1. Application Scope
The RSB5-125 is a high-current miniature circuit breaker in the 125A series, designed for short-circuit and overload protection. It is suitable for lighting distribution systems and motor power distribution systems. Featuring a compact and lightweight design, it offers excellent performance, high reliability, and superior breaking capacity. The breaker has a quick tripping mechanism and supports rail-mounted installation. Its housing and components are made of high flame-retardant, impact-resistant plastic, ensuring a long service life. It operates in AC systems at 50Hz or 60Hz with a single-pole rated voltage of 230V and two-, three-, or four-pole rated voltage of 400V. It is designed for rated currents ranging from 50A to 125A, providing overload and short-circuit protection while also supporting infrequent switching of electrical devices and lighting circuits under normal conditions.
The breaker can be equipped with additional accessories, such as undervoltage release devices and shunt trips. It can also function as an isolator switch, provide undervoltage protection, and enable remote disconnection for circuits.
The RSB5-125 complies with IEC60947-2, GB14048.2, and GB10963 standards.
2. Model and Specifications
Product Model Poles Tripping Type Rated Current (A)
RSB5-125 1P C (Standard) 125
? Number of Poles:
1P, 2P, 3P, 4P
? Tripping Type:
C: C-curve
D: D-curve
? Rated Current (A):
63, 80, 100, 125
3. Normal Working and Installation Conditions
3.1 Ambient Temperature:
? Upper limit: +40°C
? Lower limit: -5°C
? 24-hour average: ≤+35°C
3.2 Installation Altitude:
? ≤2000m
3.3 Relative Humidity:
? At +40°C: ≤50%
? Higher relative humidity allowed at lower temperatures (e.g., 90% at +20°C), with consideration for condensation due to temperature changes.
3.4 Pollution Degree: 2
3.5 Installation Environment:
? Free from significant shock, vibration, or explosive media.
? Free from corrosive gases, conductive dust, and rain/snow exposure.
3.6 Installation Method:
? Mounted on TH35-7.5 rails.
? Installed in distribution boxes, cabinets, or enclosures.
? Typically mounted vertically with a maximum tilt of ±5°. The handle’s upward position indicates power ON.
3.7 Installation Category: III
4. Technical Parameters
? Rated Current: 63A, 80A, 100A, 125A
? Rated Operating Voltage: 230/400V AC
? Breaking Capacity: 10kA
? Indicator Window:
? Green: Contacts are open.
? Red: Contacts are closed.
? Impulse Withstand Voltage: 4kV
? Rated Insulation Voltage: 500V
Accessories:
? OF Auxiliary Contact
? MX+OF Shunt Trip
Tripping Characteristics:
? C-Curve: Protects standard loads and distribution cables. Magnetic tripping at 8.5In ±20%.
? D-Curve: Protects high inrush loads (e.g., transformers). Magnetic tripping at 12In ±20%.
Torque Specifications:
Rated Current (A) Screw Size Rated Torque (N·m) Max Torque (N·m) Standard Torque (N·m)
63–125 M7 4.0 5.5 3.5
Current Correction Values at Different Temperatures:
Temperature (°C) Correction Factor
-35 to +70 Values vary based on rated current. Detailed chart available upon request.
Current Correction Coefficients at Different Altitudes:
Altitude Correction Coefficient
≤2000m 1.0
2000–3000m 0.9
≥3000m 0.8
Mechanical and Electrical Lifespan:
Rated Current (A) Loaded (cycles) Unloaded (cycles)
63, 80, 100 1500 20000
125 1000 20000
5. Features
? High short-circuit breaking capacity.
? Red-green safety indicator enhances safety.
? Energy storage mechanism ensures fast contact closure, improving lifespan by mitigating variations in manual operation speed.
? Wiring: Suitable for 16–50mm2 cables with a terminal tightening torque of 3.5N·m.
For more detailed specifications and charts, please contact us directly.
