I don't know Jim, if you to this thread
Installation instructions are considered to be a part of the UL Listing.
You can see ULs position is all instructions are mandatory.
Larry's position seems to be all instructions apply unless they do not make sense, I want to find the exception that allows commonsense.
Bob, I like the common sense approach as well (really- I do!). The question then becomes how do you determine what is "universal common sense" over what someone else thinks is "common sense". Surely you don't believe that everyone thinks in an identical manner. Do you?
In the electrical system construction world, there are so many iterations of possible installation scenarios, that it is virtually impossible for any manufacturer to address all of them in their design and performance of a product. The NEC provides a general sense of the requirements, but even then, the NEC cannot (and does not) address every possible application possibility. This is where the AHJ comes into play (hopefully with the "common sense" we are talking about).
When UL or any other NRTL sets out to "list" a product to a particular specification, they (in all their common sense wisdom), review the manufacturers instructions (if provided), determine and evaluate the 'critical or necessary' information, and then install & test accordingly.
If the Mfr. has a major problem with the critical information that they need to provide on a written instruction or label, they must correct it before the NRTL will list the product. The NRTL 'assumes' that the installer will heed the instructions with the product, and will stand by its listing of the product. The moment that the installation, application, or use of the product deviates from the intended use or written instruction from the manufacturer, they will not be 'liable' for any product failure, property loss, or injuries. I would bet that the same thing will go for the manufacturer.
I am not trying to take the side of any NRTL, I am merely stating what information they use for the listing process.
I certainly can appreciate and understand the myriad of difficulties you and others have on any given day to get the job done. I also respect the fact that you are handed a 'black and white' document and asked to unconditionally apply it to a Technicolor world. Unfortunately, 'one size fits all' does not apply, and at the end of the day, the AHJ has final say no matter what version of common sense we all have.
