electrical
Hope the subject was clear. If not…
I have 2 3-way switches on my hallway. If both are in the same position (either off or on) the lights are on. If they are opposite the lights are off. Other than turn one switch upside down, what could be the wiring issue?
Thanks in advance!
Here is an educated guess.....
Here's what you can do with existing cables in wall.
The black-red grouped pairs are messengers. On 3-way switches, "C" marks the common.
That's the sure way to do this thing, but it's a little complicated. In this case you re-task red as a signal line (as needed by the smart switches).
Best Answer
This is how 3-ways work
You have described what is utterly normal for 3-ways. If you don't like opposite=off, do as brhans says in his answer that he's about to write. And I'm with you, I do that all the time.
Or go another way with a relay
You can't just use random relays out of the Mouser catalog. However they make mains-wiring-listed relay modules legal for this, and they fit in a junction box knockout or inside a box.
Use a latching relay. This has two coils and a common. Energize one coil, the relay throws on and stays. Energize the other, the relay throws off and stays. Energizing need be only momentary.
You use these with a special momentary SPDT (in other words, a 3-way) switch that lives in the middle position until you push it up or down. Now you can use the 3-way switch wiring to carry common and two coils.