OT25G1-4BSN2 ABB OT Plus Isolator 25A 4 Pole. G1 Frame Size. Screw Terminals IP20 1SCA163436R1001

The ABB OT25G1-4BSN2 is a 25A 4-pole isolator switch from ABB's OT Plus range, designed to provide reliable electrical isolation in industrial and commercial installations. This compact G1 frame size switch disconnector delivers enhanced safety and operational flexibility for circuit protection applications. The OT Plus series represents ABB's latest generation isolator technology, offering improved performance over previous models.

Key Features

• Adjustable Fourth-Pole Timing: Allows two different time offsets within the same switch - simultaneous or early-make/late-break operation - providing greater control over switching sequences and reducing arc formation during operation.
• 25A Current Rating: Handles continuous currents up to 25A with 11kW rated power (AC-23A), making it suitable for medium-duty motor control and general switching applications.
• Flexible Cable Compatibility: Accepts flexible copper cables from 0.75-16mm² and solid copper cables 0.75-6mm², accommodating various wiring configurations without additional terminals.
• Padlockable Direct Mounted Handle: Integrated lockout/tagout capability ensures safe maintenance procedures, while maintaining full compatibility with existing OT shaft systems and external handle accessories.
• Dual Mounting Options: Base and DIN rail mounting capability provides installation flexibility in panels, enclosures, and distribution boards without requiring additional mounting hardware.
• Compact G1 Frame: Ultra-compact design at just 46mm width saves valuable panel space while maintaining full 4-pole isolation, ideal for high-density installations.
• Screw Terminal Design: Reliable screw connections with 1Nm tightening torque specification ensure secure, maintenance-friendly wiring that withstands vibration and thermal cycling.

Applications

The OT25G1-4BSN2 isolator is designed for industrial control panels, motor control centres, and electrical distribution systems where reliable circuit isolation is essential. It serves as a safety disconnect for small motors, heating elements, lighting circuits, and general electrical loads up to 25A. The adjustable fourth-pole timing makes it particularly suitable for applications requiring specific switching sequences, such as control circuit isolation that must occur before or after main circuit disconnection. The compact footprint and DIN rail mounting capability make it ideal for retrofitting existing installations or new panel builds where space is at a premium.

Standards and Compliance

This ABB isolator meets IEC 60947-3 standards for switch-disconnectors and UL 60947-4-1 certification for North American applications. The IP20 protection rating provides finger-safe protection against accidental contact with live parts, making it suitable for installation in standard electrical enclosures. The device complies with international safety standards for industrial switching equipment, ensuring reliable performance in demanding electrical environments.

Manufactured by ABB in Finland, order code: OT25G1-4BSN2 (1SCA163436R1001).

Frequently Asked Questions

What cable sizes can be connected to the OT25G1-4BSN2 isolator?

The ABB OT25G1-4BSN2 accepts flexible copper cables from 0.75mm² to 16mm² and solid copper cables from 0.75mm² to 6mm². The screw terminals should be tightened to 1Nm torque for secure connections. This wide range accommodates most standard industrial wiring without requiring ferrules or special terminals.

How does the adjustable fourth-pole timing feature work?

The adjustable fourth-pole timing allows you to configure the fourth pole to operate either simultaneously with the other three poles or with an early-make/late-break timing offset. This means the fourth pole can make contact before the main poles (early-make) or break contact after the main poles (late-break), providing controlled switching sequences for auxiliary circuits or control systems.

What are the dimensions and mounting requirements for this isolator?

The OT25G1-4BSN2 measures 68mm high, 46mm wide, and 62mm deep, with a net weight of 0.15kg. It offers both base mounting and DIN rail mounting options, providing installation flexibility. The compact G1 frame size makes it suitable for high-density panel installations where space is limited.

Can this isolator be used with existing ABB OT accessories?

Yes, the OT25G1-4BSN2 maintains full compatibility with existing OT shaft systems and external handle accessories. The padlockable direct mounted handle is included, but you can also use compatible external operating mechanisms and extension shafts from the OT range, making it easy to upgrade existing installations.

What is the difference between this OT Plus model and standard OT isolators?

The OT Plus range, including the OT25G1-4BSN2, features the advanced adjustable fourth-pole timing capability that standard OT isolators lack. This allows for more sophisticated switching control and improved integration with complex control systems. The OT Plus series also offers enhanced mechanical durability and improved contact reliability compared to previous generations.

Where can I buy the ABB OT25G1-4BSN2 switch?

The ABB OT25G1-4BSN2 OT Plus Switch is available at CSE Distributors in the UK. As an official ABB distributor with over 50 years of experience, CSE provides genuine ABB products with full warranty support. CSE Distributors has hundreds of positive reviews and is a go-to technical stockist for control panel builders and OEMs involved in the electrical automation and controls industry across the UK