Electrical Help Needed! (relaying a 400w ballast)

So what im trying to do is have my electronic ballast power a hps light for 12 hours of the day and then use the relay in this picture to switch to my veg room for the other 12 hours. (maybe 15 minutes of break for the ballast i realize they shouldnt run 24/7) but somethings's not right here the plug that looks like the standard plug from my hps hood is throwing me off. i believe that there is one ground and 2 outputs to the bulb but when i put the relay on it doesn't actually switch it. i've tested all the parts with others to make sure they work except maybe powering the mh using the standard socket and mogul adapter attached to the ballast. please help! where do i put the relay in? or do i need a bigger handling relay? (trying to do this with what i have)

relay specs: 12vdc 30/40 A; 14vdc NC30A N040A

nobody knows?