UL's interpretation of NEC 400.7 & 400.8

[designengineer]

I am working with UL to get UL Listing of projection screens powered by a flexible cord atttached to the screen case and a molded plug on the end of the cord. UL is okay with some of the products based on the way they are mounted, but they have said that if the product is attached to the wall or ceiling in a manor that requires a tool for removal, then it doesn't meet requirements of NEC 400.7. A couple of our screen models are attached to the wall using 1 screw at each end of the product. I have read 400.7 and I believe our screens mounted with 2 screws do meet 400.7.A.8 which reads as follows:

400.7 Uses Permitted
(A) Uses. Flexible cords and cables shall be used only for the following:
(8) Appliances where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance and repair, and the appliance is intended or identified for flexible cord connection.

I can't find anywehere in the electronic version of NEC 2008 where it defines what is meant by "ready removal" or that it means removal with out tools. I have argued with UL that one screw at each end is still "ready removal", but they keep coming back to the fact that removal of the screws requires a tool.

Is UL correct in their interetation of the NEC?

If no, is there any why to get any kind of opinion from the NEC on this issue?

 

[Cold Fusion]

... A couple of our screen models are attached to the wall using 1 screw at each end of the product. I have read 400.7 and I believe our screens mounted with 2 screws do meet 400.7.A.8 ...

...I can't find anywehere in the electronic version of NEC 2008 where it defines what is meant by "ready removal" or that it means removal with out tools. I have argued with UL that one screw at each end is still "ready removal", but they keep coming back to the fact that removal of the screws requires a tool.

Is UL correct in their interetation of the NEC?

If no, is there any why to get any kind of opinion from the NEC on this issue?

UL is a private company. They get to interpret the NEC anyway they want. You could even get a formal intrepretation from NFPA negating UL's position, and UL could still say, "That's not the criteria we use for our certification."

If you want their sticker - you're going to have to deal with their rules.

Now a couple of questions:

1. Who is mandating you use UL? There are other acceptable NRTL companies out there. Have you called any of them?

2. Have you given any thought to a minor redesign? Maybe use thumbscrews/wingnuts?

cf