Precautions for the use of metal halide lamps

- May 28, 2019-

Precautions for the use of metal halide lamps
Metal halide lamps rely primarily on metal halides as luminescent materials, and metal halides are present in solids in the lamp. Therefore, the lamp must be filled with a small amount of flammable gas hydrogen or helium to ignite the bulb. After the lamp is ignited, it first works in a low-pressure arc discharge state. At this time, the lamp has a very low voltage of about 20 to 20 V, and the light output is also small. At this time, heat is mainly generated, so that the entire lamp body is heated, and the metal halide introduced into the lamp is introduced. The substance evaporates continuously with the increase of temperature, and becomes a metal halide vapor. Under the action of heat convection, it continuously flows to the center of the arc, and a part of the metal halide is decomposed by the high temperature of 5500-6000K to become a metal atom and a halogen atom. Under the metal atom is excited to emit light; another part of the metal halide is not decomposed by the high temperature of the arc, and under the dual action of high temperature and electric field, direct excitation forms molecular luminescence.
(1) Check if the lamp has input power, and use a multimeter to measure whether the voltage at the power input terminal is normal.
(2) Check the lamp for deformation, perforation and other abnormal phenomena.
(3) Remove the bulb and check if the contact piece in the lamp holder is broken or ablated, and the bulb is in good contact with the lamp holder.
(4) Carefully observe whether there are any signs of ablation on the terminal block and ballast coil in the lamp or ballast. Whether the capacitor or the trigger has an abnormality.
The voltage of the metal halide lamp: the voltage when the phone hangs up is about 50 volts, about 10 volts when off-hook, its ringing voltage is about 80 volts when there is a call, the current of the telephone line is very small. The current in the off-hook state is about 20 to 30 mA. Does not directly harm the human body.
Metal halide lamp illumination is widely used in plazas, tall buildings and places where high illumination is required. Its inner tube is filled with an inert gas and mercury swallow and a halide. The halide is composed of a metal compound such as iodine, bromine, tin and sodium. The lamp is characterized by high luminous efficiency, high power, and low life. It takes about 15 minutes from start to steady normal illumination.
1, 220V AC power line (red line L, blue line N, yellow line / green line yellow green line ground line E)
2, the inductance ballast (by the edge termination 220V power line L and any line of capacitance, the inner terminal is connected to the trigger B)
3. Power compensation capacitor (any one of the two wires is connected in parallel with the 220V live wire and the other is connected to the neutral wire N)
4, CD-7 electronic trigger (three lines respectively B-connect ballast, LP-connected bulb any line, N connected to the zero line)
5, the lamp head (two lines one connected to the trigger LP, one connected to the zero line N)