Dimming
Warranty policy on the dimming of Venture Lighting International metal halide lamps:

WARRANTY POLICY: Venture Lighting International, Inc. provides a one-year warranty on lamp life for lamps operated on dimmable ballasts provided the following conditions are met:

1) A lamp must not be started in the dimmed operating mode.

2) The lamp must warm up and attain full wattage for at least 15 minutes (20 minutes for lamp wattages greater than 450 watts) before dimming can commence.

3) Operating position requirements:
Note: See individual Lamp Data Sheets for minimum dimmed wattage levels.
a) Pulse start lamps - Dimmable in all published lamp orientations.
b) Probe start lamps - Dimmable only in the base up (±15°) orientation.
c) SPC, Ceramic MR16, T4 and T6 lamps (20 - 150 watt) cannot be dimmed. SPC, Ceramic T6C (60, 90, 140 watt) and T12 (210 and 315 watt) are dimmable to 50% lamp power.

4) The reduced wattage level for a metal halide lamp must be achieved with a ballast which meets the recommended ANSI specifications for starting and operating an ANSI reference lamp at the rated lamp power. Magnetic and electronic ballasts should not lower the lamp wattage below the Venture specified dimming level (see Specification sheets) when using a reference lamp at
• 90% of the rated line voltage for CWA/CWI and electronic ballasts
• 95% of the rated line voltage for Lag (HX & Reactor) ballasts.

5) System Requirements
a) CWA/CWI Switched Capacitor Dimming
• The sustaining voltage of the ballast in the minimum dimmed mode must be maintained at a high enough level to sustain lamps throughout life.
b) Electronic Ballast Dimming
• The ballast must be capable of sustaining lamps throughout the rated lamp life in both the full and dimmed wattage modes.
• To reduce cycling as lamps age, it is recommended that the time for reduction in lamp wattage from 100% to the minimum dimmed level be no shorter than 60 seconds.
c) Line Voltage Dimming (Venture magnetic ballasts, only)
• Line voltage dimming must be accomplished by voltage reduction only, not by waveform chopping, i.e. phase control.
• To reduce cycling problems as lamps age, it is recommended that the time for reduction in line voltage from 100% to the minimum specified level (see below) be no shorter than 60 seconds.
• For CWA/CWI ballasts line voltage must not drop below 70% of the rated ballast input voltage
• For Lag (HX lag and Reactor) ballasts line voltage must not drop below 85% of rated ballast input voltage.