ComPacT NSX250F Circuit Breaker 36kA AC 4P4R 250A Micrologic 2.2

The Schneider Electric ComPacT NSX250F C25F42D250 circuit breaker is a molded case circuit breaker with 4 poles, 250 A and a breaking capacity of 36 kA at 380/415 V AC, designed to protect low-voltage electrical distribution networks against overloads and short circuits. This reference includes a Micrologic 2.2 electronic trip unit, 4P4R configuration with all four poles protected, and fixed mounting, providing protection settings adaptable to the characteristics of the installation.

The ComPacT NSX250F is designed for commercial, tertiary and industrial installations that require high breaking capacity, electronic protection adjustment and a compact format. Its rated operational voltage reaches 690 V AC at 50/60 Hz and it is suitable for isolation in accordance with EN/IEC 60947-2.

Main features of the Schneider Electric C25F42D250

• Brand: Schneider Electric.
• Range: ComPacT.
• Family: ComPacT NSX.
• Model: NSX250F.
• Reference: C25F42D250.
• Type: molded case circuit breaker.
• Application: electrical distribution.
• Number of poles: 4P.
• Configuration: 4P4R.
• Rated current: 250 A at 40 °C.
• Trip unit: Micrologic 2.2.
• Trip technology: electronic.
• Protection functions: LSoI.
• Breaking capacity Icu at 380/415 V: 36 kA.
• Rated operational voltage Ue: up to 690 V AC.
• Frequency: 50/60 Hz.
• Insulation voltage Ui: 800 V.
• Impulse withstand voltage Uimp: 8 kV.
• Utilization category: A.
• Suitable for isolation: yes.
• Operating mechanism: handle.
• Mounting: fixed on backplate.
• Dimensions: 140 x 161 x 86 mm.
• Weight: approximately 2.8 kg.

ComPacT NSX250F molded case circuit breaker

The NSX250F belongs to Schneider Electric's ComPacT NSX family of molded case circuit breakers. It is designed to protect feeders, main switchboards and distribution lines with currents above those typically handled by conventional modular thermal-magnetic circuit breakers.

Its 250 A rating and high breaking capacity make it suitable as a main or secondary protection device in low-voltage distribution boards, provided its characteristics are compatible with the design current and the expected short-circuit level.

4 poles with 4P4R protection

The C25F42D250 reference corresponds to a 4P4R configuration, meaning four poles with protection on all four conductors. The neutral is located on the left side of the breaker.

The Micrologic unit's neutral protection allows configurations adapted to the circuit architecture, including full neutral protection at 1 x Ir in 4R configuration.

250 A rated current

The breaker has a rated current In of 250 A at 40 °C. The Micrologic electronic unit allows the overload protection threshold to be adjusted below the maximum rating of the device, providing greater flexibility during installation design and coordination.

The final current setting must be selected taking into account conductor cross-section, line current-carrying capacity, ambient temperature, switchboard architecture and coordination with upstream and downstream protection devices.

36 kA breaking capacity at 415 V

The F performance level of the ComPacT NSX250F provides an ultimate breaking capacity Icu of 36 kA at 380/415 V AC in accordance with IEC 60947-2.

Schneider Electric specifies different breaking capacities depending on the network voltage:

• 220/240 V AC: 85 kA Icu.
• 380/415 V AC: 36 kA Icu.
• 440 V AC: 35 kA Icu.
• 500 V AC: 30 kA Icu.
• 525 V AC: 22 kA Icu.
• 660/690 V AC: 8 kA Icu.

The breaker breaking capacity must be equal to or greater than the prospective short-circuit current at the exact installation point.

Service breaking capacity Ics

The technical documentation also specifies Ics values equivalent to the Icu values indicated for the main operating voltages. At 380/415 V, the breaker therefore has an Ics of 36 kA.

This feature reflects its ability to continue operating under the specified conditions after interrupting a short-circuit current corresponding to the Ics level.

Micrologic 2.2 electronic trip unit

One of the main features of the C25F42D250 is its Micrologic 2.2 electronic trip unit. Unlike a basic thermal-magnetic protection device, Micrologic uses sensors and electronics to monitor current and perform protection functions.

