LED power class refers to the output voltage and power capabilities of AC-DC power supplies (also known as LED drivers), categorized under IEC (International Electrotechnical Commission) standards. These classes (Class I, Class II, and Class III) denote the power supply's internal construction and the level of electrical insulation provided.
Here's a breakdown:
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Classification Origin: The classifications stem from IEC (International Electrotechnical Commission) safety standards related to electrical shock protection.
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Core Meaning: Primarily, it identifies how the power supply is insulated and how it prevents electric shock hazards. It also impacts the grounding requirements of the LED fixture.
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Why it matters: Understanding these classes is crucial for selecting the appropriate LED driver for safety and compliance, ensuring the end product meets regulatory requirements.
Let's examine the specific classes:
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Class I:
- Insulation: Employs basic insulation, and relies on grounding (earthing) for safety.
- Protection: Requires a protective earth (ground) connection to prevent electric shock in case of a failure of the basic insulation.
- Grounding: Must be grounded.
- Application: Often found in applications where higher power is needed.
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Class II:
- Insulation: Features double or reinforced insulation.
- Protection: No reliance on grounding for safety. Designed so that a single failure will not result in dangerous voltage becoming exposed.
- Grounding: Does not require grounding.
- Application: Common in household appliances and smaller LED fixtures where double insulation provides adequate protection.
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Class III:
- Insulation: Operates at a Safe Extra Low Voltage (SELV), typically below 50V AC or 75V DC.
- Protection: Inherently safe due to the low voltage levels.
- Grounding: Grounding is typically not required.
- Application: Used in low-voltage LED lighting systems and portable devices. Examples include some LED strip lighting.
In summary, the LED power class defines the safety features and grounding requirements of the LED driver, significantly impacting the overall safety and installation requirements of the LED lighting system. Selecting the correct class is important for compliance, performance, and user safety.
