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Changing led driver

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Pro
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Changing led driver

I have a cheapie 10w Chinese led light which has a 230v supply. I want to use it in a "moist" environment, so am looking to drop the supply voltage. It should be as simple as just changing the driver for a 12v input one shouldn't it?

 

20190302_154216.jpg

Current driverCurrent driverPotential driverPotential driver

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Hero
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Re: Changing led driver

I have never come across one of these that's not outdoor rated. I use two outside my property, both connected to the 240V mains.

However now you've got it apart and if there's a possibility you can't seal it again properly, why not strip out the waterproof (thats what IP67 means) power supply that's built in and use that back at the mains supply, just extend the 12V cabling until you are in the dry. However you will need to put the power supply in an insulated box as the supply wires need more insulation to meet safety standards. If you want to run it off a fixed 12V dc supply then you do not need a power supply. Just make sure you keep the polarity correct.

Using a transformer to get from 240V ac to 12V ac then a 12V ac to 12V dc power supply makes no sense.

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Champion
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Re: Changing led driver

The existing PSU and the one you're looking at are the same..!

Both input mains voltage, from 90vac to 260vac, both outputs 12vdc

As you're opting for a moist location, you could always put the existing PSU into a weather proof box, extend the red and black (doesn't need to be that colour, any would do as long as they're identified - red & black sleeves or electricians tape) wires and connect them back into the LED fixture. This 'extension' wiring would need to be the same thickness or indeed slightly bigger for a longish run.

The cable from the new box to the LED light would be safe as it'll only have 12 volts running through it - near a pond etc.

A crude drawing might help:

i've done it.PNG

I've done the above before, but long runs of cable will cause the voltage to drop, which if it's too long could cause the LED to act up.

If you're not competent, don't do this, it's up to you and it's only a suggestion to solve your issue Wink

 

edit. lol, took too long to draw piccy as reply above wan't there when I started!!

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Re: Changing led driver

Extending the 12v cables has been on my mind (thanks both for the suggestion), I just thought it would be easier and cleaner replace the driver. These lights aren't particularly safe anyway, with the 230v supply as they don't supply an earth, and it if they do it isn't terminated! This is why I wanted to drop the voltage. By a moist environment, it is going in the sump area of my marine aquarium to grow algae. This in itself isn't so much a problem, it is the salt creep that will potentially cause issues, thus trying to make it as safe as possible. I would need to extend the cable by potentially 3 feet, so not sure how much voltage drop would be involved in that?

One last question, would a plastic box be sufficient for the driver as they produce heat and potentially melt? It is currently mounted in a metal casing (not attached using paste though, so probably not good for heat dissipation).

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Anonymous
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Re: Changing led driver

I don't want to poo poo your idea but remember there are regulations that might / must comply with. You don't want to infringe any regulations that might render your home insurance null and void.

This link may be of use to you @Marksfish http://wiki.diyfaq.org.uk/index.php/Taking_electricity_outside

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Champion
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Re: Changing led driver

Without going all geeky

Google double insulated Wink

These lights aren't particularly safe anyway

Depends how much dosh you want to spend - from experience, cheap Chinese is just that .... it might work for a few months, or if you're really lucky they can last many years....

Regarding safety, they should comply with regs, but it doesn't mean they do.

they don't supply an earth

again, double insulated - same for UK kettles (as an example), metal enclosure with no earths.

Also, back in the day houses were supplied with live, neutral and a separate earth (used outer armouring) - nowadays the neutral and earth are combined. edit at the home, not the substation (the earth was always connected at the substation anyway). They (as in those that run your local network, use one large live and multiple neutrals, that are bunched together, the earth from our home is then terminated in the same connection as the neutral)

You can use 3 core cabling from the mains throughout your setup, connecting an earth into (my badly drawn) first 'box' and then 3 core to the LED - but at 12vdc, it doesn't need it.

I would need to extend the cable by potentially 3 feet, so not sure how much voltage drop would be involved in that?

That's fine, I was thinking many metres - but do a dry run first (lay it all out and check before fitting it permanently)

would a plastic box be sufficient for the driver as they produce heat and potentially melt?

It did look plastic - valid point - go for a metal box rated for the environment it's going in, but then I'd wire 3 core (L, N and earth) to the 'first' box for sure (belt and braces).

Another thought is to space the driver off from the base of the plastic box - I've got no way of knowing how hot the driver gets as there could well be slight variances in build quality etc.

 

 

Valid advice from mook too.

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Hero
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Re: Changing led driver

Salt around a light in an aluminium enclosure is not a good idea. With respect to the cable length, three feet is insignificant from a resistance point of view say 1mm sq core cable will do. 

@Anonymous If only 12V is being taken outside then there is no outdoor mains wiring.

Of more concern is the power supply. This needs to go in a metal box, for example, https://www.ebay.co.uk/itm/Diecast-Aluminium-Stompbox-Enclosure-Box-1590B-1590BB-1590XX-New-/323585032363. If the salty water gets inside the lamp then there is likely to develop a short circuit on the power supply. Depending on the design, the power supply could get very hot under these conditions so needs to be located on a fireproof surface or wall. You also need to properly gland the mains cable with a fire resistant gland

Unless you know what you are doing you should not do this.

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Re: Changing led driver


@Anonymous wrote:

This link may be of use to you @Marksfish http://wiki.diyfaq.org.uk/index.php/Taking_electricity_outside


But it isn't going outside..

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Re: Changing led driver


@DS wrote:

Without going all geeky

Google double insulated Wink


Yep I know double insulated from my PAT course.

