Product Overview
The QKB3 series high-breaking miniature circuit breakers (MCBs) are engineered for AC 50/60Hz power systems with a rated voltage of 230/400V and rated currents ranging from 6A to 80A. They provide reliable overload and short-circuit protection for electrical lines and support infrequent switching operations under normal working conditions.
Suitable for a wide range of scenarios including industrial facilities, commercial buildings, high-rise residences, and civil dwellings, the product complies with the national standard: GB/T 10963.1-2020 Electrical accessories – Circuit-breakers for overcurrent protection for household and similar installations – Part 1: Circuit-breakers for AC.
Model Selection Guide
| Code Segment | Definition | Options & Specifications |
|---|---|---|
| QKB3 | Product Code | High-breaking miniature circuit breaker |
| 80 | Frame Grade Rated Current (Inm) | 80A (fixed for this series) |
| 2P | Pole Number | 1P, 2P, 3P, 4P |
| C | Trip Type | C: C-type tripping curveD: D-type tripping curve |
| 63 | Rated Current (In) | 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A, 80A |
| OF | Accessories | OF: Auxiliary switchSD: Alarm switchOF+SD: Auxiliary + AlarmMX: Shunt trip |
Notes on Accessories
- All accessories can be assembled and disassembled independently on the circuit breaker.
- Combined assembly options: ① Shunt trip + Auxiliary contact; ② Shunt trip + Auxiliary alarm contact.
Functional Characteristics (Tripping Test Criteria)
| No. | Rated Current of Trip Unit (In, A) | Initial State | Test Current | Specified Time | Expected Result | Remarks |
|---|---|---|---|---|---|---|
| 1 | 6, 10, 16, 20, 25, 32, 40, 50, 63, 80 | Cold State | 1.13In | t ≤ 1h | No Trip | – |
| 2 | 6, 10, 16, 20, 25, 32, 40, 50, 63, 80 | Post Test 1 (Hot State) | 1.45In | t < 1h | Trip | Current rises to the specified value stably within 5s |
| 3 | In ≤ 32In > 32 | Cold State | 2.55In | 1s < t < 60s1s < t < 120s | Trip | – |
| 4 | 6, 10, 16, 20, 25, 32, 40, 50, 63, 80 | Cold State | 5In10In10In14In | t ≤ 0.1st ≤ 0.1st ≤ 0.1st < 0.1s | No TripTripNo TripTrip | C-typeC-typeD-typeD-type |
Technical Specifications
| Item | Unit | QKB3-80 |
|---|---|---|
| Frame Grade Rated Current (Inm) | A | 80 |
| Rated Current (Ie) | A | 6, 10, 16, 20, 25, 32, 40, 50, 63, 80 |
| Pole Number | – | 1P, 2P, 3P, 4P |
| Rated Working Voltage (Ue) | V | 1P: AC230V/AC400V; 2P/3P/4P: AC400V |
| Rated Frequency (f) | Hz | 50 |
| Rated Insulation Voltage (Ui) | V | 500 |
| Rated Impulse Withstand Voltage (Uimp) | kV | 6 |
| Rated Short-Circuit Capacity (Icn) | kA | 6 |
| Rated Operational Short-Circuit Capacity (Ics) | kA | 6 |
| Service Life (Cycles) | ||
| Mechanical Life | Cycles | 10000 |
| Electrical Life | Cycles | 4000 |
| Mounting Form | – | 35mm standard DIN rail |
| Overall Dimensions (mm) | ||
| Width | mm | 1P: 18; 2P: 36; 3P: 54; 4P: 72 |
| Length | mm | 85 |
| Height | mm | 75 |
Appearance and Installation Dimensions
Ordering Instructions
Orders must be placed in accordance with the model selection guide, with complete configuration information.
Order Format
Product Name + Model & Specification + Quantity
Specification Description Elements
- Breaker name (Miniature circuit breaker)
- Model (e.g., QKB3-80)
- Trip type (e.g., C: C-type tripping curve)
- Pole number (e.g., 2P)
- Rated current (e.g., 63A)
- Quantity (e.g., 100 units)
Order Example
Miniature circuit breaker; QKB3-80/2P/C63A; Quantity: 100 units