National Electrical Code Tips: Article 680 -- Swimming Pools, Fountains, and Similar Installations
Humans have enjoyed swimming pools for thousands of years, but they haven't
always installed electric lights in them or circulated the water with pumps.
Adding those and other electric features makes pools potentially lethal, and the
requirements of Article 680 protect against such an outcome. This article covers
similar installations, such as spas and hot tubs, too.
Similarly, we enjoy fountains in our cities and parks. We probably wouldn't
enjoy being shocked by them. And again, Article 680 provides requirements that
The main job Article 680 tries to do is keep electricity and water separated,
so that when people are in the water or in contact with related equipment, they
are also separated from electricity.
- If you install any type of pool, tub, or fountain and supply it with
lighting, pumps, or similar equipment, the installation must conform to Article 680 [680.1].
- You'll read in 680.6 that equipment must be grounded per Parts V, VI, and
VII of Article 250. Unfortunately, this requirement is incorrect. Part V of
Article 250 is about bonding, not grounding. Generally, you do not ground
load-side equipment. You bond it. Because of incorrect wording throughout the
NEC, you'll need to read the Article 100 definitions of bonding and grounding,
and then apply some common sense to interpret which one a particular requirement
- Overhead clearances can be a bit confusing with regard to pools.
Fortunately, the NEC now provides a means of determining clearances without
pulling your hair and gnashing your teeth. See Table 680.8 and Figure 680.8.
- For minimum cover depths, see Table 680.10. Generally, you must bury
metallic raceways at least 6 inches deep and nonmetallic at least 18 inches
deep. If you have a good trenching tool, consider going deeper. The added
protection can't hurt. Be sure you contact the local utility companies for a
survey (typically, that means calling 811) and properly map out the route before
trenching. Remember, you can dial 811 now or 911 later.
- The requirements for permanently installed pools are in Part II. Key
concept: The branch circuits are permanently run in raceway and everything must
be bonded back to the service through a "grounding" conductor run in the raceway
with the current-carrying conductors.
- The requirements for storable pools are in Part III. Key concept:
Cord-connected pumps, which are typical of these installations, must be
- The requirements for spas and hot tubs are in Part IV. Key concept: You must
provide an emergency switch. This is a special kind of switch, and the on/off
switch at the control system does not meet the requirement. Also, you can bond
through a common equipment frame. But from an engineering standpoint, that
should be an additional bonding path. It's best to run bonding conductors from
point to point. You can't really overbond, but you can have problems if a
bonding connection fails.
- The requirements for fountains are in Part V. Key concept: All equipment
must be removable for servicing, without lowering the water level. So, for
example, you can't embed a light into the fountain structure below the water
- The requirements for therapeutic pools and tubs are in Part VI. Key concept:
You must bond certain things together [680.62(b)]. What you should do is bond
everything metallic. This list of five items probably covers everything, but if
you make a point of bonding everything metallic then you have certainty and not
mere probability. Remember, bonding eliminates dangerous differences of
- The requirements for hydromassage tubs are in Part VII. Key concept: Such
tubs and their associated equipment must be on an individual branch circuit and
protected by a readily available ground-fault circuit interrupter.