Non-isolated LED Drivers lack galvanic isolation between the AC input (primary) side and the DC output (secondary) side to the LEDs. Instead of using a transformer for electrical separation, they employ simpler topologies like buck, boost, or buck-boost converters with a single inductor, directly connecting input and output circuits electrically.
From a safety perspective, this design means the output can carry high-voltage potential relative to ground, increasing the risk of electric shock if users touch exposed terminals or if insulation fails. The absence of a transformer makes LEDs more vulnerable to mains surges, transients, and interference, potentially shortening lifespan or causing failure. Safety compliance relies heavily on the luminaire's overall design: Class I grounding, high-insulation materials, sealed non-conductive enclosures, reinforced voltage protection (e.g., up to 3kV on substrates), and proper installation to prevent direct contact.
Advantages include higher efficiency (often >90-95%), smaller size, lighter weight, lower cost (fewer components), reduced heat, and better energy savings. They suit enclosed, inaccessible, or non-user-contact applications like industrial warehouses, vapor-tight fixtures, sealed outdoor lights, horticultural lighting, and cost-sensitive projects where efficiency outweighs isolation needs.
While not inherently SELV-compliant like isolated types, modern non-isolated drivers incorporate protections (overvoltage, short-circuit, thermal) and meet standards when integrated correctly. They excel in optimized, budget-conscious installations but require careful system-level safety engineering.
