ABB Tmax XT4S 250 Molded Case Circuit Breaker

Overview

The Tmax XT4S 250 is part of ABB’s innovative Tmax XT family of molded case circuit breakers (MCCBs). It is engineered for performance and simplicity, meeting the needs of modern electrical installations. The XT4 frame size covers currents up to 250 A, and the "S" designation indicates a standard breaking capacity suitable for most industrial and commercial applications. This breaker is compliant with international standards IEC 60947-2 and UL 489.

Key Features

• Rated Current: 250 A (adjustable from 160 A to 250 A with electronic trip unit).

• Breaking Capacity: Up to 55 kA at 415 V AC (Icu) according to IEC.

• Protection Functions: Available with thermal-magnetic (TMD) or electronic trip units (Ekip) for LI (overload and short-circuit) or LSI (with short-time delay) protection.

• Selectivity: Enhanced selectivity thanks to adjustable time delays, enabling coordination with downstream devices.

• Communication: Optional Ekip Com modules enable integration into fieldbus systems (Modbus, Profibus, DeviceNet) for remote monitoring and control.

• Accessories: Wide range of internal and external accessories including auxiliary contacts, shunt trips, undervoltage releases, and motor operators.

Technical Specifications

• Number of Poles: 3-pole or 4-pole versions.

• Rated Operational Voltage (Ue): up to 690 V AC 50/60 Hz.

• Rated Insulation Voltage (Ui): 800 V.

• Rated Impulse Withstand Voltage (Uimp): 8 kV.

• Utilization Category: Category A (for TMD) or Category B (for Ekip with selectivity).

• Mechanical Endurance: 25,000 operations.

• Electrical Endurance: 10,000 operations at rated current.

• Operating Temperature: -25°C to +70°C (without derating up to 50°C).

• Dimensions (WxHxD): 3-pole: 105 x 205 x 94 mm; 4-pole: 140 x 205 x 94 mm.

Trip Unit Options

The XT4S 250 can be equipped with either fixed thermal-magnetic trip units (TMD) or interchangeable electronic trip units (Ekip). The Ekip family includes Ekip L/I (basic LI protection) and Ekip LS/I (with selectivity). Electronic units offer advanced measurements (current, energy, power) and diagnostic functions via the front display or remote communication.

Applications

• Main switchboards and distribution panels in commercial buildings.

• Industrial machinery control panels.

• Motor control centers (MCC).

• UPS input/output protection.

• Renewable energy installations (PV inverters, wind turbines).

Installation and Maintenance

The breaker features a compact design for easy installation on DIN rail or mounting plate. Terminals accept copper or aluminum cables. Routine maintenance includes checking tightness of connections and cleaning of insulating parts. The trip unit can be tested using portable test kits without disconnecting the breaker.

Certifications

• IEC 60947-1, IEC 60947-2.

• UL 489 (cULus listed for applicable versions).

• CCC, EAC, and marine certifications (ABS, DNV, etc.) on request.

Note: This document provides technical information only; refer to the ABB Tmax XT catalog for detailed selection and ordering data.