PRG DMX Reference Guide 5.4 - Manual (Page 60)

52 DMX512 REFERENCE GUIDE
EQUIPMENT HANDLING
Lamps
Servicing
+ When handling a lamp, hold it by the ceramic base while wearing cotton gloves or finger cots. Do not touch the
glass envelope (bulb). If you touch the glass with bare fingers, wipe off any fingerprints with alcohol.
+ Use care when opening and closing the rear door of the VL2B and VL2C luminaires. Any jarring of the rear door
can undo the optical alignment of the lamp.
Heat
+ When lamps are lit, the interior of the luminaires becomes very hot. To aid in the airflow circulation within the
luminaires, after dousing the lamps, wait ten minutes before removing power to the luminaires. This will provide
enough time for the equipment fan to cool off the unit.
Lamp Life
+ When operating arc lamps, allow luminaires to operate for at least 3 minutes. It takes about 3 minutes for the fill
components (mercury and halogen-metal compounds) in the lamp tubes to vaporize completely. If the lamps are
switched off earlier than 3 minutes, the fill components are partially vaporized. The inadequately vaporized fill
components and the electrode material (tungsten) are deposited in the areas of the lamp tubes that have
remained cool. As a result, the lamp tubes blacken prematurely and reduce the service lives of the lamps.
+ If system will be unattended for more than two hours, luminaire lamps should be doused. Standby mode should
not be used for more than two hours.
+ For VL6 luminaires, if lamp is struck, the luminaire should be maintained in a horizontal position when not in use.
+ For arc lamp luminaires, heads should be tilted horizontal before starting lamps. Lamps generate light by an
electrical discharge arc, whereby the electrons from two electrodes excite the fill components to give off light.
Because of the alternating current "position", the electrons are alternately given off by the two electrodes. When a
lamp is set in a vertical position, the halogen-metal compounds, which determine the color temperature of the
lamp, collect at the top end of the glass envelope. When the lamp is started, color deviations occur since the
concentration of halogen compounds is greater around the top electrode than the bottom electrode. In addition,
the fill components that are difficult to vaporize congeal around the bottom electrode, thereby reducing lamp life.