Single-phase automatic mains failure (AMF) controller SZR-277

Automatic switchover to backup power – reliability and comfort

The SZR-277 backup start controller is an intelligent solution for ensuring uninterrupted power supply in the event of a mains failure. The device automatically switches the power to an alternative source, such as a generator, guaranteeing continuous operation of critical devices and systems. This is particularly important in single-family homes, small businesses, and anywhere where a power outage can cause serious losses or hazards.

The SZR-277 is designed to operate in single-phase installations with a voltage of 230V AC. Its task is to monitor the voltage parameters in the network and react immediately to any irregularities. When a voltage drop or failure is detected, the controller starts the generator and switches the power to its output. After the voltage is restored in the main network, it automatically returns to normal operating mode after a short stabilization period.

Functionality and application

The SZR-277 controller finds wide application in various areas:

• Home installations: Ensuring continuous power supply for devices such as pumps, alarm systems, emergency lighting or garage gates.
• Small businesses: Protection against losses caused by power outages for servers, cash registers, monitoring systems and other key devices.
• Critical installations: Emergency power supply for devices requiring uninterrupted operation, e.g. in hospitals, laboratories or pumping stations.

Thanks to its compact size (3 modules – 52.5 mm), the SZR-277 controller is easy to mount on a standard DIN rail. The device is characterized by high reliability and durability, which ensures long-term and trouble-free operation.

Key features and parameters

SZR-277 offers a range of functions and parameters tailored to the needs of users:

• Supply voltage: 85÷265 V AC – a wide range of input voltages ensures compatibility with various installations.
• Maximum switching current: 16 A/250 V AC – allows controlling loads with significant power consumption.
• Programmable times: The ability to set the blackout delay time (1÷15 s), the time to qualify the line as good (10 s) and the generator start-up time (5÷120 s) allows for precise adjustment of the controller's operation to the specifics of the installation.
• Contact configuration: 3 × NO (normally open) – allows flexible connection to external contactors or switches.
• Operating temperature: -25 ÷ 50 °C – ensures reliable operation in a wide range of ambient temperatures.
• Protection class: IP20 - protection against touching with fingers and solid objects with a diameter greater than 12.5 mm.

The controller does not have phase sequence control, phase failure detection or over/under voltage control – it is a basic model designed for simple backup power applications. Its main advantage is reliability and ease of configuration for basic needs to ensure uninterrupted power supply.