1SBL351024R8400 ABB UA50-30-00RA Contactor 3-Pole 3NO 0 Auxiliary Contacts 110V 50/ 110-120V 60Hz Coil for Capacitor Switching Applications

Why Choose the ABB 1SBL351024R8400 UA50-30-00RA-84 Capacitor Contactor?

The ABB 1SBL351024R8400, model UA50-30-00RA-84, is a specialised 3-pole capacitor switching contactor designed for switching three-phase capacitor banks used in industrial power factor correction systems. As part of the ABB UA..RA contactor series, it incorporates pre-insertion damping resistors that limit the high inrush currents generated when capacitors are energised.

Designed specifically for AC-6b capacitor switching duty, the UA50-30-00RA-84 is rated for capacitor banks up to 40 kvar at 400 V and 40 °C. The contactor's special front-mounted block inserts three damping resistors into the circuit during closing, helping reduce the initial current peak while also precharging the capacitors before the main contacts fully close.

The contactor features a 110 V AC 50 Hz / 110–120 V AC 60 Hz control coil, three normally open main poles and screw terminal connections. Its block-type construction and integrated damping resistors provide a purpose-designed solution for capacitor bank switching without requiring additional external inductances for inrush-current limitation.

Key Advantages

• Purpose-designed 3-pole contactor for capacitor bank switching.
• 40 kvar AC-6b rating at 400 V and 40 °C.
• Integrated pre-insertion damping resistors help limit capacitor inrush current.
• Suitable for installations where peak current can greatly exceed the capacitor's nominal RMS current.
• 110 V AC 50 Hz / 110–120 V AC 60 Hz control coil.
• Three normally open main contacts for three-phase capacitor circuits.
• Screw terminals provide secure industrial electrical connections.
• Block-type design supports compatible ABB auxiliary contacts and accessories.

Key Features

• ABB UA..RA capacitor contactor series.
• UA50-30-00RA-84 contactor configuration.
• 3 normally open main power contacts.
• 40 kvar rated operational power at 400 V AC-6b.
• 50 kvar UL/CSA operational power rating at 480 V.
• 110 V AC at 50 Hz / 110–120 V AC at 60 Hz control circuit.
• Special front-mounted block incorporating three damping resistors.
• Capacitor precharging helps limit the secondary current peak during contact closing.
• Main circuit rated operational voltage up to 690 V AC.
• 250,000 operating-cycle electrical durability at operational voltages below 500 V.
• Screw terminal connections for secure panel wiring.

Reliable Capacitor Switching for Power Factor Correction

Capacitor banks can produce extremely high transient currents when energised, particularly when connected alongside capacitors that are already charged. The ABB UA50-30-00RA-84 is specifically engineered to manage these demanding switching conditions through a front-mounted resistor block that temporarily inserts three damping resistors during contact closing.

The resistors help precharge the capacitor bank and reduce the initial and secondary current peaks before the main poles complete the connection. This arrangement protects the contactor and associated equipment from excessive switching stresses, making the UA..RA series particularly suitable for automatic power factor correction equipment and industrial capacitor bank installations.

Typical Applications

• Automatic power factor correction panels.
• Three-phase capacitor bank switching.
• Industrial reactive power compensation systems.
• Electrical distribution and switchgear assemblies.
• Manufacturing facility power factor correction.
• Commercial and industrial electrical installations.
• Capacitor switching applications with high inrush currents.
• OEM power factor correction equipment.