see my edit ^^^
If you have 2 relays you can do it on the line side. you need 2 timers 1 for ea relay. 1 on 1 off then it reveres. The off is now on the on is now off. really easy to do. The schematic I posted is for only a single ballest flip.
In your drawing the relay would go right above the timer. You would not need those extra outlets. Its simple my friend... 1 ballest is on the other is off the timers tell when ea ballast turns on. Typically people use 1 ballest like the schematic I posted that for a single ballest 2 light flip..
the relay will be fine
for a 2 ballast 4 lamp show you will need 2 relays
considering the low cycling duty of a flip if using cap and core ballasts cold switching isn't necessary
if this is a DIY project be sure that the wiring around the relay doesn't interfere with the moving parts of the relay
FWIW the proper box for these relays try square d #9991UE1 this makes the job easier and better looking
hey rives you seem to be pretty knowledgeable in this area.
Read through the thread but didn't see an exact answer.
So you cannot connect 2 ballasts using 1 DPDT relay for 4 lights?
pigtailing the connections wouldn't work???
Thanks id advance