Kussmaul Electronics Co. Inc. 091-134A, Auto Interlock III is a power transfer relay which automatically transfers the 120 volt A.C. from the shoreline to the auxiliary generator when the generator is started. Easy to install, indicator lights are provided to indicate which input is active and is being supplied to the load. Once installed, operation is automatic, and does not require an operator's intervention. As soon as the generator is started, the relay removes the load from the shoreline input, and applies it to the generator. When the generator is shut down, the load is returned to shore power.