Learning how to wire up your pool lights is an important step.
If you get this wrong, your lights won’t work. In addition, they can create a severe hazard – damaging your lights and potentially risking electrocution.
There are a lot of steps involved in installing the lights in place, but you also need to consider how to connect them to the power – and whether they need a transformer.
Some pool lights don’t need a transformer and are designed to run on mains voltage, but many are now low voltage lights and so will need a suitable transformer to step the power down from 120V to the 12-14V required.
There are a few things here worth diving into in more detail, so let’s take a look at:
- Whether all pool lights need a transformer
- If it’s possible to use any landscape transformer for pool lights
- Where a transformer should be placed
Do All Pool Lights Need A Transformer?
Let’s be absolutely clear from the start – not every pool light will need a transformer.
Let’s quickly look at what a transformer does and when it would be needed.
A transformer is an electrical device that throttles the voltage on a circuit.
It’s designed to be plugged into a mains circuit – either hardwired or in a suitable outlet.
Then it steps the voltage down so that the rest of the circuit has the power it needs but at a much lower voltage.
Mains voltage in the US is 120 volts.
If you live elsewhere, it may be higher – in the UK and Europe, it’s 230 volts, for example.
That voltage is necessary to power many of the devices we use around the home, but not all of them – especially not some modern lights, which can work perfectly well on a low voltage, typically 12-14 volts.
A lower voltage doesn’t save you money – you pay for watts, not voltage – but it is much safer.
Safety is a crucial consideration when dealing with pool lights and, therefore, a potential mix of water and electricity.
However, not every pool light is a low voltage one. Many older lights, and some contemporary lights, are still designed for mains voltage.
Remember that it’s not the transformer that makes your pool safer.
This does the job of stepping the voltage down, yes. But it’s choosing low voltage lights which are safer.
A transformer isn’t nice to have. It is essential, but only with low-voltage lights:
- Pool lights designed for mains voltage, without transformer will work fine.
- Pool lights designed for mains voltage with transformer, won’t work properly because they don’t get sufficient power
- Low voltage lights with a transformer, will work fine.
- Low voltage lights without transformer, will be massively overloaded. They’ll burn out, and probably be a safety hazard.
If you use low-voltage lights, note that one transformer is all you need if you have them wired into the same circuit.
You don’t need a transformer for every single light.
But be aware that if you’re using a timer, that would mean all lights will be on the same timer.
That’s probably what you want to happen. If you did want different lights to come on at different times, you’d need separate circuits, each with its own transformer.
Can I Use A Landscape Transformer For A Pool Light?
Transformers aren’t just used for pool lights. They have other uses too.
Typically they’ll be built into the plug or power cable of a device, but a standard transformer you might have to install yourself is one for landscape lighting.
If you have a garden with lighting, chances are it’s low voltage – the most common lights for outdoor use are.
So you might already have a landscape lighting transformer.
Can you use that for your pool lights as well? If you don’t already own one, will any outdoor transformer do?
The answer to both is no. Pool lighting transformers will state that they are suitable for pool or spa lighting, and you have to use one of these for any submerged lights.
That’s not just a recommendation. Article 680.23 of the National Electrical Code states that:
“Transformers and power supplies used for the supply of underwater luminaires, together with the transformer or power supply enclosure, shall be listed, labeled, and identified for swimming pool and spa use.”
Landscape lighting transformers are not completely waterproof – they don’t need to be.
They’ll be shielded by a box, but they’re often left open at the bottom.
As long as they’re installed a sufficient distance from the ground, you will not have problems with water affecting it just from the rain.
However, with a pool, nearby splashes become much more of a risk. So pool transformers tend to be fully enclosed and better protected.
In theory, you could use one pool light transformer for pool and landscape lights, but you’ll need to make sure you don’t overload the transformer.
Having them on separate circuits with separate transformers might make more sense.
Where To Place A Pool Light Transformer?
A transformer needs to be placed between the circuit breaker/power outlet, and the junction box where the lights are wired to.
You’ll want to ensure it’s mounted at least a foot from the ground, with the wiring compartment facing downwards.
It needs to be at least 4 feet from the nearest edge of the pool.
But if you can wire it as close to the junction box, provided you meet these minimum requirements, that would minimize any risk of voltage drop from the transformer to the pool lights.
Final Words
Only some pool lights need a transformer – it depends on the voltage that the light is designed for.
This is important – using a transformer when it’s not needed will stop your lights from working, but not using one when it’s needed will destroy your lights and could even make your pool an electrocution risk.
Most modern pool lights sold, mainly LEDs, will be low voltage due to their increased safety, so you’ll typically need a transformer.
But check your lights if you aren’t sure – the voltage will be detailed on the back of the light.
Have you got low voltage lights or mains voltage lights for your pool? Are you considering updating your lights to low-voltage ones and adding a transformer?