RME INC
Member
- Location
- Santa Rosa, CA.
I have a 30 plus year old building with a 400 amp 120/240 volt delta power system. With old cloth style 3/0 or 4/0 aluminum wire that the insulation is coming off at the weather head.
I need to replace the conductor from the weather head to the panel.
Existing conductor is in 3" conduit approx. 45'.
There are two hots and one neutral with the larger size conductors and the center buss has a smaller size conductor.
Conductor comes in at the top of the panel to the buss bars then goes to the meter then to the main breaker.
I am having trouble determining the size conductors I need for this application.
I refer to table 310.15b and looks like size 500 THHN copper.
Need assistance Help.
Question: Why were the old conductors sized smaller and the smaller stinger leg conductor?
I need to replace the conductor from the weather head to the panel.
Existing conductor is in 3" conduit approx. 45'.
There are two hots and one neutral with the larger size conductors and the center buss has a smaller size conductor.
Conductor comes in at the top of the panel to the buss bars then goes to the meter then to the main breaker.
I am having trouble determining the size conductors I need for this application.
I refer to table 310.15b and looks like size 500 THHN copper.
Need assistance Help.
Question: Why were the old conductors sized smaller and the smaller stinger leg conductor?