A new mega tree requires new wiring. I have 96 strands in a zig-zag (up-down-up-down) configuration, 4 per channel (24 channels). Power is injected at the base (bottom) of each strand. Previous setup had all 96 strands sending 3-wire, 18# (0.75mm2) conductors in a sheath into 8 boxes. Now I have to consolidate into two boxes. 48 3-conductor cables is a lot per box.

The power/current requirements and voltage drop are manageable with a larger-gauge "feeder" from the box supplying all 4 strands for a channel. That reduces the cabling to 12 per box. It all works out well. However...

I've never been able to find a really bullet-proof way to create a weatherproof 'Y' connection. Simple inline splices with lined heat shrink on each conductor, and another including all conductors in the cable, are simple. Anything more than a 1-to-1 (inline) connection poses a risk of moisture penetrating in the "crotch" of the 'Y'. I can try adding some silicone sealer, but I'd hate to have to redo almost 100 cables if that doesn't work. My previous setup was bulky, but bullet proof in terms of weather proofing; all connections were done inside the weatherproof box. Now I'm possibly trading bulk for problematic connections in the weather.

My climate is high mountain (>8000' elevation) with lots of precip, cold and wind (first season of this), so I'm looking for those with experience and suggestions to share what has worked for them. Thanks in advance.