (CA). I hope I am making sense and you understand my intent. It is not to find some way out of a clear instruction or because I'm radically opposed to my original plan to install disconnects. I just want to know if the cord and plug idea is sound, which in this case may require a bit of supposition.

 

[mtnelect]

I kind of like Section 400.7 "Uses Permitted and Not Permitted" to keep "Electricians Gone Wild" with flexible cords on everything. My number one is flexible cords on furnaces.

 

[tom baker]

If you want to use a cord and plug, go for it. We have given you our perspective. The final decision is by the AHJ.
Or ask the AHJ first

 

[ericwg]

I kind of like Section 400.7 "Uses Permitted and Not Permitted" to keep "Electricians Gone Wild" with flexible cords on everything. My number one is flexible cords on furnaces.

I was not familiar with this section, which appears to now be 400.10 in the 2020 NEC. Thanks Michael. That section is pretty clear in that it states "Flexible cords and flexible cables shall be used only for the following...", which includes a list of 11 items. Section 400.10(A)(6) - "Connection of utilization equipment to facilitate frequent interchange" leaves a bit of room for interpretation, however, I would never claim it applies to my situation.