If you use only one ECM with KCM or ChromaPad, you can use only one power adapter with a splitter. But if you decided to use more than one ECM, you should use one power adapter for every four ECM's with a splitter.
Let's asume that you have one KCM and four ECM's. You need one adapter to power KCM and ECM. And also you need one adapter to power other three remained ECM's.
So in total for one KCM and 4 ECM, you will need 2 power adapter and 3 splitter.