SELV, which stands for Safety Extra Low Voltage , refers to a safety standard for electrical systems operating at low voltage. The idea behind SELV is to minimize the risk of electric shock, thus ensuring human safety.
A SELV system has the following characteristics:
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Voltage : The system operates at a voltage of up to 50 volts alternating current (AC) or 120 volts direct current (DC) , which is significantly lower than the standard mains voltage (230V AC in many countries).
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Insulation : SELV systems are well insulated, so there is no direct connection to earth or other parts of the electrical system that could pose an electric shock hazard. This means that even if a fault occurs (for example, a malfunction in the appliance), the risk of electric shock to the user is low.
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Safety : Because the voltage is so low, the risk of serious electric shock is minimal, even if someone accidentally comes into contact with the wiring or the device. This makes SELV ideal for applications where safety is paramount, such as bathrooms, outdoor lighting, and other situations where people could come into contact with the system.
Applications of SELV:
- LED Lighting : Many LED lamps and lighting systems operate on SELV, making them safer for use in humid environments such as bathrooms or outdoor applications.
- Device Charging Stations : Electronic devices that operate on low voltage can also use SELV to ensure user safety.
- Security systems : Such as alarm systems, which often operate at a safe low voltage to avoid the risk of electric shock.
In summary, SELV is a measure to make electrical systems safer by limiting them to a low, safe voltage, with additional insulation and protection against electrical hazards.