The unit provides LSoI functions:

• L - Long time: long-time overload protection.
• So - Short time: short-circuit protection with adjustable threshold and fixed delay.
• I - Instantaneous: instantaneous protection against high-level short circuits.

Adjustable overload protection

The long-time protection allows the breaker to be adapted to the permissible current of the circuit. For the 250 A unit, Schneider Electric specifies an Ir adjustment range from 100 to 250 A, with nine setting positions.

This makes it possible to use the same breaker on lines requiring a protection current lower than the 250 A maximum of the frame and trip unit.

Long-time delay

The operating time of the overload protection is fixed in this Micrologic 2.2 version. The technical data sheet specifies:

• 400 seconds at 1.5 x Ir.
• 16 seconds at 6 x Ir.
• 11 seconds at 7.2 x Ir.

The unit also features thermal memory for 20 minutes before and after tripping, allowing the accumulated heating of the circuit to be taken into account in its protection behavior.

Short-time short-circuit protection

The short-time protection has an Isd threshold adjustable through nine positions. The adjustment range is between 1.5 and 10 times Ir.

This setting makes it possible to adapt the short-circuit trip level to the characteristics of the circuit and facilitates coordination with other protection devices in the installation. The Tsd delay is fixed in the Micrologic 2.2 unit.

Fixed instantaneous protection at 3000 A

The instantaneous protection Ii has a fixed threshold of 3000 A. When the current reaches the instantaneous trip conditions, the breaker acts quickly to limit the thermal and electrodynamic effects of a high-intensity short circuit.

LED operating and overload indicators

The Micrologic unit includes front LED signaling to make operating status diagnosis easier:

• Green LED: indicates that the unit is ready to operate.
• Orange LED: pre-alarm when current reaches approximately 90% of Ir.
• Red LED: indicates an overload condition above 105% of Ir.

These indications make it possible to visually detect high load situations before an overload trip occurs.

No integrated residual current protection

The Micrologic 2.2 unit of this reference does not include earth leakage protection. The breaker protects against overloads and short circuits, but when residual current protection is required, an additional compatible solution must be used.

The reference also does not include standard ZSI logic selectivity.

Five slots for electrical accessories

The breaker has five slots for electrical accessories. The ComPacT NSX range allows different accessories for signaling, tripping and automation to be added according to the switchboard configuration.

Possible ComPacT platform accessories include auxiliary contacts, shunt trips, undervoltage releases, motor operators and compatible signaling accessories.

Operational voltage up to 690 V AC

The C25F42D250 can operate on AC networks up to 690 V AC at 50/60 Hz. Its rated insulation voltage is 800 V and it has an assigned impulse withstand voltage Uimp of 8 kV.

These features make it suitable for integration into professional low-voltage installations with different voltage levels, always bearing in mind that breaking capacity decreases as operating voltage increases.

Suitable for isolation

The breaker is suitable for isolation in accordance with EN/IEC 60947-2. This feature allows it to be used as a circuit isolation device within the conditions established by the manufacturer.

Standard operation is carried out using a front handle, although the ComPacT architecture supports different operating and control accessories.

Fixed backplate mounting

This reference is supplied as a fixed circuit breaker and is designed for backplate mounting inside the electrical panel.

Schneider Electric allows different installation orientations:

• Vertical mounting.
• Horizontal mounting.
• Flat installation on the back side.

Top and bottom connections are made from the front and have a 35 mm pole pitch.

ComPacT NSX250F dimensions

• Width: 140 mm.
• Height: 161 mm.
• Depth: 86 mm.
• Weight: approximately 2.8 kg.

These compact dimensions make it possible to integrate a four-pole 250 A protection device with high breaking capacity into distribution boards where space efficiency is important.

Mechanical and electrical durability

The ComPacT NSX250F is designed to withstand a high number of operations. Schneider Electric specifies a mechanical durability of up to 20,000 cycles.

Electrical durability depends on voltage and switched current:

• 20,000 cycles: at 440 V with In/2.
• 10,000 cycles: at 440 V with In.
• 10,000 cycles: at 690 V with In/2.
• 5,000 cycles: at 690 V with In.

