1SBN060300R1000 ABB RA5-1 Surge Suppressor Module for Contactors

Why Choose the ABB 1SBN060300R1000 RA5-1 Interface Relay?

The ABB 1SBN060300R1000, also known as the RA5-1, is a compact 24 V DC interface relay designed to connect low-power PLC outputs and other electronic control signals to ABB power contactors. Developed as an accessory for ABB contactor systems, it receives a low-power 24 V DC control signal and provides sufficient switching capability to operate the coil of a compatible contactor.

The RA5-1 incorporates a miniature electromechanical relay with a normally open (NO) contact and a low-consumption 24 V DC coil. The PLC or control device energises the interface relay coil, while the relay's normally open contact switches the power contactor coil. This arrangement provides an effective interface between sensitive electronic control equipment and higher-power electromagnetic contactor coils.

To improve control-system reliability, the RA5-1 incorporates integrated surge suppression. A diode suppresses overvoltage on the 24 V DC interface relay coil, while a varistor suppresses transients generated by the power contactor coil. An additional diode between the E1 and E2 input terminals provides reverse-polarity protection. The RA5-1 is designed for compatible ABB A9 to A110 contactors with 24–250 V AC, 50/60 Hz coils.

Key Advantages

• Provides a reliable interface between 24 V DC PLC outputs and ABB contactors.
• Low-consumption 24 V DC relay coil is suitable for low-power electronic control signals.
• Integrated diode surge suppression protects the interface relay control circuit.
• Built-in varistor suppression helps limit overvoltage from the contactor coil.
• Reverse-polarity protection helps protect the relay against incorrect input connection.
• Compact design integrates directly with compatible ABB contactor control systems.

Key Features

• ABB RA5-1 interface relay.
• 24 V DC rated control circuit voltage.
• Miniature electromechanical relay construction.
• 1 normally open (NO) switching contact.
• Low-consumption coil designed for PLC and electronic controller outputs.
• Compatible with contactor coil voltages from 24–250 V AC at 50/60 Hz.
• Integrated diode suppression on the 24 V DC relay coil.
• Integrated varistor suppression on the power contactor coil circuit.
• Diode protection against relay input polarity reversal.
• Screw terminals for secure electrical connections.

Reliable PLC-to-Contactor Interface for Industrial Control

PLC and electronic controller outputs often provide insufficient power to operate larger electromagnetic contactor coils directly. The ABB RA5-1 provides an intermediate switching stage, allowing a low-power 24 V DC control signal to energise the interface relay while its normally open contact controls the associated power contactor coil.

Switching inductive contactor coils can generate voltage transients that may adversely affect electronic devices, insulation and component service life. By integrating diode and varistor surge suppression together with reverse-polarity protection, the RA5-1 provides a practical solution for improving the reliability of PLC-controlled contactor installations.

Typical Applications

• PLC-controlled motor starters.
• Industrial machinery and automation systems.
• ABB A-series contactor control circuits.
• Motor control centres and electrical panels.
• Conveyor and material handling systems.
• Production and process automation equipment.
• Industrial control circuits requiring isolation between low-power controls and contactor coils.