LED Tape light tripping circuit breaker

[nuelec]

Hi all just wondering if anyone knows what could be causing a problem i have on a new circuit of about 50 metres of 24v dc LED tape light. they are rated at 7 watt per metre & are connected through wise controls 0-10volt dimming pack & then via 5 100watt transformers. all operate & dimming fine but often when switched on they trip the circuit breaker. I have usede a 10amp D rated circuit breaker to handle the surge. Any idea's Thanks in advance

 

[Andy™]

dont switch all transformers on at the same time?

 

[muffin]

i ve had one hell of a day and am off to bed in a mo so.....

would i be wrong in saying

50meters * 7 watts=350 watts

350/24 volts = 14.58 amps ??

 

[Andy™]

i ve had one hell of a day and am off to bed in a mo so.....would i be wrong in saying

50meters * 7 watts=350 watts

350/24 volts = 14.58 amps ??

the MCB will be on the 230 side... so 350/230 = 1.52A

 

[rugbymacc]

use a cartridge fuse breaker instead of an MCB ?

can handle a little more inrush current .... Zs permitting

 

[Apache]

Anyone thought of using a meter to see what the surge actually is?

 

[nuelec]

Anyone thought of using a meter to see what the surge actually is?

Thanks for reply

Did that already. Running load is 2.5amp. Start up surge will be just milliseconds so will not register on a meters display

 

[nuelec]

use a cartridge fuse breaker instead of an MCB ?can handle a little more inrush current .... Zs permitting

Will look into this option but circuits are fed from new Hagar CU so could only do this if there is a cartridge fuse available as an mcb type module

 

[nuelec]

[quote name='Andy

 

[rugbymacc]

Will look into this option but circuits are fed from new Hagar CU so could only do this if there is a cartridge fuse available as an mcb type module

did one about a year ago for a hagar board .... think i got it from CEF

 

[Lurch]

Will look into this option but circuits are fed from new Hagar CU so could only do this if there is a cartridge fuse available as an mcb type module

There is, they are used quite a lot round here for some reason.

 

[muffin]

i take it you can get too the drivers ok, if so you could use a run on timmer.

set it up for a 5 second delay.

so on power up the first lot of lights will come on instantly then the second 5 seconds later.

 

[nuelec]

Sound like there maybe a fault somewhere to meTripping current of a 10 amp type d is about 140 amps

If we assume 5 x 100 watt transformer va = 500va

Primary current 500/230= 2.17 amp

if we use an assumed transformer inrush of 15 times the primary current then that equates to 15 x 2.17 = 32.55 amps, well below the tripping current

Leds inrush currents are low some are even zero

which makes me think there is a possible short between live conductors

definately no fault with the mains wiring as it is all located in the mains cupboard next to the CU. all connections have been checked for possible faults. The cable run is less than 2 metres from CU to LED drivers & dimming gear which are all connected in parallel from then on its all 24V DC.

I am increasingly inclined to thinking i have a dodgy transformer.

Thanks for all comments. Much appreciated. Somehow i'm gonna have to resolve it before my clients get ****ed at me & my reputation takes a knock. Its a brand new shop with the LED's the main feature of the decor. Tripping lights will not go down well at the opening bash . i will post the outcome here

 

[nuelec]

i take it you can get too the drivers ok, if so you could use a run on timmer.set it up for a 5 second delay.

so on power up the first lot of lights will come on instantly then the second 5 seconds later.

thats also a good idea if it is down to the surge

 

[nuelec]

I found out today from transformer manufacturers that they have a max start up current of 40amp! Nothing to do with the LED's on the load side, just a charge current which the drivers need for a milisecond or so to kickstart it. It would be nice if they put this info on some paperwork packed with the units. instead i got 5 transformers not one with any paperwork showing parameters etc. I guess my next move will be to try a 16D but even that could potentially trip on a start up surge of 200amps I am awaiting to hear back from them with a reccomended suppressor device to fit into the circuit

 

[rugbymacc]

That's a high inrush current for a small transformerTake them back and get some decent ones

+1

 

[Doc Hudson]

I found out today from transformer manufacturers that they have a max start up current of 40amp! Nothing to do with the LED's on the load side, just a charge current which the drivers need for a milisecond or so to kickstart it. It would be nice if they put this info on some paperwork packed with the units. instead i got 5 transformers not one with any paperwork showing parameters etc. I guess my next move will be to try a 16D but even that could potentially trip on a start up surge of 200amps I am awaiting to hear back from them with a reccomended suppressor device to fit into the circuit

circuit was designed by mr resistor's lighting designers with all dimming controls etc from 1 dimming pack & therefore 1 circuit. In their opinion the transformers should not be causing such a problem unless 1 of them is faulty.

Shouldn't this problem be passed back to the designers to sort out then?

Doc H.

 

[Doc Hudson]

That's a high inrush current for a small transformerTake them back and get some decent ones

Very high!

Doc H.

 

[Lurch]

I guess my next move will be to try a 16D but even that could potentially trip on a start up surge of 200amps

I think I would look at the sequential start units. You could either make one relatively easily and cheaply or there are commercially available ones, not looked at prices of those but I doubt they'll be overly cheap.

 

[nuelec]

I agree with many of the comments above. It seems unacceptably high