PHILIPS ELECTRONICS -LIGHT 503391 Fluorescent Ballast Electromagnetic, Conventional, Encapsulated 2 Lamps T12 Lamps 120 V,

Each ballast is designed to operate at the nominal voltage shown on the Philips Advance ballast label. Abnormal deviation from these values will result in damage to either the ballast or lamp or both. It is therefore necessary that the voltage applied to ballasts be maintained within the respective limits shown in the adjoining table.A ballast subjected to higher than nominal voltages will typically operate at increased temperatures. This will result in reduced ballast life. Low voltage can cause premature lamp failures as well as unreliable lamp starting.All ballasts are designed for single frequency operation. Therefore, best results will be obtained when that ballast is used on the frequency shown on the ballast label.