Auto Transfer Relay System 30 AmpHigh/Low Voltage Protection: Whenever AC power falls below 104 Volt, or rises above 132 Volt, the EMS automatically shuts down power to the RV. The EMS will monitor the power and once the AC power rises above 104 Volt, or below the 132 Volt level, the time delay indicator flashes for the preset time and then automatically restores power to the RV. Time Delay for A/C Compressor: If the AC power is interrupted, or the EMS detects a fault condition, the built-in time delay is activated.Automatically sense generator power and prevents shoreline and generator power entering the AC distribution panel at the same time and ruining your camping experience! Features include heavy duty relays that prevent contact damage during high current transfer operation, a time delay circuit board to ensure generator voltage is at the proper level before transfer occurs, a protective, snap-on cover with a wiring schematic mounted inside the cover.Features:Whenever AC Power Falls Below 104 Volt, Or Rises Above 132 Volt, The EMS Automatically Shuts Down Power To The RVIf The AC Power Is Interrupted, Or The EMS Detects A Fault Condition, The Built-In Time Delay Is Activated3-Mode Surge Protection: This Feature Provides Full Surge ProtectionFeatures Surge Indicator, Reverse Polarity Protection, Open Neutral Protection, Open Ground Protection, AC Frequency Protection, Accidental 240 Volt ProtectionEnclosed 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 RVReplacement Parts Are Designed For Simple Plug And Play, Making Repairs Extremely User FriendlyMicroprocessor Controlled: The Computer Is Driven By A State-Of-The-Art Microprocessor That Is Programmed With Software To Drive The Entire EMSAutomatically Reconnects: YesWeight: 2.7500Voltage Regulation: 120 VoltAmpere Rating: 30 AmpUsed To: Protect From Damaging Low/ High Voltage Levels and Power Surges When Connected To AC Power SupplyWith Fault Indicator: YesWith Plug Head Handle: No