GFCI (Ground Fault Circuit Interrupt), outlets are the usuaal way of implementing ground fault protection. This safety device breaks the circuit if some of the current fed into the load is not returning. These devices protect outlets that may come in contact with water. There is a Test and a Reset button on the device that allow the user to test if the protection works properlyas well as to turn it back on.
1. Disconnect all loads from the circuit in order to protect them as well as to make sure that the potential cause of the tripping is removed.
2. Press the button that says Reset (often colored red).
3. Connect the loads back and test if they function properly.
For more information go to the Ground Fault Circuit Interrupter (GFCI) page.