Dnat arc sodium tubular lamp. HPS lamp: specifications and connection. How it works

In our time, there are quite a few different high-pressure arc lamps. But the HPS, i.e., an arc sodium tubular lamp, is distinguished by the highest efficiency among them. Its device is almost similar to DRL - arc mercury, only the glow is much brighter, it is more economical and durable. HPS power can be from 30 W to 1 kW, depending on the area in which it will be used.

As for its service life, it is about 25 thousand hours - few of the lighting devices can boast of such. But more on the benefits later. Now it makes sense to consider the power supply circuit of such a gas-discharge lamp. After all, although such a light source is somewhat similar in design to DRL, it still has its own characteristics in connecting it.

Principle and connection diagram

In addition to the inductive choke, which limits the strength of the arc current, the PRA or electronic ballast (electronic ballast) circuit includes an IZU - a pulsed igniter. It is it that is responsible for creating impulses with a voltage of several thousand volts.

If you pay attention to the sodium lamp connection diagrams, you will notice that there are two options for how to connect the HPS lamp. In the second case, lighting devices are connected through a 3-pin pulsed igniter, although this does not play a big role. But the first diagram shows the inclusion of HPS with a capacitor. This is done in order to smooth out the voltage supplied to HPS, and thereby increase its service life. The connection of HPS lamps to the inductor must be carried out in series, and IZU with a lighting device must be connected in parallel. In this case, it is the phase, and not zero, that goes to the light bulb through an inductive choke.

In addition, the rated power of the ballast (or electronic ballast) connected to the lighting device must match the same parameter of the sodium lamp.

The following point is very important when installing the circuit. Do not ignore flagged contacts. If zero should be connected to it, you do not need to throw a phase there, and vice versa. Of course, the lamp will light up, but the service life of both the lamp and the ballast will be significantly reduced from this.

Pros and cons of HPS lamps

Such sodium lamps have several main advantages:

Very high efficiency.
The luminous flux from such a lighting device is quite stable.
The strength of this stream is high and is about 150 lumens/watt.
Durability is one and a half times longer than other similar lamps.
optimal, a glow of a pleasant golden hue.
Works great even in fog or snow.

Almost ideal as a phytolamp, because the radiation from HPS actively helps plant growth.
These lighting devices show themselves well in operation at a temperature difference from -60 to +40 degrees Celsius.

But, of course, not a single device is without flaws - there are no ideal products. 5 main cons:

These lamps are extremely explosive.
There are heavy metals inside.
It takes a long time to ignite (sometimes up to 10 minutes).
When used as a phytolamp, it is not suitable for growing radishes, onions and lettuce as they are non-flowering.
If it is necessary to connect higher power HPS (for example, HPS 250 or HPS 400), additional cooling of the lighting device is required.

Principle of operation

The structure, as already mentioned, is very similar to the DRL by the presence of a glass bulb, inside of which there is a tube or burner. Only here it will not be possible to use glass for the manufacture of a tube in DNAT (as in DRL) due to the very high temperature of sodium combustion. For this, a special material is used - polycrystalline alumina. Only such a material will allow 90% of the glow to pass through and at the same time be resistant to sodium vapor.

Molybdenum is used to make electrodes. The luminous efficiency of such lamps is increased with the help of xenon or mercury, but argon is present in the sodium lamp to facilitate starting.

A vacuum is created inside the flask to maintain its integrity, because during operation, the sodium arc tube lamp heats up to 1,400 degrees Celsius. Naturally, when the lamp is working, it is difficult to prevent air from entering through the holes, but special gaskets are provided for this case.

After applying a high-voltage pulsed current through the IZU, an electric arc is formed in the HPS, which heats up the tube. This happens within 6–9 minutes, after which the sodium lamp flares up at full strength. So the principles of operation of HPS and DRL are almost exactly the same.

Some faults

Like any gas discharge lamps, sodium lamps may start to flash over time. For example, a light device, having warmed up, suddenly goes out, periodically repeating this action. It is necessary to replace the lamp, and if this does not help, it makes sense to measure the voltage in the network. It is possible that it is too low, and it is not enough to support the normal burning of sodium.

It happens that this happens infrequently - then a bad contact or a power surge is possible. Well, another possible reason is an interturn short circuit. This is treated only by replacing the throttle. Provided that the lamp is new and the ballast is in order, you just need to wait until the HPS is developed. This usually takes 2-3 hours.

If a crackling of a pulsed igniter is heard, and the lighting device does not ignite at all, the reason is most likely a broken wire from the lamp to the IZU, or HPS and electronic ballast.

It makes sense to inspect the connections of the ballast for sodium lamps - this happens when they burn out, and therefore you should clean the contacts, check the wiring and try to light it again.

Summarize

The arc sodium tube lamp is unique in its kind. Of course, she has flaws, and the main one is color distortion. And even this is fixable, just raise the lamp higher. But still, the minimum power consumption, the brightness and warmth of the glow, coupled with its durability, make it a leader among similar lighting devices.

