Fusing Injection lines

[jediknight2]

My setup is as follows: I have a 12v 350w power supply, it powers my string of 256 pixels. I have power at the beginning fed directly by the controller. I then have power injection from the SAME power supply at the beginning of each 100 ct string. So, wires coming off of power supply powering controller and 2 injection points. From my understanding, I don't benefit in this situation by fusing my V+ lines....is this correct?

 

[Gilrock]

If your saying the injection wires provide a direct route to the power supply with no fuse then I don't think that's good. I'm using a P12S which has fused outputs to the strings and for my power injection wires I bought a second P12X card so that my injection wires would be fused. I had considered running the injection wire into the same connector as the string so that both strings would run from that fuse but its only a 7.5 A fuse and each string was 5 A so I had to run my injection wire through a second fuse.

 

[jediknight2]

I should also clarify that EACH power injection from the power supply is a separate run. I don't run a power injection and drop off it it and continue on. If I inject in two spots, it is a separate injection from the PS to each injection spot.

 

[Gilrock]

I'm glad you brought this up because it got me thinking about my setup. I'm in a room full of EE's so I just discussed the setup with them. We decided each power injection line really needs a fuse. The plan I had I don't think would work well because it basically would put two fuses in parallel so it would make it harder for a fuse to blow if a short happens. So even when running the power injection from the same power supply it would be best to cut the power wire between the pixels at the injection point so that only the injection wire is feeding the power. That way each injection wire only has one current path back to the power supply and each would be fused.