1SDX253991R1 ABB EPX-XT4N-E1-2503 250A 3P 36kA MCCB – LS/I

Why Choose the ABB EPX-XT4N-E1-2503 250A 3-Pole MCCB?

The ABB EPX-XT4N-E1-2503 is a high-performance 250 A three-pole moulded case circuit breaker (MCCB) designed to provide dependable overload and short-circuit protection in commercial and industrial low-voltage electrical distribution systems. Featuring a 36 kA short-circuit breaking capacity and an Ekip LS/I electronic trip unit, this circuit breaker forms part of the ABB Protecta Power Devices range and incorporates ABB's established SACE Tmax XT4N circuit breaker technology.

Unlike conventional thermal-magnetic MCCBs, the EPX-XT4N-E1-2503 uses electronic protection technology to provide configurable current thresholds and trip characteristics. Its LS/I protection system combines long-time overload protection (L) with a choice between short-time delayed short-circuit protection (S) and instantaneous short-circuit protection (I). This flexibility helps electrical designers select appropriate protection settings for the connected installation and coordinate the circuit breaker with other protective devices.

With a 250 A rated current, three-pole configuration and 36 kA breaking capacity, the ABB EPX-XT4N-E1-2503 is suitable for higher-current three-phase outgoing circuits in commercial distribution boards, industrial electrical panels and compatible ABB Protecta Power assemblies. Supplied under ABB order code 1SDX253991R1, this electronic-trip MCCB provides a versatile solution for demanding low-voltage electrical distribution applications.

Key Advantages

• 250 A rated current provides dependable circuit protection for appropriately rated three-phase electrical distribution systems.
• Three-pole (3P) configuration enables simultaneous switching and protection of three phase conductors.
• 36 kA short-circuit breaking capacity supports installations requiring substantial fault-current interruption capability.
• Ekip LS/I electronic trip unit provides configurable overload and short-circuit protection.
• Adjustable long-time overload protection (L) allows the protection threshold to be matched to conductor and circuit requirements.
• Selectable short-time delayed (S) or instantaneous (I) protection supports different short-circuit protection strategies.
• Long-time protection adjustable from 100–250 A provides flexibility for appropriately designed outgoing circuits.
• Short-circuit protection thresholds adjustable from 250–2,500 A within the Ekip LS/I protection range.
• Front-accessible DIP switches allow protection settings to be configured without complex programming equipment.
• LED status indications assist with commissioning and maintenance.
• Compact ABB SACE Tmax XT4N construction helps optimise space within electrical distribution assemblies.
• Designed for integration into compatible ABB Protecta Power distribution systems.
• Suitable for installations where adjustable trip characteristics and protective device coordination are important.

Key Features

• ABB Protecta Power Devices product group.
• ABB SACE Tmax XT4N moulded case circuit breaker platform.
• 250 A rated current.
• Three-pole (3P) configuration.
• 36 kA short-circuit breaking capacity under the applicable rated operating conditions.
• Ekip LS/I electronic protection release.
• Long-time overload protection (L) with adjustable current threshold and inverse-time trip characteristic.
• Short-time delayed protection (S) available as a selectable short-circuit protection mode.
• Instantaneous protection (I) available as an alternative short-circuit protection mode.
• Long-time current threshold: 0.4–1.0 × In.
• Long-time adjustment range: 100–250 A.
• Short-circuit threshold: 1–10 × In.
• Short-circuit adjustment range: 250–2,500 A.
• Selectable short-time delays: 0.1 or 0.2 s in S protection mode.
• Front-mounted DIP switches for manual protection configuration.
• LED indications for electronic trip-unit status and protection functions.
• Front test connector for compatible ABB Ekip testing accessories.
• Self-powered electronic trip unit under the manufacturer's specified operating conditions.
• XT4N 250 A frame with a 250 A electronic trip-unit rating.
• Manual toggle-operated switching mechanism.
• Designed in accordance with IEC/EN 60947-2.
• Designed for compatible ABB Protecta Power mounting and connection arrangements.
• ABB manufacturer order code: 1SDX253991R1.

Advanced 250A Electronic Circuit Protection with Ekip LS/I Technology

The ABB EPX-XT4N-E1-2503 combines the mechanical switching and fault-interruption capabilities of an ABB SACE Tmax XT4N MCCB with the configurable protection functions of an Ekip LS/I electronic trip unit. Electronic protection enables the circuit breaker to respond to overloads and short circuits according to selected current thresholds and time characteristics, helping protect distribution cables, connected equipment and electrical infrastructure.

The long-time protection function (L) provides adjustable overload protection for the outgoing circuit. For the 250 A electronic release, the long-time current threshold can be configured between 100 A and 250 A, corresponding to 0.4–1.0 × In. The threshold is adjustable in increments of 0.04 × In, equivalent to 10 A per step for this device. Adjustable inverse-time characteristics allow the protective response to be coordinated with the operating requirements of the installation.

The LS/I designation distinguishes this trip unit from an LSI release. The Ekip LS/I unit provides long-time protection together with a choice between short-time delayed protection (S) and instantaneous protection (I). The S and I functions are alternative short-circuit protection modes rather than independently active functions operating simultaneously. This arrangement allows the circuit breaker to be configured for either a delayed short-circuit response or rapid instantaneous interruption.

The electronic release provides a short-circuit threshold adjustment range of 1–10 × In, equivalent to 250–2,500 A for the EPX-XT4N-E1-2503. When S protection is selected, the trip unit offers short-time delay settings of 0.1 or 0.2 s. These settings can help support selective coordination with downstream protective devices, although actual discrimination must be confirmed using the relevant ABB coordination data and the installation's fault-current calculations.

For commissioning and maintenance, the Ekip LS/I electronic trip unit incorporates front-mounted DIP switches, LED indications and a test connector for compatible ABB Ekip accessories. ABB specifies self-powered operation for this trip-unit family from a minimum current of 0.2 × In under the relevant operating conditions. For a 250 A release, this corresponds to approximately 50 A through the applicable sensing arrangement.

As part of the ABB Protecta Power Devices range, the EPX-XT4N-E1-2503 is intended for installation within compatible electrical distribution assemblies. Its 36 kA short-circuit breaking capacity must be assessed against the installation's operating voltage and prospective fault current. Correct conductor sizing, protection settings and mounting accessory selection are essential for dependable operation.

Typical Applications

• ABB Protecta Power distribution boards and compatible electrical assemblies.
• Commercial low-voltage electrical distribution systems.
• Industrial electrical distribution panels and switchgear.
• Three-phase outgoing circuits requiring 250 A electronic overcurrent protection.
• Higher-current commercial building sub-distribution circuits.
• Manufacturing facilities and industrial infrastructure.
• Building services and mechanical plant distribution circuits.
• Electrical installations requiring adjustable long-time overload protection.
• Distribution systems where short-time delayed protection may support selective coordination.
• Installations requiring a choice between delayed and instantaneous short-circuit protection.
• Electrical refurbishment and distribution board upgrades involving compatible ABB MCCBs.
• Professional electrical installations requiring configurable electronic trip characteristics.