They have recently appeared on the market and are very promising, but currently active use is limited by the high cost of the lamps. This variety is an analogue of DNAS, which has now been discontinued. Therefore, parallel connection is used to start low-pressure sodium lamps or metal halide lamps, designed to work with mercury ballast and do not require high-voltage starting pulses.
The spectrum is well suited for growing fruit-bearing plants. Galad electronic ballasts and connecting a HPS lamp
By the way, if anyone is interested, you can look at the lamp museum website in English, but with a bunch of pictures - there are countless different lamps collected here, including. Experts highlight the following characteristics and features of sodium lamps of the HPS type: The color rendering coefficient of the devices is very low, so they emit acrid yellow light, distort colors.
IZU is a thyristor continuous pulse generator. With a two-pin IZU Ignitors with two terminals are connected in parallel to the lighting device.
Although here it is worth mentioning that in reality there are a huge number of options for connecting a HPS lamp. Low-power light sources emit full luminous flux after 5 minutes, and higher-power devices - after 10 minutes.
According to authorities, ballast can be very hot - from 80 to degrees. Therefore, special gaskets are used to prevent this. HPS lamp with and without capacitor.
Ballasts for sodium lamps (HPS)
To ignite gas-discharge lamps, including sodium lamps, you will need specialized ballast equipment (ballast control equipment), because direct connection of HPS lamps to the network is excluded.
Ballasts for sodium lamps (HPS) include:
- IZU (pulse ignition device), which ensures the start of a gas-discharge lamp. At the moment it is turned on, the IZU transmits powerful high-voltage pulses to the electrodes, due to which a breakdown occurs in the gas mixture of the flask and the arc is ignited. After this, the issuance of explosive pulses stops, however, as does the influence of the pulse ignition device on the operation of the lamp;
- Throttle. Although electronic ballasts are considered more productive, their cost is much more expensive than pulsed ones. Therefore, the most common and in demand for connecting a HPS lamp is an inductive choke. The electric choke is presented in the form of a small block, which must correspond to the power consumption of the lamp. It limits and stabilizes the current supply, strongly resists any changes, maintains a decreasing current and prevents its increase, thereby ensuring long-term performance properties of the lamp and high luminous efficiency.
Thus, the ballast provides standard heating and efficient operation of sodium lamps for the entire period stated by the manufacturers.
Parameters and characteristics of the inductor
When choosing a ballast, you need to take into account its characteristics. One of the main parameters is inductance, which is measured in H (Henry). The amount of reactance of the switched on ballast depends on its inductance. This value characterizes the magnetic properties of an electrical circuit. 1Gn passes 1A of current at a voltage of 1V.
The main parameters of the inductive coil include:
- coil length in m;
- number of turns;
- permeability of the core material;
- cross-sectional size of the magnetic circuit;
- magnetic saturation.
The inductance of the ballast winding depends on all the characteristics described above.
The resistance of the coil winding turns depends on the cross-sectional area of the core. Therefore, when choosing ballasts for HPS, you need to take into account their power, on which the rated load current depends. Accordingly, the dimensions of the electric ballast depend on the power of the lamp.
Design
Lamps and lamps DNAT
When considering the design of a HPS lamp, we see the following elements:
- glass flask;
- cylindrical tube with aluminum holder.
The cavity of the tube is filled with mercury vapor (as in luminescent sources) and sodium vapor, forming a sodium amalgam. But these are not all gaseous substances: xenon is used to start the product.
Xenon is located inside the burner, which ensures a smooth start-up of the equipment. To increase service life, two burners can be used simultaneously.
Burner
The same cylindrical tube mentioned above. Made from transparent ceramics, resistant to high temperatures and chemically active substances. It was first manufactured by General Electric in 1960 and patented under the name “lucalos” (we know it as “polycor”). Its creation is based on the technology of sintering aluminum oxide at high temperatures. Tungsten electrodes are soldered to the two ends of the tube.
Inside it there is a mixture of inert gases and sodium amalgam under a pressure of 100 kPa and above, which makes it easy for an electrical discharge to occur due to the higher density of the medium, and also expands the region of the visible spectrum.
Base
To connect to the power lines, an Edison type E threaded socket is used. For HPS lamps with a power of 50, 70 and 100 watts, size E27 is used, for more energy-intensive models of 150, 250 and 400 watts - E40. The number indicates the diameter of the cartridge in millimeters.
How to select and check ballasts for lamps
Any starting and control device (electronic ballasts/electronic ballasts) must necessarily correspond to the power of the lamp. For example, to connect a 400 W lamp, you need a ballast of at least 400 W.
When choosing a ballast, also pay attention to which lamps it is intended for, since the same device is not always suitable for starting sodium (DNaT/DNaZ) and metal halide (DRI/DRIZ) lamps. Moreover, it also happens that the electronic ballast, as a whole, intended for igniting HPS, does not ignite this lamp when connected. Therefore, it is best to purchase electronic ballasts/electronic ballasts and lamps at a time and from a reliable store where good consultants work. And before purchasing, be sure to ask your consultant if there are any problems with the interaction of the devices you have chosen; as a rule, they are aware of such things. In addition, you can always ask the seller (either an online store or an offline one) to check and connect the lamp to the electronic ballast/electronic ballast before selling.
