@rlithgow1 - Rick, sorry for the delayed response, I was traveling this week, and didn't have time to dig up the specifics below. But bottom line, I think your PS will be fine, and yes breaking things into separate 5M sections, and injecting power on both ends should work - My guess is that with 5M you'll have color issues with just power from the supply end (that data signals can only be injected from one end, and flow unidirectionally along the strip) - Power can come from either end, and you can even inject power in the middle of the strip, if needed. - So I think with a bit of testing on power feeds, all that will be fine with 5V.
My concern, with what you typed above, is the feeder runs of 16' of 22AGW wire. My gut says that is too thin of wire. - The specifics are from any of your favorite AI below, but MAX current for a 22AGW is 7A, or with 5V, just 35W. - And more typical limits (to avoid heating in a wooden residential wall) is likely 3A, or just 15W - That's not a lot.
My electrician l pushed me to use 18G wire, and I'm running 24V strips, so the current (and heat) are typically is less than 2A. Personally, I'm sure that 20AWG would have worked as well, but he is the electrician, and this got inspected by the town, and I didn't want insurance hassles down the road in case of any issues - Just buy thicker gauge feeder wire, seemed like a small concession to make my electrician happy - I was more interested in PixelBlaze coding for the segments, HE interfaces, etc. - I also added external fusing to the power supply feed, and each strip feeder cable given the 24V - I couldn't do that natively in the PB. I think your DrZZ controller has internal 5V fuses, so you may be all set there.
In summary, So I think you're strips will work (I would have preferred the 12V, but with feeds on both ends, of a single 5M strip, you should be fine). And a 300W power supply (60A) should be fine. - My only concern would be your feeder wire gauge - As it really depends on if all the strips will be at 100% brightness for long periods, in terms of each strips current load.
But your electrician may have different feelings on this, so you do you..
Current Limits (Ampacity)
The maximum safe current for a wire depends heavily on how it is installed (e.g., in free air, bundled with other wires, or within a conduit). The ratings below are general guidelines for copper wire.
| AWG Gauge | Max Amps for Power Transmission (bundled) | Max Amps for Chassis Wiring (free air) |
|---|---|---|
| 22 AWG | 0.92A - 3A | ~7A |
| 20 AWG | 1.5A - 5A | ~11A |
| 18 AWG | 2.3A - 7A | ~14A (at 60°C) |
Voltage Drop
Voltage drop is a function of current, wire length, and the inherent resistance of the wire material. It becomes more critical in low-voltage DC systems (like 12V or 24V). A common recommendation is to keep voltage drop under 5% of the total circuit voltage.
- Calculation Formula (DC circuits): Vdrop = 2 × I × R × L (where I is current, R is resistance per unit length, and L is one-way length).
- Resistance per 1000 ft (approximate for copper):
- 22 AWG: ~16.1 Ohms/1000 ft
- 20 AWG: ~10.15 Ohms/1000 ft
- 18 AWG: ~6.385 Ohms/1000 ft
Example Voltage Drop (for a 10 ft / 3 m run carrying 2 Amps at 12V):
- 22 AWG: Results in a voltage drop of ~0.3V (~2.5% of 12V).
- 18 AWG: Results in a voltage drop of ~0.12V (~1% of 12V).
For longer runs or higher currents, a thicker (lower AWG) wire is needed to minimize voltage drop and prevent potential overheating.
