RV Trailer Camper Electrical Management System Hardwire 50A/240V EMS-LCHW50 Surge Protector; Protect From Damaging Low/ High Voltage Levels and Power Surges When Connected To AC Power Supply; 50 Amps; Automatically Disconnects When Voltage Falls Below 104 Volt Or Raises Above 132 Volt and Automatically Reconnects Once Voltage Stabilizes; With Fault Indicator; With Plug Head Handle Grip; With Amperage Meter/ Voltage Meter/ Frequency Meter; With 5 Mode Surge Protection Whenever AC Power Falls Below 104 Volt, Or Rises Above 132 Volt, The EMS Automatically Shuts Down Power To The RV. If The AC Power Is Interrupted, Or The EMS Detects A Fault Condition, The Built-In Time Delay Is Activated 5-Mode Surge Protection: This Feature Provides Full Surge Protection. Features Surge Indicator, Reverse Polarity Protection, Open Neutral Protection, Open Ground Protection, AC Frequency Protection, Accidental 240 Volt Protection Enclosed Blue Jumper Wire Allows The User To Bypass The Computer Circuit In The EMS In The Event Of Computer Failure, Thus Allowing AC Power Into The RV. Replacement Parts Are Designed For Simple Plug And Play, Making Repairs Extremely User Friendly Microprocessor Controlled: The Computer Is Driven By A State-Of-The-Art Microprocessor That Is Programmed With Software To Drive The Entire EMS