How do I chain this? The book shows how to wire a 3 means of access switch...
The book shows how to wire a 3 means of access switch and a double gang single pole switch but not double gang 3 way switches.
I'm thinking: run two black pigtails sour the line from the panel. Tie the three whites together and the three grounds together (plastic box). That results surrounded by four blacks and two reds for the two switches. Yes, almost or buy more insurance?
Answers: In the box where you are making the connections, the black line or wires coming in should be bringing the power contained by from the panel (really one is enough) they or it goes to the single screw on the switches. The other wires (travelers) walk directly to the same screw on the second set of 3-way switches.
The Black wire from respectively of the 2nd set of 3-ways (one will go to respectively separate lighting circuit).
Now you need a indeterminate (preferably white) to go to respectively light and this will not be connected to any of the switches.
Here is where on earth you can save time and trouble.
1- There really is no inevitability for the neutral to run through the switch box unless it's already there.
2- The ground Bare or green other gets connected together contained by all boxes and the green screw on the switches and fixtures as very well.
3- The travelers can be Red and White or Black and Red.
(don't get them mixed near the Power In Wire(s).
Well this should be enough to variety it work ( you're not confused) [took me 3 years to finally see the 3-ways are really quite simple - later add contained by 4-ways]
Good Luck, hope this helps ! ! !