Convert Three-Way to Single Pole Smart Switch

[MangoTango]

All, I'm a bit stumped trying to convert a three way traditional switch over to the Smart Caseta Single Pole On/Off switch. There are two switches today for a light, the plan is to convert one switch to the Smart switch, then add a secondary remote to the alternate switch location - essentially no longer using the wiring between both switches.

I am thrown off on the ceiling gang box that appears to feed the hot wire. See attached image overview. The switch wire White was going to Hot Black. The Light wires (both same color)... One went to pig tailed Whites in gang, The other went to Black that routed to switch box (not to the bulk of pig tailed blacks).

Caseta Single Pole switch has Black, Red, White and a Blue (not used). Manual said to connect B-B, R-R, W-W.

See attached. What is the consensus on this one to get this wired correctly?

 

[Lucien Nunes]

You have a problem there, because the smart switch requires a neutral therefore three wires (hot, neutral and switched hot) plus ground. are required from the ceiling to the wall box. Your existing wiring has only two plus ground.

You will either need to replace the cable from the ceiling, pick up a neutral from another point on the same circuit, or change to a smart switch that doesn't require a neutral (although these can be quirky.)

I notice that you describe connection 'A' in the ceiling as testing hot, which is not normal as it is the neutral. I wonder exactly how you tested it? If it was by measuring the voltage relative to ground, there may be a disconnected ground on this circuit, and in fact the ground was testing hot relative to the neutral.