Frustrated - Need an answer

[kentd]

This has happened several times and I do not understand why this happens.
I will use the example of a couple of groups of Dalek Mini Trees the first was a group of four trees and the second was a group of six trees. These are 2811 nodes and each group runs off of one plug on a Falcon 16V2 with power being added to each tree after the first one, in other words only the first 60 pixels run off of the plug from the controller and each subsequent 60 pixels run independently with their own power source. The problem I have run into is when they were first fired up the fuses on the independent power caused fuses to blow. I then check to make sure there is not any wiring that could be connected wrong causing +12 to be to Ground. The only way I seem to get these running is to take each tree and put an amp meter into the circuit and connect the +12 and Ground and then turn on using test, once this is done and it lights I can then connect through the fuse and everything is OK once everything is connected using this amp meter process then all of the trees can be connected correctly and they now work as they should with no problem. These trees are connected to the same power supply as well as the plug on the controller is from the same supply. I don't know if this phenomenon the very first time is because of something unique to spanning Universes or not but I have never had to change anything except using the amp meter and starting one by one until they are all on line. I hope someone can shed some light on why this happens, it's really frustrating.
Thanks
Kent

[Gilrock]

It would be easier to help if you could draw up a sketch of how the wires are connected.  From the description there's no way to know whether power lines are running out serially or connected or bridging back to other strings and how grounds are connected and what size fuses are blowing and where they are located.

[kentd]

Gil I used Hella Fuse Blocks connected in a CG1500 Case with 7.5 amp Blade Fuses. I have the 8 Terminal using two of these for four 12 Volt power supplies with each four terminals bused together for one power supply. This then feeds through a 7.5 amp fuse with power to the model coming off of the buss. The Trees do not feed 12+ through the 3 connector plug only ground and data. The power comes in from a 2 connector plug that then feeds the 12+ and ground part of the subsequent tree. Only two trees are connected to the spade part of the fuse output which should not exceed 5.44 Amps max. No 12+ goes back to any other string.
The first tree which is 50 pixels for the tree and 10 for the star come off of the controller plug for 12+, Ground, and Data. Only the Ground and Data come out of the tree so the next two trees come off of a power spade fuse and feed only the 12+ and ground of each tree separate from each other.

All Grounds are connected to a common Ground Buss that connects the controller and power supplies together as well as the ground side of any wires that would be connected to the fuse spade output from the Hella block.
I am not sure how to draw a diagram that could be posted
 

[Gilrock]

Its sound ok but it's hard to visualize just reading text.  I don't think bridging universes could have anything to do with blowing a fuse.  That should just be pure power draw.

[Steamyrotter]

What current draw were you getting??

It could be inrush current taking the fuse out on first power??

Are your supplies well regulated, and not susceptible to surge or droop??

[kentd]

The power supplies are 12 Volt 350 Watt that were purchased from Holiday Coro on a presale and an initial surge could be what is happening.
I have attached a picture of the CG1500 and at the top you can see the Hella Fuse Block, the rest of the board and fuse blocks are for the Mega Tree - 12 160 string lights, they only have the data coming from the controller and the power from the fuse blocks. They are the white cables, the Dalek Trees are the Black with the six on the far left feeding the six trees and the four on the middle the four trees. The two conductor plugs are spliced into a set of two output cables and one #10 Wire (Red) connected to the spade output from the hella block. Plug 14 is the three conductor for the four trees and plug 15 is the three conductor plug for the six trees. One Tree of the four and one tree of the six are connected to the same wire.
Tree 1 - 3 conductor - Power from plug 14 controller 2.72 Amps
Tree 2 - 2 conductor - Power Spade Fuse 1
Tree 3 - 2 conductor - Power Spade Fuse 1
Tree 4 - Split 2 part of 2 conductor - (Spade fuse 2)
Four Tree Group
Six Tree Group similar 3 Conductor plug 15 and the remainder of the Spade Fuses
Total Power should not exceed 27.2 Amps max with full all lit 100% White

[Steamyrotter]

350w gives total avail current of just over 29 amps so somewhere you may have exceeded current draw on one or more areas..

