My pool light looks as below, 220V AC to 12V AC, with a 12V LED light bulb submerged in a water tight enclosure. 

Any electric leak on the 12V side would not be detected on the 220V side of the transformer, right?

Is it possible and even a good idea to have a ELCB breaker on the 12 AC side?

 

Correct, a leak on the 12V side wouldn't be reflected across the transformer.

 

It's certainly possible, whether such a device actually exists is another thing altogether.

 

A leak on the LV side isn't going to present a hazard to the occupants of the pool (the 12V isn't ground referenced anyway) and probably won't upset the lighting either unless a unit is full of water in which case you'd probably notice.

 

Any specific worry??

 

 

 

5 minutes ago, Crossy said:

Correct, a leak on the 12V side wouldn't be reflected across the transformer.

 

It's certainly possible, whether such a device actually exists is another thing altogether.

 

A leak on the LV side isn't going to present a hazard to the occupants of the pool (the 12V isn't ground referenced anyway) and probably won't upset the lighting either unless a unit is full of water in which case you'd probably notice.

 

Any specific worry??

 

 

 

The worry is electrocution, I am on murder island after all.

What is this about not being ground referenced, does that make the 12V AC safe, even is saline or ionized chlorine water?

Maybe I am over thinking the ELCB idea a bit, just want to be way on the safe side.

The 12V isolated isn't going to kill anyone, any fault likely to cause issues to the pool occupants (transformer failure) would be detected by the RCD on the 220V side.

10 minutes ago, Crossy said:

The 12V isolated isn't going to kill anyone, any fault likely to cause issues to the pool occupants (transformer failure) would be detected by the RCD on the 220V side.

OK, no worries then. The transformer is a brand name and in good condition. 

What got me a bit nervous was that the old light housing, which have probably not been serviced for years, was waterlogged and the LED bulp was done for.

 

 

Pool light have been restored and we are all still alive.

The 12V ELCB idea is in the bin. Not the only wacky idea in there. That is the price to pay when you are Jack of all trades, but master of none.

 

As Crossy highlights, the 220 - 12 volt transformer is effectively giving the galvanic isolation (with the caveat the transformer must be rated for such a deployment. Also, if the wires come loose on the 220 volt side and drop onto the 12 volt side, this is clearly hugely dangerous and you should NOT be surprised if that risk is present). I agonised for a long time on the way forward when I renovated our commercial pool. In the end I went for 12 Volt DC LED luminaires and used Meanwell AC/DC constant voltage PSUs. . . I also used a 3-phase Siemens RCD (costly!!!) on the incomer to give additional safety and generally improve the standard of the the pump room (pumps are 3-phase). . .

 

What'll really get your head in a twist is the topic of equipotential bonding and wet zones around a pool. All the rebar in the pool is supposed to be bonded to the hand rails, metal window frames, everything. It's a huge topic.

 

 

 

 

... needs a clean though. Doesn't get much use thanks to covid...

 

 

6 hours ago, Led Lolly Yellow Lolly said:

... needs a clean though. Doesn't get much use thanks to covid...

 

 

Did you opt for warm white or daylight for your pool light?

Is there a preference?

I went with warm white because I prefer to keep the feel of the old halogen lights.