Mike Dolt Enterprises
Mike Dolt Enterprises
User: JohnDS, Location: Suffolk, Long Island
Asked on: Thursday, April 28, 2011 at 4:16 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:45 am EDT
Question: Hey guys. I have a 240v Hot Tub to wire and the name plate says:Max Current Draw: 48ampsI just want to double check and make sure I am sizing the wire properly.48amp x 1.25 = 60ampI am going to use a 60a breaker with #4 wires but I'm a little confused because after the 125% rule above, the calculation lands right on the size breaker I am using. Should I go to the next size up or should I use a 60amp breaker with #4 wire?
According to the National Electrical Code (NEC), the wire size and breaker size should be calculated based on the continuous load, which is 80% of the maximum current draw in this case.Continuous load = 48 amps x 0.8 = 38.4 ampsUsing the 125% rule:Breaker size = 38.4 amps x 1.25 = 48 ampsWire size = 48 amps x 1.25 = 60 ampsSince the calculated wire size is the same as the size of the breaker you plan to use (#4), you have selected the correct wire size.
Therefore, you should use a 60-amp breaker with #4 wire for the 240-volt hot tub.
It is not necessary to go to the next size up in this case, as the wire you have chosen has the correct ampacity for the load. Flag for review