| Product Type | Thermal Magnetic Circuit-Breaker (MCB) |
| Manufacturer | Legrand |
| Model Series | DX3 |
| Reference Number | 409069 |
| EAN Code | 3245064090698 |
| Number of Poles | 4 poles (3 phase + neutral) |
| Rated Current | 40 Amperes |
| Rated Voltage | 400 Volts AC |
| Rated Insulation Voltage | 500 Volts |
| Rated Impulse Withstand Voltage | 4 kV |
| Breaking Capacity at 230V | 16 kA (Icn) / 32 kA (Icu) |
| Breaking Capacity at 400V | 10 kA (Icn) / 16 kA (Icu) |
| Release Characteristic | B curve (tripping threshold 120A-200A or 3-5 In) |
| Current Limiting Class | Class 3 (maximum energy limitation) |
| Frequency Range | 50-60 Hz |
| Degree of Protection | IP20 (fingerproof against solid bodies >12.5mm) |
| Degree of Impact Strength | IK02 |
| Mounting Method | DIN rail mounting with dual clamps |
| Built-in Depth | 44 mm |
| Width | 70.8 mm (4 modular spacing units) |
| Height | 94.8 mm |
| Total Depth | 77.8 mm |
| Connection Type | Screwed terminal |
| Connectable Conductor Cross Section (Multi-wired) | 1.5-25 mm² |
| Connectable Conductor Cross Section (Solid-core) | 1.5-35 mm² (aluminum with accessory 4063-10) |
| Supply Methods | Copper cable, prong busbar (top/bottom), fork busbar (bottom), Legrand HX3 plug busbar (top) |
| Concurrent Neutral Conductor Switching | Yes |
| Flush-mounted Installation | Yes |
| Pollution Degree | 2 |
| Ambient Operating Temperature | -25°C to +70°C |
| Storage Temperature | -40°C to +70°C |
| Color | Grey |
| RAL Number | 7035 |
| Halogen Free | Yes |
| Additional Equipment Possible | Yes (auxiliaries, RCD add-on modules, accessories) |
| Explosion-proof | No |
| Label Space/Information Surface | Yes (integrated label holder) |
| Standards Compliance | IEC 60898-1, IEC/EN 60529, IEC 60947-2, RoHS Directive, REACH Regulation |
| Product Carbon Footprint (Manufacturing) | 3.757 kg CO₂ eq. |
| Warranty | Legrand standard product warranty (subject to proper installation and use) |