Bob is correct, but only up to a point. In the US and Canada, public utilities are exempted from the National and Canadian Electrical Codes for equipment used on their contiguous property. The thought behind that was that these organizations have enough resources to do their own protection.
Hence, UL1950/CSA950 are not mandatory for such equipment. However, there are in to-day's environment a lot of service providers who are NOT public utilities. They use the same equipment as the utilities but are not exempt. I suspect that some of them don't know. Therefore, they may seek some sort of assurance, if only for the sake of their insurance coverage, that the equipment being used has been evaluated. Conformity Assessment Bodies in the USA and Canada offer programmes where equipment can be evaluated against whatever it is that you want it evaluated against. They have what they call "Desk Standards", documents that were never published but that are used to evaluate products for which there are no public standards. Remember, the Conformity Assessment Bodies do not claim that a product that they evaluated is safe. Very wisely, they only state that the product has been evaluated against certain requirements and met those requirements. The mark you get for being evaluated against something else than a public standard, may be a different mark than the one you get for meeting the requirements of a public standard. The service you are being provided may be called something different than listing or certification. I'm not sure what they call what. This offers industry a degree of flexibility that is needed in certain cases. Don't expect to be warmly received if you try and get a special evaluation for something for which there is a public standard. They don't just do this willy-nilly. Ciao, Vic
