LED drivers...

[EllieP]

Greetings my little Sparky-type peeps,

8 x LED lights in ceiling, wired via driver for each LED into JB (2 x LEDs per JB), JBs daisy-chained back to supply. Cables from JBs all good and secure. Fine so far I think....

But what about the skinny cables from the JB to the driver and from there to the LED? SHould they be housed in plastic boxes/pattresses or something, or are they OK just clipped to the roof trusses? Just thinking they're a bit small and fragile and might need some protection?

These is the LEDs BTW, should also show a piccie of a dinky little driver... http://www.thelightingsuperstore.co.uk/product.asp?productid=41915&pt=2


Ta muchly....

 

[bernardgreen]

I would answer but at five foot ten tall I am not little.

 

[EllieP]

But of course, how remiss of me....

Let me re-phrase....

"Greetings my little and tall Sparky-type peeps,"

 

[bernardgreen]

Sorry. I do not belong to you.

 

[EllieP]

Hmmph!

OK - we'll try again...

"Greetings to all you wonderful, clever, intelligent, highly skilled and prfessional electricians,"

NOW can I have an answer or two? Please?

 

[mikhailfaradayski]

can you post a photo of the skinny cables in question?

 

[EllieP]

Piccie here...

http://www.thelightingsuperstore.co.uk/product.asp?productid=42612

Driver is approx 30mm x 25mm. Each pair of cables is approx. 500mm long.

 

[stillp]

Why do you think these cables might need protection? If theyre not likely to be disturbed during service they'll be OK clipped to the rafters.

 

[bernardgreen]

The label is a bit confusing as it seems to say output ( SEC ) is 700mA constant current 0.5 to 4 volts and then ( not clear to read ) Constant voltage 6volts <650mA

Either way there is probably no safety hazard from electric shock from the leads to the LED lamps while the "transformer" ( it is actually a switched mode power supply ) is working normally.

So no protection is needed. Using insulated clips to keep them tidy is OK. As there is good chance you will be changing them I would use cable clips for 2.5mm cable which will allow you to thread new leads in without having to pull the clip out of the timber.

The small size of the unit worries me a bit about how warm / hot it gets when in use and how it will act internally when it fails. In theory and by regulations it should fail in a safe way, ie no mains on the ouput leads not matter what happens inside.

 

[EllieP]

So no protection is needed. Using insulated clips to keep them tidy is OK.

Thanks! Will do... I'll make sure the drivers are above the loft insulation, just in case they do tend to run a tad warm....

As there is good chance you will be changing them I would use cable clips for 2.5mm cable which will allow you to thread new leads in without having to pull the clip out of the timber.

Good thinking Batman!

The small size of the unit worries me a bit about how warm / hot it gets when in use and how it will act internally when it fails. In theory and by regulations it should fail in a safe way, ie no mains on the ouput leads not matter what happens inside.

FAILS! Why would this be? Pure and simple old age and over-use or could there be a more scary reason?

 

[EllieP]

This is the planned circuit taking into account new extractor (same location, just updating fan unit) and the 8 x LEDs. It was all previously wired through the existing FC, but there are just too many wires to stuff back in the box! (Being a stud wall with a plastic back box if I push the wires too hard the box is likely to break out through the other layer of plasterboard!)

Does this drawing look OK? View media item 30522

 

[bernardgreen]

FAILS! Why would this be? Pure and simple old age and over-use or could there be a more scary reason?

Forty years ago when I started my career ( yes I am old ) equipment was designed by engineers to last. Now the marketing people prefer short life times to increase sales and designers tend to have to comply.

Old age for equipment was once 20 or even 40 years. Now a lot of low cost equipment is ancient by the time it reaches its second birthday if it lives that long.

Bernard ( old and often grumpy )

 

[flameport]

Diagram looks fine, other than the fan doesn't have a timed overrun (so will be on/off with the lights).
Hopefully the small boxes with 'LED' in them are the light unit and a driver.

That driver module is a poor choice, since you will need one for each LED, and it has the word 'eaglerise' on it, which is equivalent to 'failure guaranteed'

This:
http://www.ledlightingcreations.co....page.tpl&option=com_virtuemart&product_id=468
would be far better, and you only need one for the whole lot, and most of those junction boxes won't be needed either. (LEDs would be wired in series from the output).

 

[EllieP]

FAILS! Why would this be? Pure and simple old age and over-use or could there be a more scary reason?

Forty years ago when I started my career ( yes I am old ) equipment was designed by engineers to last. Now the marketing people prefer short life times to increase sales and designers tend to have to comply.

Old age for equipment was once 20 or even 40 years. Now a lot of low cost equipment is ancient by the time it reaches its second birthday if it lives that long.

Bernard ( old and often grumpy )

Thanks Bernard,

Know what you mean about things being built to give up, will have to wait and see.....

 

[EllieP]

Diagram looks fine, other than the fan doesn't have a timed overrun (so will be on/off with the lights).
Hopefully the small boxes with 'LED' in them are the light unit and a driver.

That driver module is a poor choice, since you will need one for each LED, and it has the word 'eaglerise' on it, which is equivalent to 'failure guaranteed'

This:
http://www.ledlightingcreations.co....page.tpl&option=com_virtuemart&product_id=468
would be far better, and you only need one for the whole lot, and most of those junction boxes won't be needed either. (LEDs would be wired in series from the output).

Thank you Mr Flameport,

We don't like a timed overrun on the fan - whole idea is that it goes off with the lights plus we can switch the fan off from the FCU on bad-hangover-days (on morning-after-curry-nights we just leave the lights on a few minutes longer if necessary!)

Small LED boxes are indeed the driver (from the JB) then to the LED via the connector block fitted to each LED (I just couldn't be bothered to draw the drivers as well!)

Drivers were 'recommended' by the lighting suppliers... And they told me that each LED requires a dedicated driver, and that each driver needs to have a constant 240v supply, so I wouldn't be able to just daisy-chain the drivers from a single 240v source. This is my first use of LEDs, but we intend to use them elsewhere so I will look into this for the next system. If 'eaglerise' means guranteed failure, then I may be changing the drivers in few weeks anyway! lol

Thanks again, much appreciated.