Lighting Inverters Information
Lighting inverters provide alternating current (AC) power for indoor, outdoor and emergency lighting, signage, and associated controls. They are used in conjunction with power supplies and power conditioners, and provide permanent lighting for public areas such as staircases, public bathrooms, and parking garages. Lighting inverters are also used to illuminate exit signs in schools and buildings, and to simplify maintenance tasks and monthly monitoring. Products with voltage regulation can supply multiple floors and support greater distances because of the feed wire’s minimal voltage drop. Product specifications for lighting inverters include volt-ampere (VA) rating, lighting type, and approvals such as the UL Mark from Underwriters Laboratory (UL). Product features include time-delayed switched power, time-delayed return power, and continuous duty.
Lighting inverters are used with various types of lighting fixtures and lamps. Examples include incandescent, fluorescent, and high intensity discharge (HID). Incandescent lamps generate light by passing an electric current through a thin filament wire (usually of tungsten) until the wire is extremely hot. Fluorescent lamps are high-efficiency lamps that use electrical discharge through low-pressure mercury vapor to produce ultraviolet (UV) energy, which is then transformed into visible light. High-intensity discharge or HID lamps contain compact arc tubes, which enclose various gases and metal salts, operating at relatively high pressures and temperatures. Lighting inverters for high-pressure sodium (HPS), mercury vapor, and metal halide lamps are also available.
Lighting inverters can provide permanent no-break power (normally on) and switched power (normally off). Permanent no-break power provides uninterrupted service and is designed for permanent lighting in public locations such as stairwells and bathrooms. Normally, lighting inverters with no-break power are used with high-intensity discharge (HID), high-pressure sodium (HPS), mercury vapor, and metal halide lamps. Switched power is activated only when there is a power outage. Typically, signage and additional lighting is connected to this function. In applications where some general lighting is also used as emergency lighting, lighting inverters may automatically override the circuit and supply power directly to the emergency lamps. Typically, this configuration requires an additional wire from the lighting inverter to bypass the local control device.