I just ordered a pentair color changing LED light to replace the old regular light in the pool that has tripped the gfi since we moved in. The bulb I removed from the current fixture while troubleshooting is 120V and 500w. Will I need to buy a transformer for the new 12V LED light, or is the transformer built in? When I ordered it I pictured just pulling the new wires, splicing it in, and I'd be good to go. Now I'm thinking there's a bit I may have overlooked, not to mention more equipment to purchase! Thanks!