Rewiring American Christmas Lights

[jtaunton]

I'm off to America soon, so though I would stock up on Christmas lights as they are cheap over there.

I did the same last year and wired two sets of identical lights in series, before then plugging them into UK mains (US mains is 110V). All was fine for a bit, but then I changed them into twinkling mode and I guess that it resulted in some 230V appearing across somewhere it shouldn't and the whole lot blew.

I am still reasonably happy with the whole idea of wiring them up in series again when everything is working, but am a bit worried about what happens when something blows and something floats high, especially when outside.

I don't fancy buying new transformers for every chain of lights, as it will do away with much of the saving, but has anyone got any suggestions in this area.......

 

[Lectrician]

I run my American lights off a 3kVa site transformer.

Wired in series, mine seemed to blow bulbs for a past time!

American ones are not very weather proof either - they let water in

Also, in series, you have your 30mA RCD (THAT YOU MUST HAVE) protecting a huge amount of cable out in wet trees etc. Umm.........how often do you want to reset your trip

 

[jtaunton]

About that RCD......

 

[felix]

If by twinkling mode you mean that groups of lights flash independently then it's obvious why they blew.

Think about it. In each set you actually have many strings of bulbs in parallel. These are 110 volt strings so on the correct supply they can flash on and off as they please. Now you put two such systems in series across our 240 volt supply, which is already a bit too big. What's going to happen if all strings are on in one set but only one is on in the other? Answer - the single string gets most of the voltage and goes pop.

On top of this balance problem, the fact that twinkle mode is selectable suggests that there's some electronics in there that might not take too kindly to running on 240 volts.

The answer is of course to use an isolating, step-down transformer. This will also eliminate nuisance RCD tripping when your outside lights get damp.

 

[breezer]

The answer is of course to use an isolating, step-down transformer. This will also eliminate nuisance RCD tripping when your outside lights get damp.

or get the right product for the right job. since your lights all though will work do not comply with any UK / European regs what so ever. happy bonfire

 

[ban-all-sheds]

I run my American lights off a 3kVa site transformer.

Bet that looks nice in the corner of the living room. Do you decorate it with festive tinsel?

 

[ban-all-sheds]

or get the right product for the right job. since your lights all though will work do not comply with any UK / European regs what so ever. happy bonfire

Yup - American lights are guaranteed to be dangerous - they have such a lax attitude to safety over there, particularly product safety, and the culture and legal system is such that a manufacturer can produce any old rubbish with no fear of ever being sued for damages.