230.24 exceptions explanation

[jkpyke]

Hi I have a book question and I am confused on the wording for 230.24 exceptions.

My question is: A dwelling 3-wire, 120/240 volt service has trade size of 2(53) RMC mast extending up through the roof overhang, with a 4" by 12" roof slope. The roof overhang is 20". If the service drop terminates at an insulator mounted on the mast riser, the minimum clearance permitted from the roof to the conductors is:

A. 18"
B. 24"
C. 30"
D. 3'
E. 4'

I choose D. 3' because of exception 2. But I guess I am confused by exception 2,3, and 4. Which would be correct for this application?

 

[Dennis Alwon]

Exception 4 is used when the service attaches to the building not the service mast.

Exception 2 is when there is greater than 4' passing over a roof.

Exception 3 would be my guess-- A-18", since the overhang is only 20"

 

[russ]

Exception 4 is used when the service attaches to the building not the service mast.

Exception 2 is when there is greater than 4' passing over a roof.

Exception 3 would be my guess-- A-18", since the overhang is only 20"

I agree it's Exception 3.
18" above the roof.