Of course, someone may complain about the complicated connection and high cost, but it all pays off. Yes, and there are no special difficulties in installing the HPS lamp connection circuit, even a person with the slightest skills in electrical installation can connect a sodium lamp.

Well, for street lighting, such a lighting fixture is clearly out of competition, unless, of course, LED lights are taken into account.

HPS lamps are sodium lamps in the form of tubes, inside of which there is a gas discharge. The source of light in gas discharge lamps is the evaporation of sodium. These lamps emit a bright orange color, which is regarded as a minus, because the color quality is unacceptable. Sodium lamps (NL) are used to illuminate roads, bridges or areas in production, but only if there are no strict requirements for lighting standards and its index. Lamps of this type illuminate mainly tunnels, pedestrian crossings, i.e. those places where contrast visibility is always needed.

What does a HPS lamp look like?

Application

These lamps are significantly superior to conventional lamps and typical gas discharge lamps. HPS sodium lamps in the modern world are the most economical and efficient lamps. There is a wide choice of power (from 70 to 400 W), and this allows the consumer to choose the required lamp for specific purposes.

Bright orange HPS lamp light

HPS lamps are divided into low pressure sodium lamps (NLND) and high pressure lamps (HPLD). Their difference suggests the use of these lamps in various highly specialized areas.

NLND

The first NLND began to be used about 80 years ago. In the Soviet Union, these lamps were not immediately included in the series, because. were mercury gas-discharge, and there was no need for NLND.

The disadvantages of these lamps include the fact that sodium vapor cannot contact plain glass for a long time, therefore special borosilicate glass is used in lamp bulbs.

The outer glass flask creates a vacuum that plays the role of a thermos. This is necessary for the independence of sodium lamps from external temperature. In the modern world, these lamps are significantly inferior in popularity to NLVD lamps due to the fact that they have greater functionality and a variety of characteristics.

NLVD

The electric arc in high-pressure lamps is too hot, so aluminum tubes are used for these lamps, or rather, its oxide. These tubes guarantee protection not only from sodium evaporation, but also from elevated temperatures.

HPS lamps of various power

Such a transparent and chemically resistant tube is inserted into the outer flask, which is made of special glass. A vacuum is artificially created in the cavity of the outer flask, and the effect of a thermos appears.

The high-pressure lamp igniter is filled with a gas mixture (buffer) of different composition, to which sodium amalgam is added. There is also a special type of NLVD, sharpened to environmental standards, they do not contain mercury.

When such a high-pressure lamp reaches the end of its life, the visible spectrum of the lamp spontaneously changes from light red to dark red.

If the lamp began to shine with a non-standard light (usually red light), then it is time to change it.

Compared to NLND lamps, color rendering is improved. This is due to the fact that the light output of a high pressure lamp is 150 lm / W, and a low pressure lamp is 200 lm / W.

HPL lamps are often used in industrial workshops or greenhouses for lighting and progressive plant growth. Such lighting allows plants to increase the offspring and grow almost all year round.

Such lamps are widely known not only due to crop production and industry. Due to the wide range of characteristics, it is quite possible to choose the necessary lamp for personal needs. For example, table lamps are made from some lamps. Their advantages are durability and good lighting.

Device

Externally, the lamp looks like the most ordinary electric lamp. The difference from other lamps is that there is an igniter in the glass bottle of the sodium lamp, which looks like a tube made in the form of a cylinder of aluminum oxide - the material is completely clean. Inside the tube is filled with sodium vapor mixed with mercury. There is also an incendiary gas - xenon. An arc (electric discharge) appears in high-pressure sodium vapors.

These lamps contain a certain amount of mercury, so these lamps should not be disposed of in a garbage container, but in a specially designated place.

Principle of operation

The type of operation and the requirement for current sources for NLVD and typical DRLs, even of the same power, are different. Therefore, power supply and operation from the same current sources with the same control gear (ballasts) is not allowed.

The NLVD igniter does not allow the installation of ignition electrodes from DRL lamps. Therefore, to ignite a sodium lamp, a breakdown of the interelectrode space is required. That is why the composition of the ballast included IZU (pulse ignition device), made in the form of one separate unit.

Pulse igniter

NLVD, which requires IZU, is marked in the form of the Latin letter "E" in a triangle.

If the replacement of high-pressure lamps with DRL and vice versa is necessary, then a replacement can be made, but with a lower power. If it is necessary to replace a 250 W DRL lamp, then a 210 W DNS is installed instead. The lower power of the DNaS 210 lamp has many times greater luminous efficiency.

To turn on such a lamp in the standard circuit for switching on DRL lamps, the burners are filled with a special argon (with neon elements) mixture. The difference will be noticeable only against the background of standard HPS lamps filled with xenon.

To improve the design, a metal wire is used, which is wound onto the igniter (burner) close to the walls. This device is called a "starter antenna" and increases the electrical capacitance, that is, reduces the voltage before breakdown.

