This 40A circuit breaker (MCB) is mainly used to protect supply cables: for example, the cable from the main consumer unit to a sub-board in a garage, workshop or garden shed. Both poles are protected, so it can also be used in a 3×230 V network, where both conductors are phase conductors.
When do you choose 40 A?
- supplying a sub-distribution board with its own MCBs
- a heavy single-phase load for which the manufacturer specifies 40 A
- an outbuilding or workshop with several circuits
According to the table for homes in AREI (the Belgian electrical installation regulations), 40 A requires at least 6 mm²; over longer distances, electricians often choose 10 mm². Your electrician will also check whether your supply and the upstream protection can handle that load.
Benefits
- energy limiting class 3: low let-through energy in the event of a short circuit, which spares the cable and the upstream protection
- back-up fuse up to 80 A gG permitted
- twin terminals on both sides, for conductors up to 25 mm²
- IP20, IP40 with cover
Connection
For a supply cable, terminal capacity matters: the BMS4 terminals accept conductors up to 25 mm². The supply can come in from the top or the bottom, and it can be mounted in any orientation. Strip no more than 12 mm of insulation so that no bare copper protrudes from the terminal.
Good to know
A sub-board must itself also comply with AREI, with its own MCBs and the required residual current protection. Leave this work to a qualified electrician. If you extend your installation, you must then have it inspected again by an approved inspection body.
| Product code | BM417240 (Schrack BMS4 C 40/2) |
|---|---|
| EAN | 9004840390506 |
| Rated current | 40 A |
| Tripping curve | C |
| Poles | 2P, both poles protected |
| Breaking capacity | 4.5 kA (EN 60898-1), 6 kA (EN 60947-2) |
| Rated voltage | 230/400 V AC, 50/60 Hz |
| Width | 2 modules (approx. 35 mm) |
| Terminal capacity | 1 to 25 mm² |
| Power loss | 7.5 W |
| Max. back-up fuse | 80 A gG |
| Degree of protection | IP20, IP40 with cover |
| Ambient temperature | -5 °C to +40 °C (calibrated at 30 °C) |
| Standards | EN 60898-1, EN 60947-2 |
| Reference | 9004840390506 |
| Category | Circuit breakers and RCDs |
| Merk | Schrack |
| Weight | 0.24 kg |
Shipping with GLS
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