What is the difference between Class 2 and SELV

When it comes to electrical systems and safety measures, there are certain classifications and standards that need to be followed. Two common classifications that often come up are "Class 2" and "SELV." It's essential to understand these classifications to ensure proper implementation and usage of electrical equipment. In this article, we will explore the difference between Class 2 and SELV.

Class 2: Defining Safety Limits for Electrical Equipment

Class 2 is a safety standard established to determine the maximum power output and voltage level allowed for electrical devices. This classification ensures protection against electric shock hazards by limiting the energy delivered to the equipment below a certain threshold. The primary objective of Class 2 is to provide a safe operating environment for both users and equipment.

Devices meeting the Class 2 criteria must operate at a maximum power of 100 watts and offer output voltages under 30 volts. Additionally, their power supplies must restrict the current flow to reduce the risk of harm. These limitations make Class 2 suitable for low-power electronics like small appliances, LED lighting, and some electronic toys.

SELV: Protecting from Electric Shock

SELV stands for "Safety Extra Low Voltage" and focuses on preventing electric shock hazards by maintaining extremely low voltage levels. Unlike Class 2, which limits both power and voltage, SELV exclusively concentrates on voltage levels. The purpose of SELV is to minimize the risks associated with accidental human contact with live parts.

According to international standards, SELV classifies voltage levels below 60 volts DC or 25 volts AC as extra-low voltage. To comply with SELV regulations, electrical systems must implement additional safety measures such as insulation barriers, protective separation, or reinforced insulation. Common examples of SELV-compliant devices include mobile phone chargers, computer peripherals, and medical equipment.

Differentiating between Class 2 and SELV

The key distinction between Class 2 and SELV lies in their objectives and approach to safety. Class 2 limits the power and voltage while SELV only focuses on voltage. Class 2 ensures protection against electric shock by restricting both energy delivery and voltage levels, making it suitable for low-power electronics. On the other hand, SELV addresses electrical safety concerns by emphasizing extremely low voltage levels, mitigating the risk of accidental human contact with live parts.

In summary, understanding the difference between Class 2 and SELV is crucial for electrical design and equipment selection. While Class 2 restricts power output and voltage, SELV exclusively concentrates on minimizing voltage levels for enhanced safety. Complying with these classifications ensures safer usage and provides a clear framework for manufacturers, designers, and users when dealing with electrical systems.