Such lamps have a special marking on the flask in the form of the letter "l".

The lamp contains mercury, which means that if it breaks, it is urgent to evacuate people from the room where it happened. Next, collect the fragments of the lamp, wash the impact site, dispose of the rag that was used to wipe the impact site, and ventilate the room.

Price

HPS lamps are several times more expensive than their competitors. This is due to the fact that sodium lamps have a narrow specialization in terms of power selection, color output and temperature. For example, an NLVD lamp with a nominal power of 400 W is not replaceable for lighting greenhouses, although it immediately imposes restrictions on the distance from the plant (a 400 W lamp should be no closer than half a meter from a living plant). Unlike lamps and other gas-discharge lamps, the choice of power is the main criterion when buying an NLVD lamp.

The price of such a lamp (assembled in a separate case) starts from 2 thousand rubles. The price of other types of lamps is at least two and a half times lower. Despite the high price of such a lamp, its main advantage - a long service life, up to 25 thousand hours, covers the rest of the disadvantages.

Lamp in spotlight housing

Where can I buy

Finding a sodium lamp for sale is quite simple. Almost any large store that sells lighting equipment has several types of different NLVD and NLND lamps in stock. If the buyer has not found a suitable lamp, you can always place a purchase order. You should not buy lamps in stores that do not give a long-term warranty, because such lamps are designed for a long service life, and in the event of a factory defect, money for the goods cannot be returned.

One of the best manufacturers that have proven themselves well are the Russian company Reflux and SYLWANIA.

SYLWANIA HPS lamp

How to connect

Connecting such lamps requires special knowledge (especially when connecting industrial lamps), so it is better and more reliable to contact a specialist or a specialized company.

An important feature of connecting a HPS lamp is that its functionality directly depends on the connection and installation technique. It is believed that the lamp should be installed in a horizontal position, since the light flux is emitted in different directions. Horizontal installation guarantees correct lighting, because a reflector is installed on the covered side of the luminaire.

To install a lamp in a lighting system, an electromagnetic ballast is needed to warm up the system and put it into operation normally. When the system is put into operation, the phase goes to the electromagnetic ballast, then to the IZU, which, in addition to the phase, has a zero. Only after that the lamp itself is connected. This whole system is built into the lighting system so that there is no stroboscopic effect, that is, so that the lamp does not blink. This not only protects the lighting system itself, but also saves the life of the lamp.

Comparison of HPS lamps with LED

LED lamps have been used for a long time and have proven themselves well in the market. Therefore, when choosing a lamp, the buyer compares it with competitors.

In the field of LED lamps, a breakthrough has recently been made due to some new properties and characteristics of LEDs. Therefore, it is necessary to figure out what is better and what is worse than the main competitor of sodium lamps.

Modern technologies using the latest materials have made it possible to increase the brightness of simple LEDs by more than 22 times. Therefore, when comparing HPS lamps and LEDs at the very beginning, the advantage goes in the direction of LEDs. They have a high coefficient of performance (COP), therefore, when calculating the cost of electricity, the LED gains pluses. Also, the advantages of LEDs include resistance to temperature and voltage changes in different directions.

However, when comparing such powerful LEDs and conventional HPS lamps, LEDs lose out as soon as the height of the luminaire suspension increases. This is due to the fact that the LED basically does not illuminate, but glows. This is corrected in special lamps and in car headlights by directing LEDs, but the cost of such a lamp immediately goes far beyond reasonable limits.

Another important disadvantage of LEDs compared to gas discharge lamps is cold light. That is why LED lamps do not make sense to illuminate greenhouses. It is because of these disadvantages that LEDs cannot compete with HPS lamps.

Connection. Video

The video below shows how to connect the DNAT lamp to a mains current.

Summing up, we can say that in the modern world there are no competitors to such highly specialized lamps. It has such advantages that it is impossible to beat many competitors.

Sodium lamps are lighting devices that use metal vapor as a working medium. Unlike the other two classes of discharge devices. For example, mercury lamps use a discharge in gases, they distinguish a family of lighting fixtures, where metal compounds become the working substance.

Key Features of Sodium Discharge Lamps

It is believed that sodium light bulbs have the highest light output, which implies an impressive efficiency. The products are characterized, among other things, by a long service life. During operation, the light output decreases slightly. Operating parameters (of high-pressure lamps) do not depend much on the ambient temperature (overheating is excluded by a properly implemented design). Sodium light bulbs are in demand for street lighting. There are serious disadvantages:

Not too reliable color reproduction (coefficient values - 25). This has long been considered a major limitation for the use of discharge lamps in the home. Human skin looks extremely bad in such lighting.
The discharge in sodium vapor is characterized by a deep pulsation, which leads to rapid visual fatigue. The flickering effect is harmful to the nervous system and a number of aspects of human health. The mentioned phenomenon is explained by the complete inertia of the arc in sodium vapor - the glow repeats the law of the applied voltage (the network usually has a sinusoid with a frequency of 50 Hz).
As the resource of life is spent, the power consumption of the sodium lamp gradually increases and increases by 40% relative to the initial one.
The ballast of sodium lamps is bulky (takes up a lot of space) and is characterized by high losses (up to 60% of the total energy consumed).
The presence of a starting choke predetermines a low power transfer coefficient (up to 0.35). Which requires a solid block of compensating capacitors to eliminate the reactive part.

