Hi. I am a building inspector in a small town of 5,000. We just changed to the 2020 NEC a few months ago and are working in some of the new rules. Our local electric co-op offers Type 1 Varistar,StormTrapper secondary class MOV surge arrestor but the head of engineering is not clear on his answer on whether it is code compliant. He says it is not UL listed but they have used it many times. He references code 230.67 which I am aware of but it just seems that he is being vague on if it really meets NEC standards. I was just wondering if anyone else had any experience with this unit. I really feel more confident with the Type 2 that is mounted on the service panel. Thanks for any help.
Gene
The 2020 NEC in Article 242 requires that all SPD’s be listed.
242.8 Listing.
An SPD shall be a listed device.
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Thank you Robert! That is what I was looking for. So the “engineer” didn’t know what he was talking about. That is why he was so vague in his answer. I have read these code book several times but I always seem to find something new each time. We will pass on their Type 1 and go with the approved Type 2 units.
Gene