1SDX254851R1 ABB EPX-XT5N-E2-6303 630A 3P 36kA MCCB – LSI

Why Choose the ABB EPX-XT5N-E2-6303 630A 3-Pole MCCB?

The ABB EPX-XT5N-E2-6303 is a high-performance 630 A three-pole moulded case circuit breaker (MCCB) designed to deliver dependable overload and short-circuit protection in demanding low-voltage electrical distribution systems. Featuring a 36 kA short-circuit breaking capacity and an advanced Ekip Dip LSI electronic trip unit, this circuit breaker belongs to the ABB Protecta Power Devices range and incorporates ABB's established SACE Tmax XT5N circuit breaker technology.

Engineered for commercial and industrial power distribution, the EPX-XT5N-E2-6303 combines high-current circuit protection with configurable electronic trip characteristics. Its LSI protection system provides long-time overload protection (L), short-time delayed short-circuit protection (S) and instantaneous short-circuit protection (I). These functions offer electrical designers flexibility when configuring protective thresholds, coordinating upstream and downstream circuit breakers, and protecting cables and electrical equipment against abnormal current conditions.

With a 630 A rated current, three-pole configuration and 36 kA breaking capacity, the ABB EPX-XT5N-E2-6303 is particularly 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 1SDX254851R1, this electronic-trip MCCB provides a reliable solution for installations requiring robust fault interruption and adjustable overcurrent protection.

Key Advantages

• 630 A rated current provides dependable protection for appropriately designed high-current three-phase distribution circuits.
• Three-pole (3P) configuration enables simultaneous switching and protection of three phase conductors.
• 36 kA short-circuit breaking capacity supports installations with substantial prospective fault currents.
• Ekip Dip LSI electronic trip unit delivers configurable overload and short-circuit protection.
• Long-time overload protection (L) helps protect cables and equipment against sustained excessive current.
• Short-time delayed protection (S) supports selective coordination with downstream protective devices.
• Instantaneous protection (I) provides rapid interruption during high-current short circuits.
• Separate L, S and I protection functions offer greater configuration flexibility than LS/I releases with alternative S or I operation.
• Electronic protection technology enables adjustable current thresholds and trip characteristics.
• Front-accessible DIP-switch settings provide straightforward protection configuration.
• ABB SACE Tmax XT5N construction combines high-current capability with robust moulded case design.
• Fixed-mounted, front-terminal platform supports integration into compatible electrical distribution assemblies.
• Designed for use within compatible ABB Protecta Power distribution systems.
• Suitable for electrical installations where protection coordination, reliability and maintainability are important.

Key Features

• ABB Protecta Power Devices product group.
• ABB SACE Tmax XT5N moulded case circuit breaker platform.
• 630 A rated current.
• Three-pole (3P) configuration.
• 36 kA rated short-circuit breaking capacity at 415 V AC.
• Ekip Dip LSI electronic protection release.
• Long-time overload protection (L) with adjustable electronic settings.
• Short-time delayed short-circuit protection (S) for protection coordination.
• Instantaneous short-circuit protection (I) for rapid fault interruption.
• Independent L, S and I protection characteristics for flexible circuit protection.
• Electronic overcurrent sensing rather than conventional thermal-magnetic trip technology.
• Front-accessible DIP switches for protection setting adjustments.
• Trip-unit status and protection indications to assist commissioning and maintenance.
• XT5N 630 A frame with a 630 A electronic trip-unit rating.
• Fixed-mounted circuit breaker construction.
• Front-terminal connection arrangement on the corresponding XT5N LSI breaker.
• 690 V AC rated operational voltage for the corresponding XT5N circuit breaker platform.
• 1,000 V rated insulation voltage and 8 kV rated impulse withstand voltage.
• Manual toggle-operated switching mechanism.
• Designed in accordance with IEC/EN 60947-2.
• Designed for installation using compatible ABB Protecta Power mounting and connection accessories.
• ABB manufacturer order code: 1SDX254851R1.

Advanced 630A Electronic Circuit Protection with Ekip LSI Technology

The ABB EPX-XT5N-E2-6303 combines the mechanical switching and fault-interruption capabilities of an ABB SACE Tmax XT5N MCCB with the configurable protection characteristics of an Ekip Dip LSI electronic trip unit. This combination enables the circuit breaker to respond to overload and short-circuit conditions according to selected current thresholds and operating times, helping protect electrical cables, connected equipment and distribution infrastructure.

The long-time protection function (L) responds to sustained overload conditions. Adjustable electronic settings allow the protection threshold and operating characteristic to be matched to the electrical installation's expected load, conductor ratings and design requirements. This helps reduce the risk of thermal damage caused by prolonged excessive current while supporting appropriate operation of the protected circuit.

The short-time protection function (S) provides a configurable response to short-circuit currents with an intentional delay where required. This can be particularly useful in larger distribution systems where protective device selectivity is important. By coordinating the upstream MCCB with downstream circuit breakers, electrical designers can help minimise unnecessary disconnection of unaffected circuits during a fault. Actual discrimination must be verified using ABB's published selectivity data and the installation's prospective fault-current calculations.

The instantaneous protection function (I) provides rapid interruption when the current reaches the configured instantaneous threshold. This function helps limit the duration of high-current short circuits. The Ekip LSI configuration includes long-time, short-time delayed and instantaneous protection characteristics for adjustment, unlike an Ekip LS/I release, which offers a choice between S and I short-circuit protection modes.

The ABB SACE Tmax XT5N 630 A frame provides a robust platform for high-current electrical distribution. Its fixed-mounted construction and front-terminal arrangement support integration into compatible switchgear and distribution assemblies. The corresponding XT5N circuit breaker platform is rated for operation at voltages up to 690 V AC, although its available short-circuit breaking capacity varies according to the operating voltage.

The three-pole design provides coordinated switching and overcurrent protection of the three phase conductors in an appropriately designed three-phase electrical system. As a three-pole device, it does not provide a fourth switched neutral pole. The standard LSI trip unit provides overload and short-circuit protection rather than residual-current or earth-leakage protection, so any required additional protective functions must be specified separately.

For ABB Protecta Power installations, the XT5 platform is intended for higher-current outgoing circuit applications. Where larger conductors require additional wiring space, a side cableway extension box may be appropriate, subject to the distribution board arrangement and manufacturer's installation guidance. Correct cable terminations, mounting accessories, protective settings and enclosure selection are essential for dependable performance.

The EPX-XT5N-E2-6303 has a specified 36 kA short-circuit breaking capacity at 415 V AC. Before installation, the circuit breaker's interruption capability must be assessed against the prospective fault current at the relevant operating voltage. Protection settings should also be selected in accordance with the electrical design, applicable regulations and ABB's technical documentation.

Typical Applications

• ABB Protecta Power distribution boards and compatible electrical assemblies.
• Higher-current commercial low-voltage electrical distribution systems.
• Industrial electrical distribution panels and switchgear.
• Three-phase outgoing circuits requiring 630 A electronic overcurrent protection.
• Commercial building main and sub-distribution assemblies.
• Manufacturing facilities and industrial electrical infrastructure.
• Building services and mechanical plant power distribution.
• Electrical installations requiring adjustable long-time overload protection.
• Distribution systems where short-time delayed protection supports selective coordination.
• Installations requiring separate long-time, short-time and instantaneous protection characteristics.
• Electrical refurbishment and distribution board upgrades involving compatible ABB MCCBs.
• Professional electrical installations requiring high-current electronic-trip circuit protection.