The above explains the use of sodium lamps mainly for night lighting, especially for non-residential facilities: workshops, warehouses, railway stations. Additionally - for storage facilities, highways, architectural structures. The yellow light of a low pressure sodium lamp allows a person to distinguish details at a relatively low radiation intensity, and excellently passes through fog in bad weather conditions. This specificity makes it possible to create a multitude of signaling installations based on the described devices.

Some of the above shortcomings can be eliminated by using inverter-type electronic ballasts. This reduces power consumption, due to the lack of a starting choke, the power factor reaches 0.95. Of course, the mass of electronic ballast is small. This is known to a person who knows about the advantages of LED and discharge lamps with Edison thread E27. All electronics fit in the base here.

The service life of high pressure sodium bulbs ranges from 12 to 28 thousand hours. These are competitive values, in terms of workdays it is 4 - 9.5 years. Gradually, the voltage drop across the lamps increases at a rate of 1 - 5 V annually. What becomes the reason that provokes rejection.

The bulb of low pressure lamps is usually cylindrical. For high pressure products - sometimes mushroom-shaped with an internal reflector or ellipsoidal. In the latter case, the emission spectra are graded in terms of power: for its average values, the pressure in the flask is maximum, explaining the mentioned division. The spectral characteristics are affected by mains voltage (unless an electronic ballast is used). The service life is also critical to the amplitude: an increase or decrease in voltage by only 5% leads to a sharp aging of the product.

For ordinary consumers are of interest. The corresponding coefficient of products reaches 83, which is recognized as an excellent indicator. For example, for LED bulbs, 70 or more are considered typical values. The latter are massively used in everyday life, there are few who want to complain about such parameters. And given the cost-effectiveness of sodium bulbs, we believe that the devices will become a worthy competitor for other families of lighting devices.

The principle of operation of sodium lamps

In a sealed flask, conditions are created for the evaporation of sodium. D-lines at 589 and 589.6 nm are used to produce light. Sodium lamps come in high and low pressure. According to the generally accepted classification, these are, respectively, from 30,000 to 1 million Pa and from 0.1 to 10,000 Pa. This state of affairs arose on the basis of long studies of the specifics of the discharge.

It has been established that the maximum light output is observed at pressures of 0.2 and 10,000 Pa. The first sodium lamps, created in 1931 by Marcello Pirani, operate at the first extremum of the function within the specified interval at a current density of 0.1 - 0.5 A per square centimeter. The most favorable conditions for light emission are achieved at temperatures of the liquid phase in the range of 270 - 300 degrees Celsius (the base temperature is at least twice lower). Lamps operating at a pressure of 0.2 Pa are more efficient.

Low pressure sodium lamps

Low pressure lamps are extremely efficient. The wavelengths indicated above become dominant, but far from being the only ones in the luminescence spectrum. In low pressure lamps, most of the lines lie in the area of \u200b\u200bsensitivity of the eye. This means that the light is as bright as possible. In other words, low-pressure lamps have an attractive efficiency.

In laboratory models, the efficiency reaches 50-60%. As a result, the luminous efficacy rises to 400 lm/W (the theoretical limit for the current level of technology is 500 lm/W).

For comparison. The 9 W EKF LED bulb (similar to a 75 W filament) produces a flux of 830 lm. The figure is considered a good indicator of energy saving. Although the light output, it is not difficult to guess, is "only" 92 lm / W. It becomes clear how effective low-pressure sodium lamps, invented long ago, in 1931.

In practice, you have to make sacrifices (Philips bulbs are still good and reach a light output of 133-178 lm / W). The temperature of the bulb rises to the required 270-300 degrees Celsius due to special measures for thermal insulation (exceeding the radius of the bulb over the maximum effective one) and some increase in the operating current to the optimum. As a result, the efficiency of real products released for mass sale does not reach the above limits. But it remains elevated so that sodium light bulbs are called energy-saving.

Thermal insulation is sometimes supplemented with other measures. A reflective jacket made of semiconductor materials transmits useful yellow radiation outward, but reflects infrared radiation inward. The temperature inside rises further. But the design of a sodium lamp is more complicated.

The ignition of the arc is facilitated by the addition of some neon and argon. This greatly reduces the voltage developed by the driver. Due to the presence of impurities, the bulb glass does not absorb argon. The radius of the lamp is taken a little more than the optimal one and is 15-25 mm. The oxide cathode is usually bifilar or sintered (powder sintered). The material used is tungsten activated by alkali (alkaline earth) metals.

