Introduction

The invention protects class II outdoor led luminaires against overvoltages in differential and common modes. This technology can be applied to all Class II luminaries designed for outdoor lighting. The insulation class of the equipment is not downgraded from Class II in Class I with great advantages in terms of the protection against electric shock.

Technical features

The Invention protects electronic components of outdoor led luminaries in Class II against LigthningOvervoltages (LO) in common or differential mode.

For Class I equipment, protection against LO is achieved by inserting SPDs, Surge Protection Devices, between the active conductors (differential protection) and between the active conductors and the earth terminal (common mode protection). For Class II equipment, where earth terminal is missing, this approach is not allowed. The invention exploits the geometry of LED lamps to make a capacitor, by inserting an insulating sheet between the metal heatsink and the external case.

Under normal operating conditions, the capacitance behaves like an open circuit. When an OL occurs, its impedance decreases, allowing the lightning current to flow into the ground. In this way, the protection against overvoltages is guaranteed and Class II insulation is preserved.

Possible Applications

• Infrastructures: streets and railways;
• Industrial sites;
• Commercial sites;
• Car parks;
• Public gardens;
• Airports;
• Ports.

Advantages

• Protection of electronic devices against overvoltages;
• Compliant with current Standards for the protection against electric shock;
• Easy to be applied;
• Small increase in overall dimensions;
• Suitable for the modification of existing lamps;
• Low cost.