Application Scope
The QKM1 series molded case circuit breakers (MCCBs) (hereinafter referred to as “breakers”) have a rated insulation voltage of 800V (660V for QKM1-63). They are suitable for AC 50Hz/60Hz circuits with a rated working voltage of 400V and rated working currents from 10A to 800A, for infrequent switching of power lines and non-frequent starting of motors.
The breakers provide overload, short-circuit, and undervoltage protection to safeguard lines and power equipment from damage.
Based on their rated ultimate short-circuit breaking capacity, the breakers are divided into two types:
- L type: Standard breaking capacity
- M type: High breaking capacity
Key features include:
- Compact size, high breaking capacity, short arc flash distance, and low vibration
- Can be installed vertically (front mounting) or horizontally (side mounting)
- Equipped with isolation function
This product complies with GB/T 14048.2 Low-voltage switchgear and controlgear – Part 2: Circuit breakers.
Model Selection Guide
| Code Segment | Definition | Options & Specifications |
|---|---|---|
| QKM1 | Product Code | Molded case circuit breaker |
| □ | Frame Grade Rated Current (Inm) | 63, 125, 250, 400, 630, 800 |
| □ | Breaking Capacity Level | L: Standard typeM: High breaking type |
| □ | Operation Mode | None: Direct handle operationP: Motor operationZ: Rotary handle operation |
| □ | Pole Number | 2: 2-pole3: 3-pole3N: 3-pole + neutral4: 4-pole |
| □ | Trip Mode & Accessory Code | Refer to Table 1 |
| □ | Application Code | None: General power distribution2: Motor protection |
| □ | N-pole Type (4-pole only) | Refer to notes below |
| □ | Derivative Code | None: Standard productT: Transparent cover product |
| □ | Rated Current (In) | Refer to Table 2 |
| □ | Accessory Control Voltage | – |
| □ | Installation Mode | None: Fixed front mountingB: Fixed rear mountingC: Plug-in rear mounting (must be specified) |
Notes
- 4-pole breaker N-pole types (default: Type B):
- Type A: N-pole without overcurrent release, always closed, and does not trip with the other three poles.
- Type B: N-pole without overcurrent release, trips together with the other three poles (N-pole closes after the other poles).
- 2-pole breakers are only available in frame grades QKM1-125 and QKM1-250.
Technical Specifications Table
| Product & Model | Frame Grade Rated Current (Inm) (A) | Rated Ultimate Short-Circuit Breaking Capacity (Icu) (kA) | Rated Operational Short-Circuit Breaking Capacity (Ics) (kA) | Rated Current (In) (A) | Rated Working Voltage (Ue) (V) | Rated Insulation Voltage (Ui) (V) | Rated Impulse Withstand Voltage (Uimp) (kV) |
|---|---|---|---|---|---|---|---|
| QKM1-63L | 63 | 25 | 18 | 10, 16, 20, 25, 32, 40, 50, 63 | 380 | 660 | 8 |
| QKM1-63M | 63 | 50 | 35 | 10, 16, 20, 25, 32, 40, 50, 63 | 380 | 660 | 8 |
| QKM1-125L | 120 | 35 | 22 | 16, 20, 25, 32, 40, 50, 63, 80, 100, 125 | 400 | 800 | 8 |
| QKM1-125M | 120 | 50 | 35 | 16, 20, 25, 32, 40, 50, 63, 80, 100, 125 | 400 | 800 | 8 |
| QKM1-250L | 250 | 35 | 25 | 100, 125, 140, 160, 180, 200, 225, 250 | 400 | 800 | 8 |
| QKM1-250M | 250 | 50 | 35 | 100, 125, 140, 160, 180, 200, 225, 250 | 400 | 800 | 8 |
| QKM1-400L | 400 | 35 | 35 | 225, 250, 315, 350, 400 | 400 | 800 | 8 |
| QKM1-400M | 400 | 65 | 42 | 225, 250, 315, 350, 400 | 400 | 800 | 8 |
| QKM1-630L | 630 | 50 | 35 | 400, 500, 630 | 400 | 800 | 8 |
| QKM1-630M | 630 | 65 | 50 | 400, 500, 630 | 400 | 800 | 8 |
| QKM1-800M | 800 | 65 | 50 | 400, 500, 630, 700, 800 | 400 | 800 | 8 |
Dimensions & Mounting Dimensions
| Model & Specification | Dimensions (mm) | Mounting Dimensions (Front) (mm) | |||||
|---|---|---|---|---|---|---|---|
| L | W (3P) | W (4P) | H | H1 | W1 | L1 | |
| QKM1-63L | 135 | 78 | – | 90.5 | 73.5 | 25 | 117 |
| QKM1-63M | 135 | 78 | 103 | 98.5 | 81.5 | 25 | 117 |
| QKM1-125L | 150 | 92 | – | 86 | 68 | 30 | 129 |
| QKM1-125M | 150 | 92 | 140 | 104 | 86 | 30 | 129 |
| QKM1-250L | 165 | 107 | – | 110 | 86 | 35 | 126 |
| QKM1-250M | 165 | 107 | 122 | 127 | 103 | 35 | 126 |
| QKM1-400L | 257 | 150 | – | 155 | 106.5 | 44 | 294 |
| QKM1-400M | 257 | 150 | 198 | 155 | 106.5 | 44 | 294 |
| QKM1-630L | 270 | 182 | – | 160 | 110 | 58 | 200 |
| QKM1-630M | 270 | 182 | 240 | 160 | 110 | 58 | 200 |
| QKM1-800M | 280 | 210 | 240 | 155 | 115.5 | 70 | 243 |
Ordering Instructions
Orders must be placed with complete configuration information, following the format:
Product Name + Model & Specification + Quantity
Order Example
Molded case circuit breaker; QKM1-250L/3310/AC230V/250A; Quantity: 100 units.