High pressure sodium lamps

In addition to sodium, mercury vapor and xenon, which reduces the ignition voltage (up to 2-4 kV), are added to the gas mixture. The pressure in the flask is in the range from 4 to 14 kPa. It is easy to see that, according to the general classification of discharge lamps, the indicated range refers to low pressure. For sodium lamps above 14 kPa, the indicated parameter does not rise. The range of 4 - 14 kPa is taken out in the discharge of strong pressure.

The maximum efficiency lies in the region of 10 kPa. The partial pressure of sodium vapor is a tenth or twentieth of the total. The rest is mercury and xenon. The pressure of the latter (cold) is 2.6 kPa. If a mixture of neon and argon is used to reduce the ignition voltage, the light output of a sodium lamp is reduced by a quarter.

In the spectrum of high-pressure sodium lamps, in addition to D lines, activity is noted in the blue-green part of the spectrum. Due to which the given shade is not yellow, but golden-white (the color temperature in the warm interval is 2000 K). The color rendering index (maximum at 2500 K) can be increased by increasing the partial pressure of sodium vapor and the diameter of the flask. At the same time, the luminous efficiency is almost halved, and the service life is reduced. The color temperature rises. In view of the negative results described above, such measures are rarely taken.

Aluminum ceramic is used as the bulb material. Ordinary silicate glass is unsuitable, sodium vapor under the influence of a considerable temperature then enter into a chemical reaction. The compounds formed are stable, and the flask noticeably blackens within a few minutes after the start of the product. The changes are irreversible, under the influence of strong pressure there is a possibility of complete destruction of the glass.

Polycrystalline ceramics and a tubular single crystal with wall thicknesses from 0.5 to 1 mm are equally resistant to the action of an aggressive environment up to a temperature of 1600 K, with some margin relative to the optimal point. Ceramics exhibits a decent visible light transmittance, accounting for 30% of the energy consumed by a sodium lamp.

Extreme temperatures require a special design of the bushings. Made of niobium with a small (1%) admixture of zirconium, they are sealed at the entrance to the flask with special glass cement (capable of withstanding the specified aggressive conditions). So sophisticated in composition, the alloy was chosen for a reason. Designers have found a material whose coefficient of thermal expansion is close to that of ceramics. As a result, it is possible to avoid deformations at the joints and seams. The same idea is used in metal window frames. It is known that the coefficient of thermal expansion of aluminum is close to the values of glass.

High pressure sodium lamps are characterized by inertia. When first ignited, the light is yellow and monochromatic. Gradually, the product enters the mode with a simultaneous expansion of the emitted spectrum. To re-ignite the arc, the gas cools down, taking 2-3 minutes. In order not to exceed the operating temperatures, it is required to exclude the reflection of radiation onto the bulb. Otherwise, the sodium lamp fails from overheating.

A decade ago, sodium lamps were used to illuminate roads and streets almost everywhere. With the advent of LED light sources, they began to be used somewhat less frequently, but nevertheless, HPS lamps are in no hurry to give up their positions. What are these lamps and why have they been holding the lead among street lighting for more than a decade? Today we will try to find out.

Even today, the good old DNAT serve us faithfully

What is HPS and types of such lamps

DNaT lamps are one of the varieties of high-pressure sodium lamps - HPS Lamp - High-Pressure Sodium Lamp. DNAT is an abbreviation, the decoding of which means "Arc Sodium Tubular". There are several more varieties of devices of this type: DnaMT, DnaZ and DnaS. Let's see how they are arranged and how they differ from each other.

Sodium lamp design

Structurally, the device is a flask made of a special glass made of aluminum oxide Al 2 O 3 . During operation, the flask is heated to 1200 degrees Celsius. Such glass not only withstands high temperatures, but is also able to withstand the damaging effect of sodium vapor.

Two electrodes are soldered into the edges of the flask, which is called a burner. It itself is filled with a mixture of buffer (inert) gases with the addition of sodium amalgam: an alloy of sodium and mercury. Additionally, xenon is mixed into the buffer gases, it provides an easier start of the light bulb. The burner, in turn, is placed in another outer flask made of ordinary heat-resistant glass. Usually it is refractory borosilicate glass. A deep vacuum is created in the flask, and it itself is supplied with a base of one type or another for connecting to the mains.

Due to the vacuum, the outer flask plays the role of a thermos, which ensures the normal start-up and operation of the sodium burner at low ambient temperatures. At the same time, it reduces heat loss, increasing the efficiency and resource of the device.

HPS lamp device

The most common base mounted on HPS light bulbs is the Edison threaded base. For small power devices, E27 is used, for powerful illuminators - E40. Nevertheless, there are light bulbs with other types of bases, as well as double-ended ones.

HPS with an E40 base (left) and a two-socle soffit version

Sometimes two burners are installed in one outer flask. This increases the power of the device without a significant increase in its dimensions, and also slightly increases the efficiency and service life of the device due to less heat loss.

