Magnetic Circuit Breaker
A magnetic circuit breaker is a safety device designed to interrupt an electrical current in the event of a power surge, protecting electrical equipment and circuitry from damage. Unlike fuses that burn out and require replacement, magnetic circuit breakers use an electromagnet (solenoid) to generate a magnetic field, which is employed to measure the strength of the current. Here’s how it works:
- Detection of Current Strength:
- The circuit breaker uses a solenoid to generate a magnetic field.
- As the electric current flows through the circuit, the solenoid’s magnetic field strength increases.
- Mechanical Trip Mechanism:
- The magnetic circuit breaker has a preset limit or rating for the maximum current it can allow.
- When the current exceeds this limit, the increased magnetic field becomes strong enough to overcome the spring tension holding a metallic lever.
- Tripping of the Breaker:
- The metallic lever is released, causing the circuit breaker to trip.
- The contact points move apart, breaking the circuit and preventing further flow of current.
- Immediate Reset:
- After tripping, the circuit breaker can be reset immediately.
- Resetting the breaker brings the contact points back together, restoring the circuit.
- Protection Against Overheating:
- Some magnetic circuit breakers also incorporate a thermal element for protection against prolonged low-level surges.
- If the circuit or equipment overheats, the thermal element causes the breaker to trip.
The immediate reset capability is a significant advantage of magnetic circuit breakers, allowing for quick restoration of power without the need for replacement parts. These breakers effectively protect against short circuits and large power surges. However, for prolonged low-level surges, additional measures, such as thermal elements, are used to prevent overheating and potential damage.