What year did the service drop over pool height change?


NEC 680.8A states service drop wires must have 22.5 clearance from swimming pool water.

Yet when I looking at graphics for service drop clearances online, I see many say 18 feet. Which implies at some point, the NEC changed the rule from 18 feet to 22.5 feet.

Does anyone know an exact year when the 22.5 rule was made?

Thank you.

Image on nachi.org showing 22.5 feet:

Image on nachi.org forum showing 18 feet:


1996 is 18 ‘, changed to 22’ in 1999 and 22.5’ in 2002.

You are awesome!

Thank you Robert.

You’re welcome, it’s always fun to flip through the old NEC books. One other tidbit, the 1975 NEC and earlier versions had no allowance for passing service drop conductors directly over a pool at any height. The 18’ allowance was added in the 1978 NEC.

That would explain why I see so many service drops over pools on houses built in the 1960’s and 70’s.

Thank you.