HPS lamp with two burners

Expert opinion

Alexey Bartosh

Ask an expert

In fairness, it is worth mentioning the existence of low pressure sodium bulbs. The burners of such devices are similar in design to the well-known flasks of fluorescent light bulbs. Their electrodes are spirals, and the device is started by heating them.

Low pressure sodium lamp

As I noted above, in addition to DNAT, there are several more varieties of sodium lighting devices:

DnaZ - with a mirror reflector sprayed onto a part of the outer bulb, directing the light of the burner to a certain sector;

DNAZ has its own reflector

DNAS - light-scattering. In this device, the role of a light diffuser is played by a special pigment deposited on the inner surface of the outer bulb. The spectrum of DNaS lamps is similar to daylight;

Both externally and in terms of the emitted spectrum, the DNaS resembles a mercury illuminator DRL

DnaMT - with a frosted flask. In fact, this is an analogue of DNAS, which is currently out of production. Designed for direct replacement of DRL lamps without compromising the quality of lighting.

Lamp DnaMT

Operating principle

When a supply voltage is applied to the electrodes of the burner and at the same time a high-voltage pulse, a glow discharge occurs in the flask, which begins to heat up the sodium amalgam. As the amalgam heats up, it passes into a vapor state, the resistance of the gas gap in the flask decreases, and gradually the discharge turns into an arc - the lamp flares up.

Typical HPS warm-up time is 10-15 minutes. At the same time, the temperature of the burner itself reaches 1200, and the outer flask - 250-300 degrees Celsius. To prevent the discharge from turning into an uncontrolled arc, a ballast is switched on in series with the lamp. Under the influence of an electric arc, sodium vapor begins to emit visible light in the yellow-orange spectrum (sodium resonance spectrum). In this case, the light output of the device is 150–200 lm / W, depending on the power and type of device.

HPS light bulb spectrum

How to start the HPS lamp

How to properly connect a HPS sodium lamp to the network? As can be seen from the above, it is not enough to supply voltage to the device: a cold burner has a lot of resistance and simply will not start. To create a starting high-voltage pulse, a special unit is used - a pulse igniter (IZU).

After starting the bulb, the current through it must be limited. Ballast is engaged in this: electromagnetic or electronic. The first one (EMPRA - electromagnetic ballast) is a choke - a coil with an open magnetic circuit. The second (electronic ballast - electronic ballast) is an electronic circuit - a current limiter.

ECG (left) and electronic ballast for lighting devices DNaT

The inductor is connected in series with the light bulb, IZU - in parallel. There are 2 types of IZU - two-pin and three-pin. The first is easier to connect and costs less, the second makes the circuit work more correctly. When using a three-terminal IZU, at the moment of start-up, a high-voltage discharge is applied only to the lamp, and not to the lamp + ballast, as is the case with a two-terminal device. The connection diagram of the illuminator using both types of IZU is shown below.

Schemes for connecting a HPS lamp using a two- and three-pin IZU

Please note that the diagrams indicate zero and phase. The ballast is always included in the break of the phase wire. There are also appropriate designations on the IZU, do not forget to follow them.

Ignition devices even have a wiring diagram for them.

Now about the capacitor C, which is indicated in the diagram by a dash-dotted line. It is not mandatory, but it will not be superfluous to put it. This capacitor serves to compensate for reactive power and to slightly increase the efficiency of the circuit. The capacitor must be non-polar paper and rated for a voltage of at least 400 V. Its electrical capacitance depends on the power of the lighting device. For HPS 250 W, 35 microfarads is enough, for HPS 400 W, the capacitance must be increased to 45 microfarads.

Expert opinion

Alexey Bartosh

Specialist in the repair, maintenance of electrical equipment and industrial electronics.

Ask an expert

For high-quality and long-term operation of the lamp, the ballast power must correspond to the lamp power. The rule “the more, the more reliable” does not work here! IZU is selected so that the power of the illuminator fits into the range indicated on its (IZU) body.

And one more piece of advice. Install the HPS bulb only with cotton gloves or a clean cloth. The fact is that the flask of the device heats up to 300 degrees. The fingerprints you left on the flask will burn off, and a layer of soot that does not conduct heat well will form. As a result, local overheating will occur, and the glass will burst. If you or someone else has already "captured" the light bulb, then wipe it with a napkin soaked in alcohol.

The device can be thrown away due to a crack that appeared as a result of local overheating of dirty glass

Disposal conditions

The DNaT lamp burner contains xenon and an alloy of sodium and mercury, therefore it is impossible to throw away the device as household waste! Burnt-out light bulbs must be handed over to specialized acceptance points. In addition, the materials of the burner and flask, although they look like ordinary glass, have a completely different chemical composition. Once recycled with ordinary glass, quartz and aluminum oxide will simply ruin the entire melt.

There are many places to dispose of mercury-containing devices, but we usually do not pay attention to them.

