Pool lighting: failed lights, water in the light, LED conversion and electrical safety

Electrical safety comes first

Water and electricity are a dangerous combination, and pool lights put the two side by side. Any work on a pool light, its cable, its transformer or its circuit must be done by a qualified electrician. This includes simple jobs such as changing a lamp.

The rules reflect the risk.

• Low voltage. Dubai Municipality's technical guidelines for pool plans require low voltage underwater lights, and say each electrical circuit must have an earth leakage circuit breaker shown on the drawings.
• Safety transformers. DEWA's Regulations for Electrical Installations require extra low voltage equipment such as underwater light fittings to have a double wound safety isolating transformer, built in or mounted separately, complying with BS EN 61558.
• Registered contractors. The same regulations require all electrical contractors to enrol with DEWA before carrying out installation works in Dubai.
• Abu Dhabi public pools. The municipality's pool guide requires lighting and other circuits around the pool to be grounded under the electrical wiring regulations, each circuit to have an earth leakage circuit breaker, and all defects in underwater lights and their lenses to be repaired.

Manufacturers say the same. Pentair's installation guide for its IntelliBrite LED pool light warns that line voltage models can shock, burn or kill, says power must be disconnected at the circuit breaker before the light is serviced, and requires installation by a licensed or certified electrician or a qualified pool professional.

Why a pool light stops working

The common causes are:

• A tripped earth leakage device. Pentair's troubleshooting table starts with checking the ground fault protection and resetting it. If it trips again, there is a fault. Do not keep resetting it, and call an electrician.
• A failed lamp or LED module. Lamps and LED boards reach the end of their life.
• A wiring or junction box fault. Pentair also points to the connection at the junction box and the power supply to the light.
• A failed transformer on low voltage systems.
• Water inside the fitting, which can damage the light and create a hazard.

An electrician can work through these with test equipment. Guessing, or swapping parts at random, is how dangerous faults get missed.

Water in the light

Moisture or water behind the lens means the seal has failed. Pentair's guide says a new lens gasket must be fitted every time the light is taken apart, and warns that if it is not, water can leak into the assembly, creating a risk of electric shock or a broken lens.

If you see water in a light:

1. Switch the light off at the breaker and leave it off.
2. Keep swimmers away until an electrician has inspected it.
3. Do not try to open the fitting yourself.
4. Tell whoever looks after the pool, so the light is not switched back on by mistake.

How a wet niche light is serviced

Most pool lights sit in a niche, a housing set into the pool wall. Pentair's guide describes a length of spare cable coiled in the niche (about four feet in its instructions) so the light can be lifted out onto the deck for service without draining the pool. It also says lights must never be replaced by splicing cable under water or behind the niche, and that the special pilot screw holding the light also earths the housing to the niche, so it must always be refitted.

Pentair's guide also says the pool should be filled until the light is fully submerged before the light is operated for more than ten seconds. Do not run underwater lights while the pool is drained for work.

LED conversion

Many older pool lights use incandescent or halogen lamps. The US Department of Energy says LEDs use up to 90 percent less energy and last up to 25 times longer than incandescent bulbs, which is the main reason owners convert. Fewer lamp changes also mean fewer times the fitting has to be opened.

A conversion is still electrical work, and a few points need checking:

• Compatibility with the niche. Pentair states its LED light must only be used in its own niches to keep its safety listing and warranty. Other brands set similar conditions.
• Voltage. The new light must match the supply, and low voltage lights need a suitable safety transformer.
• Cable length and condition. There must be enough sound cable to reach the junction box without splicing in the wrong place.
• Lighting levels. Dubai Municipality requires pool lighting to light the whole pool, including the floor, without glare, reflections or risk of shocks, and limits general lighting intensity to 50 lux. Abu Dhabi's public pool guide sets the same limit.
• Controls. Colour changing LEDs may need a compatible switch or controller.

What to ask the electrician

• Is the circuit protected by a working earth leakage device, and when was it last tested?
• Is the light low voltage, and is the transformer suitable and correctly located?
• Is the light compatible with the existing niche, or does the niche need work?
• Will a new gasket be fitted, and will the light be tested under water before you leave?

A working, sealed, properly protected light is a safety feature as well as a pleasure. Treat any fault with it as an electrical job first and a pool job second.