20 amp 240v continuous load calculations

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Chuck B

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I am installing three (3) digital wall heaters in my cottage on a 240v 20 amp circuit. My calculation at 80% is 3,840 Watts.

However my plan is to install (2) 1,600 volt and (1) 800 volt heaters (wall units with built in thermostats) which places me at 16.666 amps and a 4,000 watt draw on the 20-amp circuit.

It is likely all heaters would run simultaneously in my northern Michigan cottage.

Does the additional .6666 amps over the 80% 16 amp calculation present a safety or CB trip problem in practice.

Thanks.
 
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Jadnashua

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On items that can be expected to be on continually, generally, the 80% rule does apply. It's actually calling for the circuit to be 125% of the load if it could be continuous for 3 or more hours, which when you look at it another way, equals 80%.
 
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