MCB
MCBs: modular circuit protection against overloads and short circuits.
- Function: thermal protection against overloads and magnetic protection against short circuits.
- Formats: 1P, 1P+N, 2P, 3P and 4P depending on the range.
- Selection: choose the breaking capacity and current rating according to the circuit.
- Use: lighting, sockets, machinery auxiliaries and distribution boards.
Miniature circuit breakers: poles, rated current and breaking capacity
Solera miniature circuit breakers (MCBs) protect low-voltage circuits against overloads and short circuits through thermal and magnetic tripping. They are used in residential, office, commercial and distribution boards, with a suitable reference selected for each circuit. In the S24 6 kA and 10 kA ranges, breaking capacity, pole configuration, rated current and occupied space are separate selection criteria.
Comparing the S24 6 kA and 10 kA ranges
| Range | Breaking capacity | Verified configurations | Format differences |
|---|---|---|---|
| S24 6 kA | 6 kA | 1P, 1P+N, 2P, 3P and 4P | 1P+N in 1 or 2 modules, depending on reference |
| S24 10 kA | 10 kA | 2P, 3P and 4P | 2P in 2 or 3 modules; 4P in 4 or 6 modules, depending on reference |
Selection criteria for the distribution board
Rated current, expressed in A, must suit the load and conductor protection. Breaking capacity, expressed in kA, must be appropriate for the prospective short-circuit current at the installation point, taking account of the declared voltage and conditions. A residential, commercial or industrial setting alone does not determine whether 6 kA or 10 kA is required.
Also check the network arrangement, protected and switched poles, trip curve, rated voltage, available modules and permitted connections. Curve C is documented for the S24 6 kA references reviewed and the S24MG 6–63 A variants; check the specific documentation for other variants. DIN-rail mounting does not establish universal compatibility with busbars or accessories.
Frequently asked questions
Do amperes and kiloamperes describe the same rating?
No. For example, 16 A identifies the rated current, while 6 kA or 10 kA states the declared short-circuit breaking capacity. Both ratings must be appropriate for the circuit.
Can a 1P+N device be replaced by a 2P device of the same width?
Do not assume equivalence. Check which poles each reference protects and disconnects, its neutral arrangement, voltage and the circuit configuration. Modular width alone does not establish interchangeability.
Does an MCB replace a residual current device or surge protector?
No. Overload and short-circuit protection differs from residual current detection and surge protection. Where a combined device is required, explicitly check which protective functions it incorporates.