Clearance requirements for pool installations near overhead and underground wiring

By Tatjana Dinic

Electrical safety around swimming pools is critical. Overhead power lines as well as underground wiring represent a shock hazard when in close proximity to swimming pools.

The Canadian Electrical Code (CEC) has specific requirements in Section 68, Pools, tubs, and spas, intended to provide enhanced electric-shock protection in these aquatic environments by means of bonding and ground fault circuit interrupter (GFCI) protection.

In the December 2013 issue of Pool & Spa Marketing, pool bonding and GFCI protection were discussed as a means of providing protection to people. This article will focus on clearance requirements between pools and overhead power lines and underground wiring as another means of achieving a safe swimming pool installation environment.

Keep in mind the rules in Section 68 of the CEC regarding clearance requirements between swimming pools and overhead power lines or underground wiring are applicable to wires owned by consumers or local distribution companies (LDCs).

Before reviewing clearance requirements, however, it is important to note Rule 68-002 of the CEC defines a pool as permanently installed and storable swimming pools; hydromassage bathtubs; spas and hot tubs; wading pools; baptismal pools; decorative pools; and splash pads. Therefore, all clearance requirements for overhead or underground wiring are also applicable to hot tubs and splash pads.

Overhead wiring

Clearance requirements between pools and overhead power lines are required to minimize the possibility that a person in or near the swimming pool might come into contact with overhead conductors.

Overhead power lines may not have an insulated covering; this means any conductive object (i.e., pool skimmer or ladder) which makes contact with these lines will become energized and can cause lethal electrical shocks to the person coming in contact with them. For instance, skimmers are often used for pool maintenance and are typically mounted on a long, aluminum handle and can be easily lifted into the air. If the clearance between the pool and any overhead power lines is insufficient, contact between the skimmer’s handle and power lines could be deadly to the user (e.g. a 3-m handle plus the height of the person using the equipment).

Primary distribution and transmission power lines (above 750 V) are typically non-insulated, bare conductors and carry high-voltage power. Secondary distribution power lines (below 750 V) may be insulated and carry low-voltage power. However, the insulation of these conductors may deteriorate over time due to harsh environmental conditions, such as snow, ice, and scorching heat. As a result, the conductors may become frayed or have cracked insulation. Further, some secondary distribution power lines only contain a weather covering, which does not have any insulating value; therefore, it is always the safest assumption to consider all power lines as non-insulated.

Best case scenario

Ideally, there should be no wiring above a pool or the surrounding deck. In fact, CEC Rule 68-054 prevents pools from being located under overhead wiring. However, locating a pool below overhead conductors is sometimes unavoidable. For example, on a building lot with limited area or a lot where the overhead lines are already in place.

In these circumstances, Rule 68-054 provides some specific exemptions to the type of wiring that are permitted to be located over a pool provided that certain clearances have been met and are maintained. This rule requires the following:

• Communication antenna distribution conductors and power lines (neutral supported cable type) 750 V and below are permitted above the pool and elevated surfaces associated with the pool, or above the adjacent area, provided there is a clearance of at least 5 m (16.4 ft) measured from the outer edge of the pool or from other elevated surfaces associated with the pool.
• All other power lines, operating at not more than 50 kV, are permitted above the pool and elevated surfaces associated with the pool, or above the adjacent area, provided there is a clearance of at least 7.5 m (24.6 ft) measured from the outer edge of the pool or from other elevated surfaces associated with the pool.

The specified clearance requirements stated above are applicable to the pool and other associated elevated surfaces, such as a diving structure, slide, swings, observation stand, tower, or platform, or above the adjacent area extending 5 m (16.4 ft) horizontally from the pool edge.

Figure 1 (above), located in the Appendix B note of Rule 68-054, illustrates the minimum clearances for conductors over swimming pools. No conductors would be permitted under any circumstances in the area under Line 1. In the area above Line 1, insulated communication conductors and neutral supported cables operating at 750 V or less are permitted. Any other conductors operating at not more than 50 kV are permitted above the area outlined by Line 2. Clearances shown beyond 5 m (16.4 ft) from the pool edge are found in Rule 12-304 and Table 34.

When considering code requirements, it is important to factor in clearance not only for the pool, but also for any adjacent area or structure, e.g. sheds, decks or fences extending 5 m (16.4 ft) horizontally from the pool edge. In the picture here, the clearance requirements specified by Rule 68-054 are not satisfied. The conductors are within 5 m (16.4 ft) from the pool and the clearance from the wires to the edge of the pool is less than 5 m (16.4 ft).

It is important to understand the clearance requirements specified in Rule 68-054 are harmonized with Canadian Standards Association (CSA) standard C22.3 No. 1, Overhead systems. Many LDCs reference this standard as part of their electrical safety distribution regulation.