409.110 Opinions Sought

[eric9822]

We are in the early stages of a turnkey industrial control system replacement project. The vendor is supplying all the I/O enclosures and is building them to comply with UL 508A. They have asked us if we need to actually have them listed and "stickered" because they did not plan on supplying drawings as required, only termination lists. Our initial thought was maybe not since our AHJ does not typically require UL listing for this sort of thing as long as the components are UL listed. While researching the issue I also re-read 409.110 which states (amongst other things):

409.110 Marking. An industrial control panel shall be
marked with the following information that is plainly visible
after installation:
(5) Electrical wiring diagram or the number of the index to
the electrical drawings showing the electrical wiring
diagram.


At that point I said UL508A "stickering" may not be required but since you need to supply drawings anyway and you are building them in a UL panel shop you might as well apply the stickers. The vendor replied they have no plans to provide drawings and the electrical termination lists are equivalent. I disagree since the code does not state drawings or equivalent. Am I seeing this correctly?

 

[skeshesh]

I agree with your interpretation but the issue of who is the party responsible for providing the drawing is hairy.
I'll give you an example - on Fire Alarm jobs, there are times that we are required per client or depending on the project (schools, etc.) to provide detailed wiring diagrams. Other times we only show device locations and "routing" of raceways and the installer is responsible for providing wiring details. I have had some helpful contacts that represent known manufacturers and some of them were able to provide wiring diagrams while others did not have them.
Now, my question to you is if the manufacturer does not provide you with a wiring diagram yet a reference to such is required, do you think they are responsible for providing such a document or is it the engineer's responsibility to produce a wiring diagram based on their termination matrix?

 

[eric9822]

Thanks for the input skesesh. The project is turnkey so the vendor is responsible for design engineering, procurement, and installation. The contract does not explicitly state that drawings will be provided but it does state that the installation will meet all applicable codes including the NEC. Based on that I believe the vendor is responsible for supplying the drawings as required by 409.110. Their proposal is to supply an index pointing to the supplied termination schedules. My response was 409.110 states "electrical drawings or an index to the electrical drawings", not an index to what ever you want. Thanks again.

 

[skeshesh]

Thanks for the input skesesh. The project is turnkey so the vendor is responsible for design engineering, procurement, and installation. The contract does not explicitly state that drawings will be provided but it does state that the installation will meet all applicable codes including the NEC. Based on that I believe the vendor is responsible for supplying the drawings as required by 409.110. Their proposal is to supply an index pointing to the supplied termination schedules. My response was 409.110 states "electrical drawings or an index to the electrical drawings", not an index to what ever you want. Thanks again.

Sorry you did mention it's turnkey in your OP, dont know how I overlooked it... It seems to me that you're on the right track - you can also bring up that a document that simply shows the terminals and associated terminations and such would not contain information about wiring, raceways, boxes and other pertinent details of installation.

 

[jim dungar]

If these are really just I/O panels, then there is no internal wiring of them except from field wiring terminal blocks to device terminals, as such they would not have a 'wiring diagram' that shows device interconnections.

I see nothing in 409.110(5) that this type of panel to be supplied with anything more than a Point-to-Point listing of terminations. Although I might have a slightly different opinion if these panels include connections for 'supply circuits'. But, in reality a simple statement like 'see drawing XYZ for more information' would meet the intent of "identification number of a separate electrical wiring diagram" or a nameplate like 'Panel RST' meets the requirement of "a designation referenced in a separate wiring diagram"

...would not contain information about wiring, raceways, boxes and other pertinent details of installation.

None of these items are normally part of 'wiring diagrams', they are part of installation instructions.

 

[eric9822]

If these are really just I/O panels, then there is no internal wiring of them except from field wiring terminal blocks to device terminals, as such they would not have a 'wiring diagram' that shows device interconnections.

I agree that there is not a lot of internal wiring. There is however a significant amount of wiring from the I/O termination assemblies to the field devices. Some of these cabinets have over 600 I/O points. Is the wiring from the cabinet to the field not included in the drawing requirements in 409.110(5)?

I see nothing in 409.110(5) that this type of panel to be supplied with anything more than a Point-to-Point listing of terminations. Although I might have a slightly different opinion if these panels include connections for 'supply circuits'. But, in reality a simple statement like 'see drawing XYZ for more information' would meet the intent of "identification number of a separate electrical wiring diagram" or a nameplate like 'Panel RST' meets the requirement of "a designation referenced in a separate wiring diagram"

The I/O cabinets will have externally supplied supply power. No drawings are planned to be supplied for that either.

 

[jim dungar]

Is the wiring from the cabinet to the field not included in the drawing requirements in 409.110(5)?

I cannot find any justification for it to be included.
The last sentence of 409.2 clearly says that the 'industrial control panel' does not include the controlled equipment (which I take to mean the field equipment). And, again, 409.110(5) clearly refers to diagrams separate from the control panel.

 

[skeshesh]

After reading the section over again as well as Jim's insight I'm inclined to agree with him. BUT man does that sound like a pain should there be need for information in the future or what? No drawings showing connections to hundreds of devices on the downstream and no indication of the supply side circuits or wiring? Sounds like a nightmare somewhere down the line.

 

[eric9822]

I cannot find any justification for it to be included.
The last sentence of 409.2 clearly says that the 'industrial control panel' does not include the controlled equipment (which I take to mean the field equipment).

Fair enough, field equipment is excluded. But what about the wiring from the I/O to the field equipment? It's wired to the panel.

And, again, 409.110(5) clearly refers to diagrams separate from the control panel.

I am not sure what you mean here. All I see is drawings required.

Thanks again for the input. We are having a pretty good debate internally.

 

[jim dungar]

I see the NEC as being interested only with the 'internals' of the panel.

Project/equipment acquisition specifications are what get you 'wiring diagrams' for field devices and interconnects between panels.

 

[jim dungar]

I am not sure what you mean here. All I see is drawings required.

409.110(5) contains three instances of the word "or", therefore it is providing options. Two of those options use the word 'separate' as a modifier to 'wiring diagram'. There is no absolute requirement for drawings to be supplied by a manufacturer.

 

[eric9822]

409.110(5) contains three instances of the word "or", therefore it is providing options. Two of those options use the word 'separate' as a modifier to 'wiring diagram'. There is no absolute requirement for drawings to be supplied by a manufacturer.

True. Thanks.

 

[pfalcon]

Your hope lies in the issue of the panel being purchased as a Turnkey installation. Wiring diagrams per 409 are required or the equipment is not usable. A Turnkey vendor must provide all essentials to make it operable.

Long Term:
1) Purchase a copy of NFPA79, you can preview the standard on their website.
2) Adopt the NFPA79 for all future purchases including Annex D which is optional to the standard.

Short Term:
3) Go and see the NFPA website for NFPA79 ANNEX D
4) Argue that it is an example of a professional wiring diagram for an industrial control panel.
5) When they refuse out of hand, and they will, pointedly ask them "What industrial standard are you applying to the diagrams and the panel?"

Take this stance, which is pragmatic::
Your industry will determine the odds of being inspected. Your industry will determine the odds of someone getting hurt such that OSHA will get involved. Presume it might be this machine on an electrical circuit. Think about the questions that OSHA can ask that will magnify the fines and prevent your company from defending itself.

"What electrical standard did you build the industrial control panel to?"
The NEC and UL508A are great as far as they go. But neither really address the problems of industrial control. Do you have an internal standard? If you're relying on the vendor, does he have a documented standard?

"Was the wiring diagram sufficient for the serviceman to handle the job safely?"
"What criteria do you have to demonstrate the diagram is sufficient?"