The market for magnetic (core and coil) ballasts is shrinking! The National Appliance Energy Conservation Amendment of 1988, Public Law 100-357 prohibited manufacturers from producing ballasts having a power factor of less than 90%.

Ballasts that meet or exceed the federal standards for energy savings are marked with a letter “E” in a circle. Dimming ballasts and ballasts designed specifically for residential use were exempted.

Today’s electronic ballasts are much lighter in weight and considerably more energy efficient than older style magnetic ballasts (core and coil). Energy saving ballasts might cost more initially, but the payback is in the energy consumption saving over time.

Old-style fluorescent ballasts get very warm and might consume 14 to 16 watts, whereas an electronic ballast might consume 8 to 10 watts. Combined with energy-saving fluorescent lamps that use 32 or 34 watts instead of 40 watts, energy savings are considerable. You are buying light, not heat.

When installing fluorescent luminaires, check the label on the ballast that shows the actual volt amperes that the ballast and lamp will draw in combination. Do not attempt to use lamp wattage only when making load calculations because this could lead to an overloaded branch circuit.

For example, a high-efficiency ballast might draw a total of 42 volt-amperes, whereas an old-style magnetic ballast might draw 102 voltamperes.

The higher the power factor rating of a ballast, the more energy efficient. Look for a power factor rating in the mid to high 90s.

Various line currents, volt-amperes, wattages, and overall power factor for various single-lamp
fluorescent ballasts.

Ballast Line Current Line Voltage Line Volt-Amperes Lamp Wattage Line Power Factor
No. 1   0.35                120                              42                    40                    0.95(95%)
No. 2   0.45                120                              54                    40                    0.74(74%)
No. 3   0.55                120                              66                    40                    0.61(61%)
No. 4   0.85                120                              102                  40                    0.39(39%)
No. 5   0.22                120/277                       26                    30                    0.99(99%)


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