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Safety Requirements on 120Vac Board

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I've designed a board with a few relays that switch 120VAC. I have the normally open side of the relay connected to a current limiting resistor and opto-isolator. Do I need to worry about single fault failure for safety testing? If so, can I just put two resistors in series?


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By safety testing, you mean official certification?

Doesnt the current limiting resistor interfere with function? If it doesnt, isnt it too low to be protective?
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Yes I mean official certification. I'm not exactly sure what you mean by 'interfere with function'. For certification, will I need to worry about single fault failure?
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