If I understand correctly, you have Leviton florescent dimmer
And you want to connect dimmer to Lutron ECO-series ballast This is the ballast with 3 wires
: Hot dimmed, Neutral and HotIs this your dimmer
???? Has Black, White, Red, Yellow-red, & OrangeHere's how to do it
Dimmer yellow-red is not used except for 3-way switch >> cap it off with wire nut
Dimmer orange wire connects to ballast Dimmed Hot
Dimmer red wire connects to ballast Hot
Dimmer white wire connects to ballast Neutral
Those are your wires going to ballast. As you can see, you need 3 wires going to florescent fixture
Next, let's focus on Dimmer:
Dimmer green wire goes to bare ground wire
Dimmer black wire connects to Hot from breaker box (we'll test for that next)
Finally the Dimmer white wire connects to ballast Neutral as discussed above BUT is also has to connect to Neutral from breaker box
This means the Dimmer white wire is connected to 2 wires
>> one wire goes to florescent fixture and the other wire comes from breaker box
So which wires come from breaker box??
It should be a black and white wire.
Let's test to find Hot and Neutral that come from breaker box.
Mark your wires.
Disconnect all the wires and separate from each other
Turn on power
Use ordinary tester
Tape tester leads to wood sticks so hands stay away from electricity
Power is on
Test each wire to bare copper wire
When tester lights up, that is Hot from breaker box ... this wire connects to Dimmer black wire
Now, test the hot wire to each of the other wires
When tester lights up, that is Neutral wire ... this wire connects to Dimmer white wire, and also connects to Ballast neutral.
Connect one wire at a time, and it will work.