Connect your transformer to the feeder track using the cable provided. Different manufacturers use different connectors; your instruction sheet will show the proper way to make the connection for your set.
Before plugging the transformer into an electric outlet make sure that the throttle is set to zero ("stop" on the power pack in the photo) and that there is nothing laying across the rails.
Before plugging the throttle into an electric outlet, be sure that the throttle is set to zero. You want to be sure that there will be no power to the rails when the transformer is plugged into the wall.

