Schneider NS630N Molded Case Circuit Breaker (3P, 630A, STR23SE)

The Schneider NS630N is a high-performance molded case circuit breaker from the NS600N series, designed for main and branch protection in low-voltage electrical networks. Rated at 630A with 3 poles, it is equipped with the STR23SE electronic trip unit, providing adjustable overload and short-circuit protection with an integrated ground fault function.

Electrical Characteristics

• Rated current (In): 630 A

• Number of poles: 3P (3-pole)

• Rated operational voltage (Ue): 690 V AC 50/60 Hz

• Rated insulation voltage (Ui): 800 V

• Impulse withstand voltage (Uimp): 8 kV

• Breaking capacity (Icu) at 415V: 50 kA (NS630N version)

• Breaking capacity (Icu) at 690V: 20 kA

STR23SE Electronic Trip Unit

The STR23SE trip unit provides:

• Long-time protection (L): Ir = 0.4-1 x In, tr = 0.5-20s

• Short-time protection (S): Isd = 1.5-10 x Ir, tsd = 0.1-0.4s (I²t on/off)

• Instantaneous protection (I): Ii = 2-15 x In

• Ground-fault protection (G): Ig = 0.2-1 x In, tg = 0.1-0.8s

The trip unit is powered from the line side (no external supply needed). It features a digital display showing real-time current values, trip cause, and settings. Password protection prevents unauthorized changes.

Mechanical Construction

The breaker has a robust molded case of glass-fiber reinforced polyester (UL94 V-0). It features a rotary handle with ON/OFF positions and a trip-free mechanism. The terminals accept copper or aluminum cables up to 2x 240mm² or single 400mm². It has a positive contact indication (green = OFF, red = ON).

Accessories and Auxiliaries

Compatible accessories include:

• Shunt trip (MX) – 24/48/110/220V AC/DC

• Undervoltage release (MN) – 24/48/110/220V AC/DC

• Auxiliary contacts (OF) – 1NO+1NC or 2NO+2NC

• Alarm contact (SD) for trip indication

• Motor mechanism (MCH) for remote operation

• Terminal shrouds and phase barriers

Indicators and Communication

The STR23SE includes an LED for overload pre-alarm and a digital screen. Optional communication module (COM32) for Modbus RTU allows remote monitoring of currents, trips, and settings via a supervisory system.

Environmental Specifications

Operating temperature: -25°C to +70°C (derating above 55°C). Storage: -40°C to +85°C. Humidity: 95% at 55°C. Altitude: up to 2000m without derating. Protection degree: IP20 front, IP00 terminals.

Standards and Certification

IEC 60947-2, UL 489 (with certain ratings), CSA C22.2 No. 5. CE marked, CCC, EAC, RoHS. Marine classification (DNV, GL, LROS) optional.

Dimensions and Weight

Dimensions (H x W x D): 255mm x 185mm x 110mm. Weight: 5.2 kg. Mounting: screw fixing on a mounting plate. Recommended torque: 25 Nm for main terminals.

Typical Applications

The NS630N is used as main incoming breaker for industrial switchboards, motor control centers (MCC), distribution panels, and generator protection.

Conclusion

The Schneider NS630N with STR23SE trip unit provides comprehensive, adjustable protection in a compact MCCB, suitable for demanding power distribution applications.