You could try splitting your fusing down even more so that you have less per fuse.
Not sure if you can do that on your setup there??

Maybe even powering minimum of one item per group from the controller board may reduce the currents in the others sufficiently therefore protecting against premature fuse failure??

[kentd]

First of all Thank You for your responses to this question, I just want to figure out why.

I want to examine the word INRUSH, Is this something that would always occur on start up? The reason I ask that is this has only occurred the first time any model that exceeds 170 pixels.
The Mega Tree Strands are 160 pixels each and when I connected four strands to one power supply there was not any problem.

What I did was when the top three fuses blew I hooked up the Fluke meter to the buss side and then stuck the probe to the output side of the fuse, the lights turned on and the amp draw was in the range it should be. I then put a new fuse in that circuit and proceeded to do the same thing with the next one. Same effect and new fuse. Again repeat and same thing. Now all six trees working. Turn off everything turn back on no problem it works just like it is supposed to.
 
Is this something that is power supply side related rather than model related? Like Capacitance? Because of the load the first time that more pixels being triggered by the data request would require in the model? It would seem like NO as turning on say four strings of 160 pixels each should have the same effect on power requirements.

The only time this has happened before was with a matrix of 600 Pixels that was to be used with our concession stand. Fuses blew then went through the same process as described above, matrix turned on correctly. This is run by a Raspberry PI and once it worked all we did the rest of the summer was plug it in, the PI turned on the matrix worked fine all Summer long no problem.

This seems to only be a problem with larger models and with the data set to run all say 600 pixels from one plug thus requiring power to be distributed throughout the model.
BTW Thanks for input on this
Kent

[Gilrock]

Just remember the fuses don't care about anything but how many amps are flowing through the wire.  Crossing a universe boundary will be more data being pushed out that data line and its trying to push that extra data at a specific rate so the total average power could go up.  Some of us are engineers we don't read paragraphs that well but we do read electrical drawings and our eyes latch on to actual current values.  So when you say you checked the current show us the numbers to keep our brain active. Too many words in a row without pictures and numbers and we lose focus.

But seriously I would try to draw it out in pencil, or MS Paint, or an online drawing tool even if its just to have as your own reference.

[Steamyrotter]

inrush is basically the starting current so to speak

When ever you turn a PSU on you will get a surge of current, sometimes higher than the continuous rated current. and the expected current for the applied load.
This is due to many factors including capacitance of the system, inductance, reluctance and resistance (depending upon the true setup of the system) and can be affected by poor regulation and smoothing of the PSU Used.  (don't even get into AC and HV Theory here.....)
Even something as benign as temperature can have an effect as this will alter the electrical characteristics of the system as a whole...

An example industrial motors can and will take up to 8 times full load current to start up..even if there is no load attached to the end of it..
Same thing can happen in smaller lighter loaded circuits...  hence why you need to ensure your fusing discrimination (ie the ratings of the fuses at particular points of your distribution network) is correct.

If you are running near to the fuse / circuit rating then the easier and more likely it is for the surge to pop the fuse...

That is why I suggest either splitting it more, or look to re-distribute the load a bit..

[Gilrock]

That's why they have slow-blow fuses.

[Steamyrotter]

Or motor rated fuses....


What ever you do please don't bypass them with a bit of wire....
They are there for a reason.

[kentd]

Thanks for your help
Gil I used MS Paint to draw a diagram of the buss and the four fuse outputs with labels.
If needs be I could change the fusing to say 10 Amp Spade instead of 7.5 I just used 7.5 x 4 = 30 Amps
I guess the frustrating part is this has only happened the very first time of powering up the display. Once they have all lit up then it never happens again. Maybe on future display models just bring them online by not going thru the fuses but the amp meter to make sure there is not a problem.

Using the fuse blocks was to protect things that is why I put them in to begin with.

Again Thank You

[Steamyrotter]

Loads theoretically within the fuse ratings at nominal voltage.

Would be interested to see what the voltage and current traces are on power up

If the PSU voltage overshoots on power up then that could cause the issue

[Gilrock]

So which fuse is blowing?