Service upgrade

[Toros]

Hi
My client wants to upgrade the existing 400A, 3 PH., 277/480V PANEL TO 600A.

the existing underground feeders to this sub panel is parallel; (2) 4" pvc s,
Each conduit contains (4) Aluminum wires plus green/EGC

Hardly read the conductor type , it says; THHN/THWN-2 250 Kmil 90c and they come
in diffrent colored jacket; brown gray, orange.....

can these wires delivers min. 600A??????

or do we have to change the wires aslso tenant main breaker ?????

Tanx

 

[don_resqcapt19]

The maximum permitted over current protective device for the existing cables is 450 amps.

 

[mwm1752]

230.31 Size and Rating
(A) General. Underground service conductors shall have sufficient ampacity to carry the current for the load as calculated in accordance with Article 220 and shall have adequate mechanical strength.

But it appears you are referring to a feeder not service a service upgrade

 

[Toros]

Hi
My client wants to upgrade the existing 400A, 3 PH., 277/480V PANEL TO 600A.

the existing underground feeders to this sub panel is parallel; (2) 4" pvc s,
Each conduit contains (4) Aluminum wires plus green/EGC

Hardly read the conductor type , it says; THHN/THWN-2 250 Kmil 90c and they come
in diffrent colored jacket; brown gray, orange.....

can these wires delivers min. 600A??????

or do we have to change the wires aslso tenant main breaker ?????

Tanx[/QUOT




can I replace this panel from 490A to 600A
while saving the existing underground cables