# RGB arch setup for power

#### Nodent

##### Apprentice elf
I like pictures, suck at math.

I have 7 arches in series with 100 5v pixels each.

Arch1 = 100 pixel string 20 foot arch
Arch2 = SAME but 10 feet away from Arch1
Arch3 = repeat
What's wrong with this picture?

Nodent

#### fasteddy

##### I have C.L.A.P
Global moderator
For 100 pixels on each arch with 10 foot space between arches at 5vdc you will need injection between each arch and I would be considering using 16 gauge cable for the distances you want as voltage drop is your biggest enemy with this setup. A string of 50 5volt pixels sometimes needs its own injection at the end depending on the cable size used and the distance and you want to run 100. As well with your power injection you cable must be large enough to handle the current that will be drawn by 100 pixels and 22 gauge wont suffice. Also each injection point will need its own supply cable from the power supply.

In this type of setup it is sometimes better to split the power supplies up and run 2 or 3 separate power supplies so you can minimise the injection run distance and thus reduce the initial lead in cable voltage drop. In fact I think this may be the only way you can do this as you are talking 200 feet from end to end using 5vdc and 700 pixels and small gauge cable.

12vdc lights may have been a better choice for long runs like this as you get away with a larger voltage drop margin than if using 5vdc, but there are trade offs either way.

#### Nodent

##### Apprentice elf
Does it matter what side I inject the power from? the end of the string or the front?

I would like to inject at the end of the string then the beginning of the next string in the series, of course severing thepositive and separating to have the same potential for each.

#### ChristmasInKaralee

##### Senior elf
Someone correct me if I'm wrong, however I think your last comment is a great idea and will use it myself, however you should disconnect the +V wire on the connections between the arches where there is no power injection.

#### ԆцряєсϮ

##### Senior elf
Not if your using the same power supply, you want all the positives connected to share the load and therefore reduce voltage drop.

#### AussieDoug

##### Full time elf
Only a trivial one from me which is WS2811 pixels only have 3 wires, +ve, data, -ve. Providing they are what your planning on using.

#### arw01

##### Full time elf
In general you can inject power from either end, but I saw one string on Ray's site that said NOT to inject from the opposite end, so I would post what you are buying and have the group comment if they have done it or see any issues with it.

Larger wire would be good for the number of amps you will be running and the voltage drop, but as Eddy said, I think some smaller more frequent supplies would be a good idea and they give you more flexibility down the road. I picked up a 7A unit from Ray with my order for like \$8.00 and it ran 4x93 pixel arches just fine.

Alan