Type Z Conductors

[infinity]

I have a few generator jacket heaters that require a minimum of 125° C conductors in the heater junction box. The supplier has type Z, 150° C insulation, how would you size the conductors for a 4000W, 208 volt, 1Ø heater? From the panel to another junction box there will #10 THHN fed from a 30 amp CB which will splice to the type Z and then go about 15' to the heater JB.

 

[jumper]

Bump. I am curious.

 

[Dennis Alwon]

Looks like Table 310.15(B)(18) is the answer-- #14 wire-- IDK but that is what it looks like. But then 240.4 may make us use #10

 

[infinity]

But then 240.4 may make us use #10

Good point.

 

[Smart $]

Good point.

And I believe that good point is correct.