Industry Relations & Standards
Document No.:
Revision No.:
Issue Date:
DQ4-144-067
E
09-08-2006
Subject: Warning – Metal Halide Display/Optic Lamps [HMI, HMD, HMP, HSD, HSR, HTI, HCD]
Please verify that you have the latest revision prior to use. Do not use if outdated.
H/Warnings/OSRAM/MHID.doc
Printed on: 9/29/2006 9:21:00 AM
Page 3 of 6
should be free from dirt and corrosion. Socket/connector condition may affect lamp life.
Replace socket/connector or lamp if deterioration (pitting, scorching, corrosion, etc.) is
observed.
Please note that certain Display/Optic, AC metal halide lamps have dedicated pins or
connectors for high voltage ignition.
OPERATION:
1.
Magnetic current-limiting ballasts (chokes) provide sine-wave current operation for lamps.
However, electronic control gear (ECG) allows for square wave current operation, often at
higher frequencies. Some Display/Optic metal halide lamps have been designed for, and
therefore require, ECG square-wave operation. Please see OSRAM literature for power
requirements for your specific lamp type.
2.
Operate with compatible power supply and fixture only.
3.
OSRAM Display/Optic metal halide discharge lamps are designed for either hot re-start (high
ignition voltages) or cold start (low ignition voltages only). Please see OSRAM literature for
power requirements for your specific lamp type.
4.
To ensure that lamps operate at the correct power during AC operation, connections on the
ballast/choke in the power supply should be made to the correct voltage taps; i.e., tap voltage
should match input line voltage. To avoid wall blackening, overheating or other premature
failure modes, OSRAM strongly advises against operating Display/Optic metal halide lamps at
higher than rated wattage (“boosted operation”). Only OSRAM HMP Display/Optic metal
halide lamps are offered with a unique power feature allowing for operation at increased
wattage of up to 1.5 times their rated wattage, but with reduced service life. For safe lamp
operation and optimum performance, use only those ballasts/power supplies that have been
approved by OSRAM. See your OSRAM dealer for a list of approved equipment.
5.
Dimming of Display/Optic metal halide lamps, like incandescent lamps, causes a drop in
luminous output. If a metal halide lamp is dimmed by electrical means, it will not reach its
optimum operating state and, unlike incandescent lamps, will not last longer. When dimmed,
the lamp wall temperature falls more rapidly on a lamp that has no outer jacket. In metal
halide lamps without an outer jacket, reduced power operation causes an increase in the color
temperature and a reduction in CRI. Lamps with outer jackets can have either a vacuum or
filling gas (often Nitrogen) within. Metal halide lamps with outer jackets tend to maintain
their color properties better under dimmed conditions because the outer jacket provides
thermal insulation against internal lamp cooling.
6.
Display/Optic metal halide lamps need 5 to 20 minutes (depending on lamp type and cooling
conditions) before they reach their operating temperatures. To ensure proper ignition on
subsequent start-up, lamps should not be switched off during the warm-up period.
7.
Average service life of these lamps is determined by the ON/OFF duty cycle. Lamp
performance is reduced with increased duty cycle.
OPERATING POSITION:
