Mike Dolt Enterprises
Mike Dolt Enterprises
User: ajpslp, Location: Chapel Hill, NC
Asked on: Wednesday, March 30, 2011 at 4:34 pm EDT
Answered on: Tuesday, May 14, 2024 at 3:30 am EDT
Question: I had an electrician in NYC area wire up for a hot tub which is coming htis week . Here is the setup . I have in my attic (already in attic previously) wire that states 6-3 g type mn-b 600 volts e108168, this is then into a box in attic which the electrician added to so it reaches yard the following wire- butler / holley 12/4/10 e18679 romex simpull awg 6cu 3 cdr with awg10ground type nm-b 600 volts . From here it goes out the soffet of my house into the PVC type - gray pipe for underground type running . The wire inside the pipe then goes into a Sub panel which will have a 60 amp breaker in it for the spa. Is this ok , on the hot tub forums one person said something about ampicity and that the nm-b wire can overheat and catch my house on fire. The wire is all 6/3. The hot tub draws 45 amps when everything is running. Just want to make sure im ok before is all done. Am i safe?He also stated something about conductors and, derating the wire due to heat in attic and 55 amps is most for that wire .. any help is great.. Spoke to 2 other electrical guys who said it was fine ..?????
Yes, it appears that your setup is generally safe.Wire Specifications
6-3 g type mn-b 600 volts (attic to outdoor box): This wire is rated for 60 amps. 12/4/10 e18679 romex simpull awg 6cu 3 cdr with awg10ground type nm-b 600 volts (outdoor box to subpanel): This wire is also rated for 60 amps.
Subpanel
60 amp breaker: This is appropriate since the hot tub draws 45 amps when running.
Ampacity and Derating
The concern raised about ampacity and derating due to heat in the attic is valid. However, in your case, the wire is rated for 60 amps, and the hot tub draws 45 amps. This means that there is some margin for safety.* Additionally, derating for heat is typically not required for short runs like the one from the attic to the outdoor box.
Conclusion:
Based on the information provided, your electrical setup appears to be safe for your hot tub. However, it is always advisable to have a qualified electrician inspect and approve the installation before using the hot tub. Flag for review