SIRSPARKSALOT
Member
- Location
- Northern NJ
Just checking myself. I do not do 400A residential services. I have a 400A residential 120/240 1-phase service to do.
Transformer to 320 Meter Socket
(6)#3/0 CU (1) #3 in 3" PVC conduit underground from the transformer to the 320 meter socket
(6*0.3117)+(1*0.1134)=1.9836 in2
3" PVC=7.268in2 @ 40% =2.9072 useable conduit area
*Conduit correctly sized for wires
310.16 says #3/0 is good for 225A at 90C (derating off 90C if less than 75C terminations)
310.15(B)(2)(A) says 4-6 current carrying conductors derate 80%
Therefore 225A*.80=180A per phase conductor *2=360A
240.4(B) allows the next higher fuse size being 400A
Any help is appreciated. I want to make sure I have this correct in my head before proceeding.
Thanks!
Transformer to 320 Meter Socket
(6)#3/0 CU (1) #3 in 3" PVC conduit underground from the transformer to the 320 meter socket
(6*0.3117)+(1*0.1134)=1.9836 in2
3" PVC=7.268in2 @ 40% =2.9072 useable conduit area
*Conduit correctly sized for wires
310.16 says #3/0 is good for 225A at 90C (derating off 90C if less than 75C terminations)
310.15(B)(2)(A) says 4-6 current carrying conductors derate 80%
Therefore 225A*.80=180A per phase conductor *2=360A
240.4(B) allows the next higher fuse size being 400A
Any help is appreciated. I want to make sure I have this correct in my head before proceeding.
Thanks!