A Class 2 circuit is typically a low-energy and low-voltage circuit, and while a circuit breaker protects electrical circuits from overcurrent, the term "Class 2 circuit breaker" is not a standard term. Instead, Class 2 circuits themselves are protected by other means, such as fuses, or inherent design limitations. The characteristic of being a Class 2 circuit lies in its energy limitations, not in having a specific type of circuit breaker.
Here's a breakdown of what defines a Class 2 circuit:
- Low Energy: Generally limited to 100VA (Volt-Amps). This means the power output is relatively low, reducing the risk of electrical shock and fire.
- Low Voltage: Usually capped at 30V (Volts) AC or 60V DC. This low voltage further minimizes the risk of electrical hazards.
Because Class 2 circuits are inherently low energy, standard circuit breakers are typically not required for protection. Standard circuit breakers are designed to protect against high current faults. Instead, other protection methods are often employed:
- Fuses: Small fuses can provide overcurrent protection for Class 2 circuits.
- Current Limiting Power Supplies: These supplies are designed to limit the current output to safe levels, eliminating the need for external protection.
- Inherent Design: The circuit's design may limit the available current to a safe level.
Examples of Class 2 Circuits:
- Low-energy voice and sound systems
- Intercom systems
- Public address systems
- Low-voltage lighting
- Programmable Logic Controllers (PLCs)
- Security systems
- Thermostats
Key Takeaway: The term "Class 2 circuit breaker" is not a standard industry term. Class 2 circuits are defined by their low-energy and low-voltage characteristics, and these circuits are protected using methods appropriate for their low-energy nature (fuses, current limiting power supplies, or inherent design limitations), rather than standard circuit breakers.
