High Intensity Discharge (HID) lamps require some form of control gear (ballasts) to: (1) Provide enough voltage to strike the arc in the lamp. This function may be done with the ballast itself or with a separate electronic ignitor circuit. (2) To control the arc wattage during warm-up and normal operation. In addition ballasts may: (1) Provide a line voltage matching (transformer) function. (2) Provide enhanced lamp wattage control (regulation) with respect to changes in line voltage and/or lamp voltage. (3) Provide dimming or other control interface functions.

Two Coil Reactor

• Constant Wattage Auto-transformer (CWA)
• Peaked Lead Auto-transformer (PLA)
• Auto-Lag (AL)
• Constant Wattage Isolated (CWI)

Three Coil Reactor

• Magnetic Regulator (MR)
• Electro-Reg^® (ER)

1. Linear, non-regulating circuits including reactors and Auto-Lag ballasts that provide for basic lamp operation. With the exception of the self-ballasted lamp, the linear reactor is the most basic form of ballast. Power factor will be in the 40-50% range. A capacitor can be added to get the circuit high power factor (90% or above.) Power factor remains relatively constant throughout the life of the lamp. The linear ballast pro-vides virtually no line voltage regulation, and outages due to the line dips and brown-outs are typical. Ballast losses for reactor ballasts are lowest of magnetic ballast types. The Auto-Lag Ballast is a reactor ballast combined with a step-up or step-down auto-transformer which allows for input voltage.

The Auto-Lag ballast is a single magnetic frame two coil device. (The use of a separate voltagetransformer and a reactor provides the same operational circuit.)

2. The Constant Wattage Auto-transformer (CWA) bal last represents a step up from the Auto-Lag. It is a ballast circuit which uses magnetic saturation to maintain better lamp wattage regulation and improved dip tolerance. A variation of the CWA, called the Peaked Lead Auto Regulator (PLA) is used for metal halide. Another variation, the Constant Wattage Isolated (CWI) is an isolated winding version of the PLA.

3. Three coil circuits that provide superior electrical and lamp performance. The Mag-Reg (MR) and Electro-Reg (ER) ballasts are three coil, isolated winding, high performance ballasts. The input and lamp windings are separated by a third winding which offsets drastic changes in the demands of the lamp on the supply system and maintains lamp stability during supply system variations. This circuit provides the highest degree of lamp operating stability, waveform control, lowest harmonics, and performance consis-tency thru the life of the lamp.

Electro-Reg is an isolated winding ballast system for   Metal Halide. It provides a significant increase in lamp life and color consistency/stability thru lamp life.

HID Ballast Characteristics
Line Current - On some ballast types, the line current as the lamp starts is less than steady state operating current, so that fuses and circuit breaker ratings can be based strictly on the operating current values. For other ballasts, the line starting current may be considerably higher than the steady state operating value, so fuses, circuit breakers, and photoelectric control switches must be sized to accommodate the higher starting current.

Power Factor - To be classes as "high power factor" a ballast must have a power factor of at least 90%. Anything less is considered "Normal Power Factor" or "Low Power Factor." A low power factor ballast makes less efficient use of the distribution system. This requires larger wire sizes, larger switches, circuit breakers, and distribution transformers for the equivalent connected load. Occasionally, as lamps age, lamp operating parameters may change and cause power factor of some high power factor ballasts to fall below 90%. It is important to note that a NPF ballast is no less efficient than an equivalent HPF ballast.

Line Voltage Regulation - This is the change in lamp watts due to line voltage variation. Consideration should be given to the variation in line voltage and feeder voltage drop to be expected on a particular system where HID lamps will be applied to ensure that the regulating capacity of the ballast is matched to the regulation of the power system. A majority of modern power distribution systems are required to operate between ±5% of nominal line voltage, although systems are occasionally encountered which may vary as much as ±10% or more from nominal. Power shortages may result in "brown-outs" in some areas, which can create lamp starting problems especially with those ballasts designed for ±5% operation. In any case, the expected fluctuation in the power system voltage is an important consideration in ballast selection especially where long wiring runs are involved.

Extinction Voltage (Dip Tolerance) - All power systems are subject to dips in the line voltage as loads are switched in and out, or as other transient conditions occur. A good, stiff, well-regulated distribution circuit will seldom see voltage dips of more than 10%, but on some circuits; dips of 20% or more may occur. If the ballast is not capable of "riding through" the voltage dip and sustaining the lamp, the lamp will extinguish and have to cool down before re-ignition. Lamp drop out due to line voltage dips generally increase as lamps age. Ballasts with improved dip tolerance may delay the onset of lamp drop out problems.

Fusing - Most luminaires are offered with a fusing option. In the case of HID lighting, fusing is primarily used to isolate the individual fixture. For example, if an industrial luminaire ballast shorts (draws very high line current) then in all probability the breaker for the entire circuit will trip which will turn off every luminaire on that circuit. If the luminaire is properly fused however, the fuse would clear (open) prior to the tripping of the breaker and the circuit would still be active. This is important where loss of all lighting on a particular circuit is a major problem. The isolation fusing provided may also help in trouble shooting problems on the circuit.

HID Ballast Circuits

208 & 240 Volt for 200-400 watt

480 Volt for 1000 watt

*HPF 90% Plus

HID Ballast Circuits (continued)

120 Volt
200-400watt

HPF 90% Plus

HID Ballast Circuits (continued)

480 volt
for 700 & 1000 watt

HPF 90%
Plus

HPF 90%
Plus

HID Ballast Circuits (continued)

HID Ballast Data — High Pressure Sodium
High-Pressure Sodium ^{3, 4}

HID Ballast Data — High Pressure Sodium
High-Pressure Sodium (continued) ^{3, 4}

60

HID Ballast Data — High Pressure Sodium
High-Pressure Sodium (continued) ^{3, 4}

60

HID Ballast Data — High Pressure Sodium
High-Pressure Sodium (continued) ^{3, 4}

HID Ballast Data — High Pressure Sodium
High-Pressure Sodium (continued) ^{3, 4}

HID Ballast Data — High Pressure Sodium
High-Pressure Sodium (continued) ^{3, 4}

HID Ballast Data — High Pressure Sodium
High-Pressure Sodium (continued) ^{3, 4}

Metal Halide
HID Ballast Electrical Data

Metal Halide
HID Ballast Electrical Data (continued)

Metal Halide
HID Ballast Electrical Data (continued)

Metal Halide
HID Ballast Electrical Data (continued)

Metal Halide
HID Ballast Electrical Data (continued)

Metal Halide
HID Ballast Electrical Data (continued)

Metal Halide
HID Ballast Electrical Data (continued)

Metal Halide
HID Ballast Electrical Data (continued)