Features of operation of mercury-quartz lamps


Nuances in use of mercury-quartz lamps

Service of lighting installations with mercury-quartz lamps has some features therefore, depending on type of lamps, it is necessary to uchiyotyvat the following requirements.

Устройство ртутной лампы

Device of the mercury lamp.

Lamps like DRL join in network with по­мощью PRA. As the industry lets out two - and four-electrode lamps, the PRA type has to correspond to lamp type. The 80, 125, 400 and 700 W lamps are issued only the four-electrode design, and the 250 and 1 000 W lamps are made in two modifications. Therefore this zameyochaniye in particular belongs to two last types of lamps.

As the exception of the lamp of the four-electrode konyostruktion can join with PRA for two-electrode lamps of the corresponding power, but at the same time from PRA the discharger has to be taken out. If the discharger is not withdrawn, then PRA will give the vysokovoltyony setting fire impulse on the lamp, and the lamp will fail.

Схема включения ртутно-кварцевой лампы ДРТ

Scheme of inclusion of the mercury-quartz lamp of DRT.

External ambient temperature exerts strong impact on tension of ignition of lamps. If the lamp is operated in the enclosed space where temperature does not fall below zero, then for the zazhigayoniya of the lamp not less than 200 V.V these conditions for four-electrode lamps are enough give on it tension normal PRA in the form of the throttle can be used. But this PRA will not provide ignition of such lamp in installations of outside lighting where the tempeyoratura of air can change up to 30 °C and below, and on the lamp it is required to give tension not less than 300 Century.

In this case it is necessary to apply other PRA type, for example the stray transformer. It is necessary to pay attention as the difficulty observed in winter time with ignition of lamps can be explained insufficient napryazheyoniy the no-load operation created by PRA to this circumstance.

Lamps of DRL are expected operation in vertiyokalny situation, the socle up. However at the neobkhoyodimost it is possible to operate it in any situation. Work of the lamp in inclined situation can exert some impact on the term of its service. At the ekspluatayotion of lighting installations with lamps of DRL it is required to watch the condition of the installation power compensating low коэф­фициент.

Now при­нято to install the compensating condensers at group boards or on substation. Such system of compensation is called group. Also compensation of low power factor by installation of the condenser at each lamp is possible. In this case this system is called individual. If the network circuit is calculated taking into account kompensiruyuyoshchy installation, then its shutdown can lead to the current vozyorastaniye almost twice that conducts to the overload of network and transformers. The lack of the compensating ustayonovka demands increase in section of wires of network and the moshchyonost of transformers.

At operation of two-electrode lamps of DRL very widespread lack of PRA is the otsutyostviye of the setting fire impulse therefore lamps are not lit. It is necessary to check reliability of the konyotaktirovaniye of current carrying elements of the discharger and the payonela on which it is established and to try to replace the old discharger with new. If at such replacement the lamp begins to be lit, so the razyoryadnik failed. It must be kept in mind that service life of the discharger is much less than lamp service life therefore they need to be replaced periodically.

If PRA is not built in the lamp, and installed separately from it, then at all repairs and surveys reliability of the electrical link in all connections and the condition of grounding of the PRA body and lamp is surely checked.

Принципиальная схема ртутной лампы

Key diagram of the mercury lamp.

Lamps like PRK the normal working provision of the lamp in the device have horizontal. The otkloyoneniye from this situation no more than on 15 ° as during the work of the lamp in other situation overheating of cathodes and reduction of duration of burning of lamps is possible is allowed.

It is necessary to operate lamps with PRA, postavlyaeyomy completely with the device expected vklyucheyony lamps of this type. At shutdown of the lamp its povyotorny ignition cannot be made to the full okhlazhyodeniye. For this purpose the period is required no more than 10 min.

At installation of the new PRA or replacement which failed it is necessary to be convinced available in it is mute the noise suppressing condenser installed paralyolelno to the lamp, otherwise the device moyozht to be the source of radio interferences. If such konyodensator is absent, then parallel to the lamp it is necessary to turn on the condenser with a capacity of 0,05 microfarad for lamps of the PRK-4 type also 0,005 — 0,007 microfarad for all other types of lamps.

When replacing of the burned-down lamp on new before its installation in the device it is recommended to wipe it with cotton wool, the wetted in alcohol. In the course of work of the lamp the large amount of heat overheating it vydelyayotsya. Therefore if the lamp is established in closed аппа­рат, not having ventilation, it is necessary to provide forced ventilation of the device surely.

PRK lamps when burning intensively radiate in ultra-violet area of the range and can have harmful effect on eyes of people. In this regard for protection of eyes when using of such lamps it is necessary to put on goggles. Under the influence of ultra-violet radiation at the careless ispolyyozovaniye of the lamp on skin there can be burns therefore application of these lamps has to be controlled by mediyotsinsky personnel, and at its absence necessary precautionary measures have to priyonimatsya.

Lamps like DRSh normal working situation have vertical. The nebolyyoshy deviation from the vertical, but no more than 10 ° is allowed. For the lamps working at the direct current, the anode, the socle having big diameter with the sign "+" it has to be located below and connected to the positive pole of the power source. In alternating-current lamps the electrode of ignition has to be located from above. The lamp in the device fastens for legs or for socles of current carrying electrodes.

Схема подключение мощной УФ лампы

Scheme connection of powerful UF of the lamp: L — DRT lamp; DB — the throttle; To — the button; C1 — the condenser ёмк.

For ensuring normal ignition of lamps it is necessary to watch size feeding the napryazheyoniya of network which has to be for lamps of 127 V not lower than 115 V and for lamps of 220 V not lower than 200 — 205 Century. Temperature of okruyozhayushchy air which has to be not below 15 °C exerts impact on process of ignition of the lamp.

During the work of lamps their forced cooling, but when lamps are installed in the closed equipment, the sizes of the equipment and its ventilation have to be calculated so that the tempeyoratura of air of the pas distance of 5 — 6 cm from the flask of the lamp did not exceed 250 °C is not allowed. After shutdown of the lamp its povyotorny ignition cannot be made before full cooling on what 5 — 6 min. are required.

In use equipments with lamps like DRSh it is necessary to watch closely the nadezhyonost of contacts of all electrical connections, and the takyozha reliability of grounding of the body of the equipment. As the lamp can be the source of radio interferences, it is necessary to check availability of the condenser which is switched on paralyolelno to the lamp and the condensers blocking pitayuyoshchy network and installed directly at the armayotura with lamps.

The quartz glass of which lamps are made quickly loses the transparency, crystallizes at pollution of its surface. Therefore does not rekomenyodutsya to take the lamp barehanded, it is necessary to put on hlopyochatobumazhny gloves. Before inclusion of the lamp from its surface delete dust, fat traces from the prikosnoveyoniya to its surface with fingers, having wiped it with cotton wool, the wetted in alcohol.

During the work of the lamp in it very big vapor pressure of mercury therefore lamps are explosive develops. The personnel and the equipment which are near the lamp have to be protected from flask splinters in case of its explosion. It is also necessary to consider that lamps radiate the significant amount of invisible ultraviolet rays, and in this regard it is necessary to take measures for protection of operational personnel against action of ultra-violet radiation. For protection of eyes ispolyyozut special goggles.

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