According to the current legislation (Decree of the Government of the Russian Federation dated 06.05.2011 No. 354), the obligation to collect burnt out energy-saving lamps is also assigned to management companies, homeowners associations, housing cooperatives, etc. That is, to organizations that service the housing stock. Moreover, in case of failure to fulfill their duties, public utilities face a fine of one hundred thousand rubles or more.

Specifications and comparison with analogues

I have already said that HPS light bulbs are stubbornly holding their positions and are still widely used, despite the emergence of new types of light sources. Why did they gain such popularity? Let's compare their main characteristics with the LED and arc mercury lamps of the DRL, which you probably saw in street lamps.

The main characteristics of lighting devices DNAT, DRL and LED analogues

	Passport power, W	Created luminous flux, lm	Average service life, h
100	9 400	6 000
150	14 000	10 000
250	24 000	15 000
400	47 500	15 000
DRL-125	125	6 000	12 000
DRL-250	250	13 000	12 000
DRL-400	400	24 000	15 000
LED analog DRL-125	40	2 500	10 000
LED analog DRL-250	80	5 000	10 000

It is clearly seen from the plate that, consuming 150 watts, a sodium bulb provides that the DRL with a power of 250 watts. The only serious competitor of the sodium lamp in terms of efficiency is the LED lamp.

Expert opinion

Alexey Bartosh

Specialist in the repair, maintenance of electrical equipment and industrial electronics.

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5,000 lm LED lamp can compete with 13,000 lm DRL due to the creation of a directional light flux by LEDs, providing the necessary illumination in front of the device. This is exactly what is required from a street lamp. At the same time, the mercury lamp shines in all directions.

But, firstly, high-power LEDs cost ten times more than the mentioned lamp. And, secondly, the technology of super-bright diodes is not as mature as the technology for manufacturing HPS, which is almost a hundred years old.

If you add here a huge number of manufacturers of LED products, it turns out that the search for guaranteed high-quality semiconductor equipment becomes very problematic. As for the vaunted durability of LEDs, at such a high power, the crystals quickly degrade (lose brightness). At the same time, the resource of a diode lamp often becomes even less than the resource of a lamp with a HPS lamp.

Scope of application

The peculiar light spectrum of HPS bulbs, as it turned out, is ideal for lighting streets and highways. It is precisely because of their spectrum that street lighting with HPS was used all over the world until a dozen years ago.

Having an anti-fog effect, the yellow-orange light provides good visibility on the road and does not blind the driver. If we take into account that sodium lamps are the most economical among gas-discharge devices, and even more so incandescent bulbs, there is nothing strange in the fact that almost 100% of the roads were illuminated by HPS.

The use of HPS lamps for lighting streets and roads

In recent years, HPS lamps have been partially replaced by LED ones, but in street lighting this happens much more slowly and more reluctantly than in everyday life.

Plants also liked the emission spectrum of HPS lamps. This determined another area of application of sodium devices: to illuminate plants in greenhouses and places where sunlight is not enough. You must have seen greenhouses lit with a soft yellow-orange light - these are HPS lamps.

The use of HPS lamps in greenhouses to illuminate plants

Advantages and disadvantages

Like any other lighting fixtures, lamps with HPS lamps have their advantages and disadvantages. The benefits include:

High light output. According to this parameter, HPS lamps occupy a leading position among gas-discharge lighting devices, although they are inferior to LED lamps.
Long service life. MTBF for HPS lamps reaches 15,000 hours. A powerful LED lamp with the declared brightness will work as much or not much more.
Relatively low cost. The lamp production technology is not particularly complicated and has long been debugged (the HPS lamp is almost 100 years old!), and the device itself does not contain expensive materials. In this regard, LED lighting devices catastrophically lag behind sodium ones - they are ten times more expensive.
Anti-fog effect. The yellow-orange spectrum emitted by HPS lamps is poorly absorbed by water. Even with rain and heavy fog, the quality of lighting remains at a fairly high level.

You have probably seen headlights with yellow glass on cars - these are fog lights. They use the same principle, but the yellow-orange spectrum is created not by a lamp, but by a filter.

As for the shortcomings, they are very significant:

Short . The HPS lamp emits light in a narrow yellow-orange spectrum. The color of almost all objects in this light is greatly distorted. It is because of the low quality of light that sodium lamps are absolutely not suitable for use in residential and industrial premises.
High ripple. When using an electromagnetic ballast (choke), the light of the HPS lamp pulsates at twice the mains frequency. In this case, the ripple coefficient can reach 15-20%. With a long stay under such light, the eyes of a person quickly get tired. The problem is completely solved by using electronic ballasts, but their cost is often higher than the cost of the lamp itself.
High operating temperature. During operation, the temperature of the HPS lamp reaches 300 degrees, and the ballast elements (in particular, the choke) heat up to 100 degrees. This not only threatens with serious burns if accidentally touched, but also requires the adoption of special fire safety measures.
Difficult start at low temperatures. Due to the design features of HPS lamps, it is difficult to start at low ambient temperatures. This problem is partially solved by using an outer bulb with a vacuum, but nevertheless, in severe frost, the lamp may not start. For this reason, the use of HPS lamps in the Far North is not recommended.
Long ignition time. After switching on, the lamp barely shines and only gradually flares up as the burner warms up. HPS lamps need 10-15 minutes to enter the operating mode. The hot lamp that has just been turned off will not immediately start: first, the bulb needs to cool down, and then start up again and flare up.