Heat dissipation

The technical data sheet specifies a power dissipation of 17.6 W per pole. This value must be taken into account during thermal calculations and switchboard ventilation design, especially when several high-current devices are installed in the same enclosure.

IP40 and IK07 protection

Schneider Electric specifies an IP40 protection rating according to IEC 60529 and a mechanical resistance of IK07 in accordance with IEC 62262 for the conditions indicated in the product data sheet.

The final protection rating of the installation will also depend on the type of enclosure, door, front plates and accessories used in the switchboard.

Environmental operating conditions

• Operating ambient temperature: from -25 to +70 °C.
• Storage temperature: from -50 to +85 °C.
• Relative humidity: up to 95%.
• Altitude without derating: up to 2000 m.
• Maximum altitude: up to 5000 m applying the restrictions indicated by Schneider Electric.

Integration in distribution boards

The ComPacT NSX250F is intended for low-voltage distribution protection and can be used in applications such as:

• Main low-voltage switchboards.
• Secondary distribution boards.
• Industrial installations.
• Commercial and tertiary buildings.
• Infrastructure.
• Feeder protection.
• Protection of high-current lines.
• Installations requiring electronic protection adjustment.
• Networks needing a breaking capacity of up to 36 kA at 415 V.

Technical data of the Schneider Electric C25F42D250

• Manufacturer: Schneider Electric.
• Reference: C25F42D250.
• EAN: 3606482005570.
• Range: ComPacT.
• Family: ComPacT NSX.
• Model: NSX250F.
• Type: molded case circuit breaker.
• Application: distribution.
• Number of poles: 4P.
• Protected poles: 4R.
• Neutral position: left.
• Rated current: 250 A at 40 °C.
• Operational voltage Ue: 690 V AC.
• Frequency: 50/60 Hz.
• Icu at 220/240 V: 85 kA.
• Icu at 380/415 V: 36 kA.
• Icu at 440 V: 35 kA.
• Icu at 500 V: 30 kA.
• Icu at 525 V: 22 kA.
• Icu at 660/690 V: 8 kA.
• Ics at 380/415 V: 36 kA.
• Trip unit: Micrologic 2.2.
• Technology: electronic.
• Protections: LSoI.
• Ir protection range: 100-250 A.
• Ir settings: 9 positions.
• Isd range: 1.5-10 x Ir.
• Isd settings: 9 positions.
• Instantaneous protection Ii: fixed at 3000 A.
• Thermal memory: 20 minutes before and after tripping.
• Integrated residual current protection: no.
• ZSI: no.
• Slots for electrical accessories: 5.
• Ui: 800 V.
• Uimp: 8 kV.
• Utilization category: A.
• Suitable for isolation: yes.
• Actuation: handle.
• Mounting: fixed on backplate.
• Mounting positions: vertical, horizontal or flat on the back side.
• Width: 140 mm.
• Height: 161 mm.
• Depth: 86 mm.
• Weight: approximately 2.8 kg.
• Power dissipation per pole: 17.6 W.
• Mechanical durability: 20,000 cycles.
• Protection rating: IP40.
• Impact resistance: IK07.
• Operating temperature: -25 to +70 °C.
• Storage temperature: -50 to +85 °C.
• Altitude without derating: up to 2000 m.

Electronic 250 A protection for power distribution

The Schneider Electric ComPacT NSX250F C25F42D250 combines a 250 A rating, four protected poles and a breaking capacity of 36 kA at 415 V with the flexibility of a Micrologic 2.2 electronic trip unit. The adjustable long-time protection between 100 and 250 A and the short-time threshold between 1.5 and 10 times Ir make it easy to adapt the breaker to the actual characteristics of the protected line.

Its suitability for isolation, operational voltage up to 690 V AC, LED status and overload indicators, five accessory slots and compatibility with the ComPacT NSX accessory platform make this reference an especially suitable solution for professional power distribution switchboards.

The final configuration of the Micrologic settings must be based on the installation calculation, conductor cross-section and thermal capacity, the expected short-circuit current and the selectivity and coordination study with the rest of the protection devices.