LED power supply blowing LED controller

[Bonesey2000]

Hi,

I bought an LED bundle online. It comprises of;

LED AC to DC psu 12A 15V
LED controller wifi
15m LED strip (5m x 3)
3 way splitter

When ever I plug the LED controller to the psu it blows, circuit board fried on the controller. The controller input read 5-24V.

I have used a multimeter to check the outpit, it reads a steady 12v, however amps is 19A. When I use the multimeter to check the output I use the un fused 10A setting on the multimeter, a few sparks later it reads 19A and the wires are very hot, close to melting after a few seconds.

Any guidance much appreciated!

Thanks

 

[telectrix]

either wired incorrectly or fauly equipment. is it Chinese?

 

[Wilko]

Hi - if I understand correctly you’re measuring 19A from a 12A supply and cabling is hot to touch. This is indicates too much current flowing compared with design. But you probably already knew that. You could try running just one led string and see if that will work, but it sounds like the controller is smoked? If it’s not a wiring error then perhaps the 15m of leds is just too much load and they need to be split across more transformers and controllers.

 

[Bonesey2000]

Hi - if I understand correctly you’re measuring 19A from a 12A supply and cabling is hot to touch. This is indicates too much current flowing compared with design. But you probably already knew that. You could try running just one led string and see if that will work, but it sounds like the controller is smoked? If it’s not a wiring error then perhaps the 15m of leds is just too much load and they need to be split across more transformers and controllers.

Every chance it could be a wiring error, but I don't see how, you will have excuse my newbie ignorance.

What incorrect wiring issue would cause this to happen? I wired a mains plug to the PSU (positive, neutral and earth) then measured the output of the PSU. I also have the switch set to 220v input rather than 110, altho the input is actually 240v as its UK mains power.

Not sure what could have possibly gone wrong?

Thanks for such rapid responses, great community!

 

[Wilko]

Hi - The transformer, controller and cables are being overloaded for some reason. You may’ve done everything correctly, but the system may be under engineered and so doomed to smoke itself. I’d try to get it to run with only 1 led string. If you’d like to post up some pics of the kit and cables there may be more to seen ...

 

[Bonesey2000]

Hi - The transformer, controller and cables are being overloaded for some reason. You may’ve done everything correctly, but the system may be under engineered and so doomed to smoke itself. I’d try to get it to run with only 1 led string. If you’d like to post up some pics of the kit and cables there may be more to seen ...

No worries, will get on it later today and post pics... Can't wait to be informed of the glaringly obvious issue!

 

[DPG]

How are you connecting your multimeter when you measure the current?

 

[Bonesey2000]

How are you connecting your multimeter when you measure the current?

Not sure what you are asking, there is currently only one way isn't there? I have also put an online fuse on, it blows a 10A but doesn't blow 20A
[automerge]1578844455[/automerge]

[automerge]1578844538[/automerge]
Here are some photos guys, any help appreciated

 

[DPG]

What I mean is where are you connecting the meter leads to when you are measuring the current?

 

[Bonesey2000]

What I mean is where are you connecting the meter leads to when you are measuring the current?

I have tested the psu itself, wires connected to the psu and connection blocks connected to the wires.

 

[DPG]

In your OP, you say that when you measure the current there are sparks and the wires get hot. Have you connected your meter to the positive and negative outputs of the power supply?

 

[static zap]

Can you unplug the black Jack connector ,from LED unit
and do a Picture of Innards of white lead you connect it to. (If possible to see !)
(strange how cables are marked "Plus and Minus")
For image 20200112_154
... If cabling is getting warm -sounds like a Short circuit....
(May be damage from getting polarity of DC output wrong )

 

[westward10]

That driver needs containing in an enclosure so live terminals are not exposed.

 

[freddo]

+1 for checking the polarity. The white stripe on the black cable would usually be +, from your photo it looks like the striped wire is in the - terminal.

 

[Bonesey2000]

+1 for checking the polarity. The white stripe on the black cable would usually be +, from your photo it looks like the striped wire is in the - terminal.

Hmmm... Does the multimeter not read negative if polarity is not correct? I've had the striped wire in + during all testing also

In your OP, you say that when you measure the current there are sparks and the wires get hot. Have you connected your meter to the positive and negative outputs of the power supply?

Yes, is this not correct?

 

[freddo]

Hmmm... Does the multimeter not read negative if polarity is not correct? I've had the striped wire in + during all testing also

Ah ok, the photo wasn't clear.

Yes, is this not correct?

No, not for most applications anyway. For current measurement the meter needs to be in series with the circuit. If you tested a meatier power supply or the mains that way it would blow up in your face.

 

[DPG]

This was what I suspected you were doing, hence my previous questions. A multimeter, when used on the amps setting, is effectively a short circuit across the input sockets. So this is the reason for the hot cables and sparks when you are measuring the current.

As Freddo says - connect the meter in series with the positive output lead.

 

[Bonesey2000]

This was what I suspected you were doing, hence my previous questions. A multimeter, when used on the amps setting, is effectively a short circuit across the input sockets. So this is the reason for the hot cables and sparks when you are measuring the current.

As Freddo says - connect the meter in series with the positive output lead.

Ah OK, however, this may prove difficult as it's blown the LED controller, which is the initial problem.

Might I add the LED lights seem to work fine with the blown controller, just I can't control them, they all stay white...

 

[static zap]

If things light OK , polarity must be OK.
(chinese labeling always a bit hit and miss)
(When it was controllable -may have been interesting to have seen the DC voltage feeding the controller , when it was dim/OFF if that option existed)
(.. Checking regulation of PSU for a light load !..)

 

[Bonesey2000]

First of all apologies for the delay in getting back to you guys, hectic week.

I have just manager to do some more testing.

I swapped the polarity and the LED's did not light up, as expected, so I don't think it is that.

I have used my multimeter in series and connected to the blown controller, this is only recording 0.8amps and is lighting up the LEDs.

I have blown 2 controllers so far, however, the last one that blew was connected without any LEDs attached, could this have caused a short to blow it? I do not recall how I blew the first one, whether it was connected or not but I thought I'd ask first as I don't want to have to waste another £10 on trial and error.

If there is anything else you think I could do to work out this issue it would be greatly appreciated.

 

[DPG]

Are you sure you hadn't had your multimeter connected to it in ammeter mode on the previous occasion?

 

[Bonesey2000]

Are you sure you hadn't had your multimeter connected to it in ammeter mode on the previous occasion?

Sorry not sure what you are asking? Connected to what?

 

[DPG]

Just wondered if you had tried measuring the output current after the controller and damaged it.

 

[Bonesey2000]

Just wondered if you had tried measuring the output current after the controller and damaged it.

Oh I see, no always before the controller and also didn't measure anything before the first one blew

 

[static zap]

With the PSU on but no LED light controller attached ,
get the multimeter set to volts DC and measure if the power supply goes over 18V between terminals 5 & 6.
This is a no load test , and may be how delicate electronics,that may only need 3A come to an end on a 15A supply .
( some 3A or 5A fuses may reduce the chance of mishaps with thin wiring on DC 12V-18V )