Safety Extra-Low Voltage (SELV): What does it mean?

As the name suggests a SELV system is an extra-low voltage electrical circuit. Devices and systems designed to comply with SELV standards must meet specific safety requirements to ensure that the voltage level remains below the designated threshold, even under fault conditions. This ensures that even if a fault occurs, the voltage applied to exposed conductive parts or human contact remains at a safe level to prevent harm.

Where is it used?

SELV is commonly used in various applications, such as low-voltage lighting systems, electronic devices, and telecommunications equipment, where safety is a paramount concern. Within lighting systems and luminaries, you will often see SELV implemented when the operation of an electrical lighting system poses a hazard, e.g., around swimming pools or amusement parks. By adhering to the SELV standard, the risk of electrical accidents is significantly reduced, making it an essential aspect of electrical design and implementation.

What does this mean when it is applied to LED drivers?

SELV is implemented as a safety standard in some LED drivers. By ensuring that the output voltage always stays below the defined voltage value with SELV, a flexible luminaire design with increased safety is possible.

The SELV circuit within a LED driver will have no direct connection to the primary power source and thus is electrically separated from other higher-voltage circuits. The SELV circuit will be instead powered via a transformer or an equivalent isolation device. Because the SELV system is detached from the earth, it will be unable to trigger an electrical shock to users upon contact. The specific voltage threshold for SELV can vary depending on the region and standards being followed, but it typically ranges from 12 to 120 volts AC or 54 volts DC.

Why is this beneficial?

SELV LED drivers are one of the safest electrical systems, owing to their combination of protective separation, low voltage, and basic insulation. Because SELV is a secondary circuit, voltages cannot exceed a safe value. In doing so it reduces risks of electric shock and minimises the potential for fire hazards.

What specifications allow a LED driver to be classified as SELV?

• No live conductor is connected to the Earth.
• The system will be physically distanced from any other system conductors.
• The low-voltage system will not have contact with the extra-low-voltage source. Common sources include output from an isolating transformer, batteries, a motor-generator set, or a power supply unit that does not have any low voltage at its output terminals.
• Any higher voltage circuits are separated from the SELV circuit.
• Exposed-conductive parts of SELV-supplied equipment will not be connected to any other exposed conductive parts, to earth, or to extraneous-conductive parts.

What are the products?

A flexible range of SELV LED drivers, producing a high quality of light with very low ripple. Offering a long-lasting and reliable power supply with increased safety benefits from the SELV technology. Available in multiple output current and varying compact and linear sizes.

• IT-FIT-60/220-240/1A2-CS-L
• IT-FIT-40/220-240/800-CS-L
• IT-FIT-18/220-240/350-CS-L
• IT-FIT-15/220-240/700-CS-I
• IT-FIT-4/220-240/400-CS-I

There are many other Inventronics OSRAM SELV LED Drivers available. To find more take a look at our product selector tool here.

About Inventronics

NB: In May 2023, OSRAM sold it's LED Drivers, Lighting Controls, LED Flex and LED Modules business to Inventronics. These products continue to be branded OSRAM but are now owned, designed, manufactured and developed by Inventronics.