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When can a UL 1077 listed device (supplementary protector) be used instead of a UL 489 listed device?

UL1077 Supplementary protectors are intended to provide equipment protection within appliances or other electrical equipment where UL 489 branch or feeder protection either is not required or is supplied by an appropriate UL489 listed device. Such equipment might include control transformers and electronic loads.


CTA-ID : 2022020
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