LED Tape Current Surge

[jlee0119]

Hello all, recently I have been working on a show where we are trying to control LED tape using a DMX controller. We were able to get it to work straight from our ETC Element, but when we tried plugging in the DMX from one of our lights on stage instead of the board it sparked and blew the fuse inside the AC to DC converter we used to power the LED Controller. The DMX controller uses 3 pin DMX and and I have no idea why it would make the fuse blow. Any Ideas? Thank You.

Below are the LED tape, the DMX controller, the power supply, and the light that the DMX is coming from we used. Ultimately the DMX is coming from a show baby and running through a couple lights.

DMX Controller: http://www.amazon.com/dp/B00B42M3RG/?tag=controlbooth-20

LED Tape: http://www.amazon.com/dp/SUPERNIGHT/?tag=controlbooth-20

Power Supply: http://www.amazon.com/dp/B00DKSI0S8/?tag=controlbooth-20

LED coming from this light: http://www.amazon.com/dp/B00BAXJEAS/?tag=controlbooth-20

 

[StageTech620]

I am not in anyway an electrican, but I have worked with this "generic" LED tape before. A few things should be checked.

1. Is there something going on inside the Chauvet LED unit, that is shorting the DMX connection?
2. Is the DMX Cable Shorting?
3. Is your power supply powerful enough to support the LED strips?

These are only the first few things that come to mind.

 

[gafftaper]

First of all, the link to you LED tape doesn't seem to work. but it was easy enough to find a wide variety of supernight LED tape online.

This doesn't make much sense. So DMX, comes into a unit and is converted into some mysterious protocol that the LED tape talks. The AC/DC converter is powering that conversion process, but there shouldn't be any way for power from the DMX line to go backward up into the converter and damage it. They DMX signal and the DC power should never directly be in direct contact. DMX is data, the DC is power for the conversion process. Even if it did meet, how could it hurt the device? The converter is putting out 12 volts DC and DMX is only 4.5 volts. Although I doubt it is at fault, it would be worth putting a test meter on the DMX out of the Chuavet light to be sure it's 4.5 volts. I have the feeling the timing is random coincidence and it's just the results of using several Chinese products none of which are exactly "professional grade".

Perhaps our friends from Chauvet @Ford or @Ben Dickmann will have some ideas.

 

[JChenault]

This doesn't make much sense. So DMX, comes into a unit and is converted into some mysterious protocol that the LED tape talks. The AC/DC converter is powering that conversion process, but there shouldn't be any way for power from the DMX line to go backward up into the converter and damage it.


Perhaps our friends from Chauvet @Ford or @Ben Dickmann will have some ideas.

Just to clarify. The controller is essentially a low voltage dmx controlled dimmer. It gets fed 12 volts from the power supply, and outputs to three dimmers via a connector block. The only thing I can think of that would make the power supply blow a fuse ( by the way, the Amazon page does not show a fuse in the power supply) would be if you were trying to pull more power than the supply can handle. The power supply looks to be rated at 3 amps, so this would be one amp per color in the LED strip. This is not much.

My suspicion would be that you either connected too many strips to the controller, or that you have an issue with the terminal strip.

If you want to test this, there are some "Auto" modes in the controller you can access by flipping the first dip switch. Disconnect the DMX cable, and try some auto modes and see if that blows the power supply.

How many feet of strips are you trying to use? And how many LED lamps n a roll?

 

[gafftaper]

Yeah @JChenault you are right simply overloading the power supply's max output makes the most sense. @jlee0119 Did you by chance add a few more strings of LEDS to the draw between tests, so that it ran fine, you added more lights and then it popped? This could also just be a factor over time. If you were right near the 3 amp maximum the power supply might have been fine pushing a little too much power for a bit, but then it gave out.

 

[theatricalmatt]

Is it possible that the wires supplying the V+/V- and any one of the RGB outputs either got cross-plugged, unplugged and re-plugged into the wrong thing, or otherwise short-circuited? Since the DMX controller shows you would need to strip back insulation to connect to the terminal block on the controller, was too much insulation stripped back? Was there a nick in the insulation further back from the termination point?

 

[jlee0119]

Yeah @JChenault you are right simply overloading the power supply's max output makes the most sense. @jlee0119 Did you by chance add a few more strings of LEDS to the draw between tests, so that it ran fine, you added more lights and then it popped? This could also just be a factor over time. If you were right near the 3 amp maximum the power supply might have been fine pushing a little too much power for a bit, but then it gave out.

We only had 1 16 foot strand connected. We tested it before moving it to the set piece it was going on. We even tested it with the manual DIP controls. upon further inspection we found that one of the pins on the 3 pin cable was singed a bit.

Just to clarify. The controller is essentially a low voltage dmx controlled dimmer. It gets fed 12 volts from the power supply, and outputs to three dimmers via a connector block. The only thing I can think of that would make the power supply blow a fuse ( by the way, the Amazon page does not show a fuse in the power supply) would be if you were trying to pull more power than the supply can handle. The power supply looks to be rated at 3 amps, so this would be one amp per color in the LED strip. This is not much.

The fuse is built into the power supply. We took the power supply apart and it was a small glass fuse that blew up.

 

[FMEng]

If pin 1 was burned, then you had a big voltage potential between the controller and the DMX source. Given that, and the fact that most switching power supplies have over-current protection, I think you have a dangerously defective power supply. At least nobody was electrocuted.

 

[randiculous]

Hello all, recently I have been working on a show where we are trying to control LED tape using a DMX controller. We were able to get it to work straight from our ETC Element, but when we tried plugging in the DMX from one of our lights on stage instead of the board it sparked and blew the fuse inside the AC to DC converter we used to power the LED Controller. The DMX controller uses 3 pin DMX and and I have no idea why it would make the fuse blow. Any Ideas? Thank You.

Below are the LED tape, the DMX controller, the power supply, and the light that the DMX is coming from we used. Ultimately the DMX is coming from a show baby and running through a couple lights.

DMX Controller: http://www.amazon.com/dp/B00B42M3RG/?tag=controlbooth-20

LED Tape: http://www.amazon.com/dp/SUPERNIGHT/?tag=controlbooth-20

Power Supply: http://www.amazon.com/dp/B00DKSI0S8/?tag=controlbooth-20

LED coming from this light: http://www.amazon.com/dp/B00BAXJEAS/?tag=controlbooth-20

That Chauvet light you have linked is battery operated. Is your LED fixture running on battery power in your scenario? It is possible that power could come out of that fixture, that it is spitting out some power over the DMX data out. Put a meter between each of the pins on the DMX out of the LED fixture and see what you're getting - if it's a lot of volts ( in the range of >5) I'd say you've got a short or a crossed wire on that LED par that's causing power to come out the DMX line. That power could very easily go into your DMX decoder and cause some damage.

You mentioned singing on one of the pins on the 3 pin cable. Try metering between that pin and pin 1 first on your EZ par.

 

[Josh Rawls]

It sounds to me like you had a ground loop. If the light fixture and the LED strip power supply were plugged into different 120v circuits and one or both of those circuits had a wiring issue the DMX cable became the ground between those units. That is the spark that you saw when you plugged in the DMX cable.

Do yourself a favor and measure the voltage between pin 1 on the light fixture and pin 1 on the LED power supply with both plugged into the same power you previously had them plugged into. I think you will see at least a few volts. If it is over 5 volts I would start looking into the power outlet wiring.