cable vs OCPD

[rayertz]

Can I use 2 sets of 350's to feed a process control panel?

Please see attached sketch.

 

[Pharon]

Assuming terminations are rated 75 degrees C, I'm pretty sure you need to use 400's to comply with 240.4(B). Or change out that 700A CB and replace with a 600A.

 

[rayertz]

I want to use the 350's to the control panel main. I am thinking I can use the OCPD in the control panel to protect the cables upstream.The breaker in the PDP would merely be a switch.

 

[infinity]

If you keep the 700 amp OCPD then your parallel 350's would be tap conductors and the tap rules would apply.

 

[petersonra]

(2) 350s is 620A. The next std size OCPD rating is 700A.

why can't he use it

 

[infinity]

(2) 350s is 620A. The next std size OCPD rating is 700A.

Good point.

 

[rayertz]

Thanks for your help.

I got it worked out with the plant. The original design was to use a 600 amp breaker. If we use a 100% rated breaker they said no problem. So the 700 amp breaker goes away.

Thanks again...