At the moment, sodium lamps have been widely used for lighting in greenhouse conditions.

These elements are the most economical in terms of energy consumption. Since the lighting of greenhouses and greenhouses is required quite large and for a long time, especially if you grow crops in the winter, these sodium-based lamps save money on heat. In addition to being used for greenhouses, they are also used to illuminate streets, tunnels, parks, airports, train stations, etc. Sodium lamps for plants are a very necessary element, without which a gardener can not do in the arrangement of greenhouses.

Although it is impossible to replace natural sunlight, sodium lamps are the most suitable alternatives.

The principle of operation and design of a sodium lamp for plants

Sodium lamps are abbreviated as DnaT. It is deciphered as an arc sodium tubular lamp. Its construction is very simple:

The glass bottle contains a special burner.
The burner is a cylindrical discharge tube.
The tube is made of pure alumina.
The tube contains vapors of mercury and sodium, the ignition gas is xenon.
The arc is created using sodium vapor and high pressure.
The lamp emits a golden white or orange color.

Plant lamp working principle:

To start the device, an electronic or electromagnetic ballast is needed.
You also need a pulse-igniting device (IZU).
The igniter is sold with a lamp included.
Modern lamps for greenhouses can be without IZU, for this they have antennas made of wire that is wrapped around the burner.

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Characteristics of the high pressure sodium lamp (HPVD)

Light output is equal to an average of 130 lm / W.
Service life 12,000-25,000 hours.
These are pretty good indicators, but there is also a downside to the coin - this is the impossibility of using it according to some of its characteristics in case bright light is needed. A sodium lamp does not give such a result. Color rendition in sodium products is low, the light is dim.
The lamp turn-on time for greenhouses is at least 10 minutes, which is also not very good for plants, since they can freeze in 10 minutes at low temperatures.
In cold winters, the air temperature in the greenhouse is lower and the lamps shine worse, since their work is directly proportional to the air temperature.
High pressure lamps have a high efficiency - about 30%.
The higher the power of a sodium lamp, the higher the luminous flux, luminous efficiency and, accordingly, the average burning time.
Color rendering can be improved with gas mixtures and luminescent materials.

The power of the lamp must correspond to the scope of its application. For example, for lighting greenhouses, plants should have lamps with a power of 70 to 400 watts. If you install more powerful lamps. than 400W, they can burn the vegetables in the greenhouse. Therefore, before installation, you need to consult with specialists in the store where you can buy a sodium lamp.

High pressure sodium lamps with low power are just right for greenhouses and greenhouses at any time of the year. They have power from 250 to 400 watts.

Such low power lamps have recently encountered a number of difficulties. The reason for this is:

Transition to small currents.
Transition to small diameters of the discharge tube.
The relative length of the electrode regions has been increased.

Consequences:

High responsiveness of sodium lamps to the power supply.
High responsiveness to deviations in the structural dimensions of the tube.
High responsiveness of the sodium lamp to the quality of materials.

Types of sodium lamps: low pressure, high pressure.

The production of high pressure sodium lamps results in:

Increasing requirements regarding compliance with the tolerance on the geometric dimensions of the nodes of the discharge tube.
The requirements for the purity of the material for manufacture are increasing.
The requirements for the accuracy of dosages of the filling element are increasing.

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Mercury free high pressure sodium lamps for plants

Recently, the whole world is fighting for the cleanliness of the environment. This is due to the fact that emissions of harmful substances into the atmosphere are increasing every year. Therefore, even in the production of lamps, there are rules - to make from elements that do not harm humanity. Even thermometers for measuring the body are beginning to be made from materials without the use of mercury.

In fluorescent lamps with a power of 40 W, the mercury content is reduced from 30 to 3 mg. In sodium products, it is not yet possible to exclude such a chemical element as mercury, since this metal helps the lamp to increase its efficiency in supplying light.

A sodium lamp for plants has such a feature during operation: when the service life approaches the end, the brightness of the light changes, as well as the shade. It becomes not yellow, but pink due to the fact that the composition of chemical compounds is changing. By the light, you can determine when you need to change it.

Modern sodium lamp manufacturers have come to the conclusion that dual burner products will produce the best results for several reasons:

Extended service life
Eliminates difficulty in instant re-ignition
Expanding the ability to combine sodium lamps of different powers
Expanding the ability to combine parts with different spectral compositions, etc.

A plus, of course, is the long life of the sodium lamp with two burners. However, there is one caveat. This is the correct use of the construct. It should be used evenly by one burner and the second. If only one works, and the second is, as it were, in reserve, then as a result, difficulties will arise in further work and the system will stop igniting normally.