EE_Intern_2
Member
Hi,
I have a design question.
I have 225A 120/208V 4 Wire feeders going to a panel via a 50 foot (one way) undeground run.
after the 50 foot run the cables come up to a disconnect switch and are exposed to high ambient temperatures before they go into a building and feed the panel.
If only a short section of cable, say less than 5 feet, are exposed to the high ambient temperatures, do I have to derate the cables for the ambient temperatures for this small section, or can I ignore derating for the ambient temperatures?
I understand since this is a 120/208 4 wire system, that I must also derate the cables for 4 current carrying conductors.
Thank You
I have a design question.
I have 225A 120/208V 4 Wire feeders going to a panel via a 50 foot (one way) undeground run.
after the 50 foot run the cables come up to a disconnect switch and are exposed to high ambient temperatures before they go into a building and feed the panel.
If only a short section of cable, say less than 5 feet, are exposed to the high ambient temperatures, do I have to derate the cables for the ambient temperatures for this small section, or can I ignore derating for the ambient temperatures?
I understand since this is a 120/208 4 wire system, that I must also derate the cables for 4 current carrying conductors.
Thank You