Breaker Question

[stevo wis]

H Folks,

I am replacing a hot tub. The old setup had a 60 amp 220 breaker at the main panel wired with 8 guage wire to an outside disconnect that did have a 40 amp 220 gfci, then on to the tub.

The new tub calls for a 50 amp breaker at the main, then a 30 amp double pole gfci and and a 20 amp single pole gfci breaker.


I installed the two gfci at the disconnect. Is it necessary to swap out the 60 amp for a 50 amp in the main panel?

thanks,

Stevo

[Aaron Inami]

I would probably say that you can still run 60A breaker at your main panel as long as the electrical line from the main panel to the hot tub sub-panel is spec'd to support 60A. I'm assuming 8 awg would still be fine here. The sub-panel breakers for double-pole 30A and single-pole 20A should have adequate wire after them (i.e. 10awg).

The callout for 50A at the main is likely minimum recommended/required.

[Jim Becker]

I agree with Aaron. The supply to the hot tub subpanel can be heavier than the 50a required which is a minimum. No need to change it. The two circuits at the hot tub end in that subpanel take things from there.

[Bill Dufour]

#8 wire is undersized for 60 amps. I have no idea if a hottub is considered a hot service area ,like an attic; and needs further ampacity derating?
Bill D.

#8 NM-b is 40 amps. THHN is 50 amps

https://www.cerrowire.com/products/r...pacity-charts/

[Cameron Wood]

I agree with Bill Dufour above- the current set up does not meet code, and the proposed set up does not either.

In practice, the risk is low IMO, since any issue at the tub would trip the lower rated breaker, and a problem with the wire going to the tub disconnect would most likely be a direct short i.e. conduit cut by digging, that would trip the panel breaker anyway.

If it was my personal situation, I might leave it, but as a contractor, I would not.

[Frank Pratt]

Yep, #8 is too small for a 60A circuit. That's on whoever did the initial installation, but you need to change out that breaker because it's a fire hazard as it is now.

[Cameron Wood]

Yep, #8 is too small for a 60A circuit. That's on whoever did the initial installation, but you need to change out that breaker because it's a fire hazard as it is now.

Actually the wire would need to be changed to use a 50 amp breaker...

[Rollie Meyers]

Actually the wire would need to be changed to use a 50 amp breaker...

That depends on the conductors currently in use, as said already NM sheathed cable is sized in the 60°C column of table 310.15(B)(16) so 8 AWG is 40A, but if THHN/THWN 8 AWG is 50A, THWN is required for wet locations.

[Cameron Wood]

That depends on the conductors currently in use, as said already NM sheathed cable is sized in the 60°C column of table 310.15(B)(16) so 8 AWG is 40A, but if THHN/THWN 8 AWG is 50A, THWN is required for wet locations.

You're right. If the wiring is modern, it's probably THHN, so that would work.