Thermal Breakers

Thermal breakers protect circuits from excess current in a similar way to a fuse, however, they often feature a switch allowing them to be reset if tripped. While fuses simply burn out and have to be replaced, circuit breakers can just be reset. This offers more sophisticated protection against overcurrent, with cost savings for businesses in the long run. Common types of thermal breakers include thermal magnetic circuit breakers and thermal automotive circuit breakers.

Functions of Thermal Circuit Breakers

Thermal circuit breakers serve multiple crucial functions:

**Overcurrent Protection: **This is the primary function of thermal circuit breakers. When the current flowing through the circuit exceeds the breaker's rated value, the circuit breaker is activated and it trips, interrupting the current flow. This helps prevent damage to wires, components, and equipment.

**Fire Prevention: **Overloaded circuits can generate excessive heat, potentially leading to fires. By quickly interrupting excessive current flow, thermal circuit breakers help prevent overheating and electrical fires, particularly in older buildings or sites with outdated wiring.

**Safety: **If a fault occurs in the wiring or a connected appliance, the circuit breaker will trip, disconnecting the circuit and preventing potential electrocution hazards to workers or others on site.

**Compliance: **In Singapore, as in many other countries, electrical codes and regulations often mandate the use of thermal circuit breakers to ensure safety compliance with local laws on PAT testing.

Types of Thermal Circuit Breakers

Thermal Magnetic Circuit Breakers

Thermal magnetic circuit breakers, also known as thermal magnetic MCCBs, combine two protection mechanisms: a thermal element (bimetallic strip) for overload protection and a magnetic element for instantaneous trip in case of short circuits. MCCBs also often incorporate a magnetic element for instantaneous trip in case of short circuits, providing rapid protection against potentially dangerous high currents.

The thermal aspect of this type of circuit breaker allows for smaller overcurrents over a longer period of time, but will quickly trip the circuit for larger overcurrents. This is useful in the case of motors, as there will be a small overcurrent each time the engine is switched on for a short length of time, which should not trip the circuit. These breakers are commonly used in distribution boards and industrial applications, and make up part of the subsidiary circuits in the broader electrical supply system to protect against overcurrent.

Thermal Automotive Circuit Breakers

Automotive thermal circuit breakers are specifically designed for use in most types of vehicles, offering protection against overcurrent and short circuits in the unique electrical system found in cars, vans, buses, and boats. They are engineered to handle the specific demands of automotive environments, such as voltage fluctuations, vibrations, and temperature extremes. This makes them key to the reliable operation of various electrical components in vehicles, including lighting, air conditioning, and entertainment systems.

Common Pole Numbers for Thermal Circuit Breakers

Thermal circuit breakers are available with different pole numbers, indicating the number of circuits they can protect:

1 Pole or Single Pole

Single-pole thermal circuit breakers protect one live wire and are commonly used as residential circuit breakers for lighting and small appliance circuits. Push-to-reset thermal circuit breakers often fall under this category.

2 Pole or Double Pole

Double-pole thermal circuit breakers protect two live wires and are used in applications requiring the simultaneous disconnection of both live conductors. This is common in 240V circuits or appliances that require two live wires for operation.

3 Pole or Triple Pole

Triple-pole thermal circuit breakers protect three live wires and are typically used in three-phase power systems for industrial applications.

Industry Applications of Thermal Circuit Breakers

** **The versatility of thermal circuit breakers makes them essential components in various industries in Singapore:

• **Residential: **They protect wiring and appliances from overloads and short circuits in homes, ensuring safety and preventing electrical fires.
• **Commercial: **They safeguard electrical systems in commercial buildings like offices, shops, and restaurants, preventing disruptions and ensuring the safety of occupants.
• **Industrial: **Thermal magnetic circuit breakers are widely used in industrial settings to protect machinery, motors, and control panels from overcurrent and short circuits, ensuring continuous operation and preventing costly downtime.
• **Automotive: **Automotive thermal circuit breakers are crucial for protecting electrical circuits and components in vehicles, ensuring reliable operation and passenger safety.
• **Renewable Energy: **They play a vital role in protecting solar panel installations and wind turbine systems from electrical faults, ensuring the longevity and efficiency of these renewable energy sources.

Leading Supplier and Distributor of Thermal Circuit Breakers

RS is a trusted supplier, distributor, and manufacturer of thermal circuit breakers in Singapore, offering a wide range of products from reputable brands like Altech, Schneider Electric, Sensata/Airpax, and our own RS PRO line. Whether you need a thermal magnetic breaker or a thermal switch circuit breaker, we have the right solution for your industrial needs.

Order your thermal circuit breakers online today and enjoy fast delivery across Singapore. Next-day delivery and self-collection options are also available. For more details on our ordering process, delivery services, and delivery fees, please refer to our Ordering Page and Delivery Page.