Re: swimming pool
Just another note about the importance of bonding from an actual case history:
Several swimmers were electocuted in a pool; investigation discovered that the source of the current was wiring located at the top of the stone wall enclosing the pool area. A light fixture was apparently disconnected many years prior to the incident, but the wiring was left energized. Grounds maintenance had recently watered shrubs planted between the wall and pool area, inadvertantly soaking the wiring box (which was not visible from ground level), the stone wall,shrubs, and grass border. The wet surfaces created a sufficient current path from the energized wiring through the pool. The pool was probably constructed before bonding requirements were written; the tragedy would have occured even if the branches feeding the pool equipment were installed according to today?s requirements.
Bonding would have provided a low impedance path for the current and would have eliminated the possibility of voltage gradients through the pool water and surrounding surfaces. Obviously, code today would have required either greater separation of the light from the pool or bonding of the light to the pool system and GFCI branch circuit protection. When a pool is added to a location previously used as ordinary outdoor space, we have to reconsider all electrical elements in its vicinity as potential sources of hazardous current and bring them into compliance, too.