Daniel
This happens to us all the time- customers require certifications that are not pertinent to their needs.As Richard says above, you need to get the standard and perhaps even ask the customer what sections apply. Read the spec and see if in fact there is something that may even vaguely pertain and see how that impacts your design. You can use that in your claim that you meet the standard.
You can try and persuade the customer the folly of their request. Experience has shown that that is normally a waste of time. (the customer is looking at the bigger picture and often believes (correctly or not) that if each element of the product is certified, then the sum must be certifiable as well with no additional effort.) You can try to ask who is going to adjudicate the compliance and then contact that agency and see if there is in fact anything for them to check. Somebody is going to have to pay for their time, so you had better include that in your budget. In one instance the only person in UL who had any understanding of this weird application of a UL standard was at the Los Angeles office. So we had to bring him up to Toronto, feed and house him for 3 or 4 days, while witnessing our compliance testing, which had been specially designed to meet the spec, even though it was a pointless exercise. The test was to see that in a short circuit condition the equipment did not overheat in a 24 hour period. However in the case of a shutdown a circuit breaker would trip so no power was dissipated at all- but we still had to check for the 24 hour period. How do you measure overheating- you place a muslin cloth over the item in question and if it catches fire it is too hot! (I am only exaggerating a little.)In your particular case, if it is just wiring, see if you can't find wire of a suitable gauge that meets ENxxxx and use it- it makes it a whole lot simpler.
Actually I see at the bottom of the link posted by Rick there is a link to a help "line". Maybe you could start there.