These lights however are not. Some come with 2 core cable too thin and some come with three core cable with earth not terminated. There is no class 2 symbol on them, so by regs they should be treated as class 1 and earthed.

This is a get by until proper lighting can be manufactured to my specifications. It is a lot safer than the cfl bulbs and lamp holders that used to be used a few years ago Smiley

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Re: Changing led driver


@Baldrick1 wrote:

Salt around a light in an aluminium enclosure is not a good idea. With respect to the cable length, three feet is insignificant from a resistance point of view say 1mm sq core cable will do. 


 

No I agree. It is a temporary measure while the lights I need are being manufactured. As well as the corrosion, there is the possibility of contamination of the water and damage to my fish/ corals. Of course, if not done correctly, some risk to me too Wink

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Re: Changing led driver

Some come with 2 core cable too thin and some come with three core cable with earth not terminated. There is no class 2 symbol on them, so by regs they should be treated as class 1 and earthed.

IF you were to decide to earth the LED light itself, although I think I pointed it out above...?, you'd need to check that the LED strip isn't touching the casing.

It's not uncommon to find a very flimsy piece of plastic that goes between the rear of the LED strip and the casing. Some crudely built lights can have sharp solder tips that puncture the insulator.

It does sound like you know about things electrickery related, but checking everything is important.

 

As the saying goes, if you see me dancing without music playing, hit me with a wooden brush.....

(as I'd probably be getting an electric shock! - been there (and caused by muppets) and it ain't pleasant)

(Oh, and volts jolt, current kills!)

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Re: Changing led driver


@DS wrote:

 

As the saying goes, if you see me dancing without music playing, hit me with a wooden brush.....

(as I'd probably be getting an electric shock! - been there (and caused by muppets) and it ain't pleasant)

(Oh, and volts jolt, current kills!)


Had a cooker related incident myself a few years ago now (30 odd), yes, I did dance for a few days afterwards. I was lucky and learned a lot from that experience! Working with packaging machinery now and every day I come across incompetent wiring from professional "electricians". Makes every day exciting Smiley

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Re: Changing led driver


@DS wrote:

IF you were to decide to earth the LED light itself, although I think I pointed it out above...?, you'd need to check that the LED strip isn't touching the casing.

Providing the power supply has an isolating transformer, which I would expect, this is not an issue.

As the saying goes, if you see me dancing without music playing, hit me with a wooden brush.....

I'm very keen on RCDs, which are an essential requirement for any application where the wet can get in. Older houses won't have them unless the consumer unit has been changed or the plug in type is used. I have also run an external earth to the casing of the ones that I have installed. If there is any leakage the RCD should do its stuff.

(Oh, and volts jolt, current kills!)

The mantra I was taught is "It's the volts that jolts but the mils (as in milliamps) that kills". I have also been on the receiving end of more than my fair share in the early days before the Elfin Safety brigade set the rules regarding live working. 


 

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Re: Changing led driver

Had a cooker related incident

Some that spring to mind....

1kv from megger tester

2.5kv from above

4kv, yes 4, from flash tester

240 from various sources

415vac from a gen set - can't remember output but it was roughly the length of a dd bus!

Providing the power supply has an isolating transformer, which I would expect, this is not an issue.

Totally agree, but as I've alluded too, Chinese..... Wink

I'm very keen on RCDs

Oddly, I initially wasn't, well indoors here at DS HQ anyway .... didn't like them. The then setup, fuse wire, was 'better' (not safer) as when it blew, you're renewing it, rather than resetting it. As (what appears US sparks know) RCD's lose a bit of their capacity during tripping incidents - the amount of nuisance tripping callouts I'd sort out was quite astonishing imho.

I was/am a qualified electrical and mechanical engineer - starting as a panel wireman / fitter man. Went on to be a service tech (including breakdowns) for the switchgear industry. Downgraded to domestic for a while (17th edition) but it's all the same;)

I can put one of many claims to fame - I, not my fault mind you, was involved with knocking American Express UK offline. I did warn them but the maintenance lad told them I'd fixed it, when in fact I'd not even started!! When it went 'click', you should have seen his face!!

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Re: Changing led driver


@Baldrick1 wrote:

Salt around a light in an aluminium enclosure is not a good idea.

If the salty water gets inside the lamp then there is likely to develop a short circuit on the power supply. Depending on the design, the power supply could get very hot under these conditions so needs to be located on a fireproof surface or wall. You also need to properly gland the mains cable with a fire resistant gland

Unless you know what you are doing you should not do this.


Couldn't agree more with the last statement.  Salt is hardly going to be a problem. Yes, maybe in 10 years time when you want to undo screws etc but sort term, hardly.

 

The lamp / fitting  in question is rated for outdoor use i.e. IP67,.. Will withstand being under water for 30 minutes at a depth of up to 1 metre if I remember right. Salt water is hardly going to get into the fitting if the fitting is properly terminated i.e. the stuffing gland is done up tight etc.

 

@Marksfish  Much as I hate to say it, you seem to be making a mountain out of a molehill. I really cannot understand why you don't just run 230v to it. Always assuming it is going to be properly installed and not left dangling. It is designed for 230v and is CE marked and will handle a moist environment without any problems. The only difference between this light fitting and say a pump, is the IP rating. Submersibles will be IP68 minimum. 

 

Quite obviously, any mod you do to the fitting invalidates the CE mark. Whether your house wiring complies with regards type of supply, type of RCD's fitted etc, only you know that. As to the earth connection, looking at picture 2, I'd assume that is what the chrome plated screw is for.

Ever helpful. Grin Sure, I’d love to help you out. Now which way did you come in?