If you buy a lamp in one place, and electronic ballasts/electronic ballasts in another (for example, at a metal market or electrical equipment store), then you can find out whether they will work together only at home after the connection.
Connection diagram for a HPS lamp with a two-pin IZU
The connection diagram for the HPS lamp, which is shown in the first figure, is designed to contain a compensating capacitor connected in parallel to the power source. This is a dry type C capacitor, which is designed to compensate for the inductive component of the system - reducing reactive power consumption, reducing overall electricity consumption, as well as extending the service life of the finished product.
For example, to connect a HPS lamp with a power of 250 W (3A), a compensating capacitor capacity is provided (operating voltage indicators are 250V) of only 35 μF. This capacitance can be formed using several capacitors connected in parallel.
Sometimes capacitance indicators may be provided by the manufacturer, but an extremely large increase can lead to resonance in the circuit, and, consequently, to ineffective operation of the finished product.
If the HPS connection occurs independently, the permissible value of the location of the IZU should be taken into account. It should be located as close as possible to the base of the product, while the length of the connecting wires in this area should be minimal (the maximum permissible value is 1.5 m).
To ensure a high-quality and safe connection, high-voltage ignition wires for special purposes are used.
Decoding the abbreviation
The topic of this article will be devoted to consideration of the features of these lamps. But first, let’s decipher the abbreviation “DNaT” itself. What should be understood by this combination of letters? Actually, DNAT is a sodium arc tubular lighting source (naturally artificial). And when compared with other analogues, this variety has a higher efficiency. And it is as close as possible to 30%.
The question regarding the budget option has already been raised above - so in order to save money, it is worth purchasing high-pressure lamps. The light they emit allows one to distinguish colors over almost the entire range, with the exception of the short-wave spectrum. But how do these lamps actually work? More on this later.
Advantages and disadvantages
Spare lamps
Among the advantages of HPS lamps, the following items should be highlighted:
- High energy efficiency - the amount of light received from each watt of electricity consumed exceeds mercury arc sources and boldly competes with LED sources.
- Good efficiency - despite the high heating temperature, in comparison with halogen lamps and DRL lamps, HPS do not spend so much electricity on heating the space.
- The service life exceeds most gas-discharge and fluorescent lamps and is not inferior in duration to LEDs.
- They have a stable flow with a yellow spectrum of light that is pleasant to the eye, which makes the perception of the illuminated space comfortable.
- When recalculating the cost of a HPS light bulb per lumens produced, the price of the device is even cheaper than LED ones.
- Effective in street lighting in foggy conditions, since the light still provides fairly good visibility.
- The weight of the finished HPS lamp in comparison with other types of equipment is 10 - 15% lower.
However, in addition to the advantages, a number of disadvantages of this type of lighting equipment should be noted:
- Long acceleration time to rated power - on average it takes from 6 to 10 minutes for the tube to warm up to the stated parameters from the initial discharge.
- Low color rendering - in the lighting area you will hardly feel the difference between adjacent colors.
- They are explosive and toxic to humans - unlike low-pressure devices, they can easily fly apart and injure others, and mercury vapor in the tube can cause poisoning.
- They are not suitable for all tasks - for example, in some technological processes due to the pulsation coefficient or for growing certain types of crops.
- Over time, they can burn out, which is why the light changes its spectrum and the power of the bulb.
Why is it necessary?
DNAT lamps are old and time-tested light sources that emit intense light at a minimum power level. They are actively used in street and greenhouse lighting. Due to insufficient color rendering and strong flickering, they are not used in lighting living rooms.
IZU for DNAT
To connect the DNAT, you need to use a special IZU triggering device with a ballast and a capacitor. The first is required to create a high voltage pulse and form an arc. At the same time, it must be selected taking into account the power of the light source up to 400 watts.
Increasing the DNA voltage as a function of the IZU
Advantages and disadvantages
Development of methodological material on the topic: “gas discharge lamps”
If you can’t decide whether to buy HPS or LED lamps, then you need to consider the pros and cons of sodium devices. Then you can weigh the pros and cons to make the right choice.
The positive properties of sodium light sources include their high luminous efficiency, long service life, and low energy consumption. In addition, they have a high efficiency and are resistant to temperature changes.
However, HPS requires time to start (5 - 10 minutes), they have poor color rendering and distort colors, which cannot be said about LEDs. The disadvantages of the lighting element include frequent flickering of the lamp, which leads to eye fatigue.
The advantages and disadvantages of HPS lamps will be discussed in more detail below.
pros
Experts highlight the following positive characteristics of HPS lamps:
- Sodium light sources emit a powerful luminous flux (up to 160 Lm/W for high-pressure lamps, approximately 200 Lm/W for low-pressure modules). These figures are higher than other types of sodium devices and ice lamps.
- Long service life - from 10,000 to 30,000 hours. At the same time, the quality of lighting does not decrease.
- HPS consume a minimal amount of electricity, which consumers cannot help but rejoice at. According to this indicator, DNAT is ahead of DRL.
- Light sources operate correctly at temperatures from -60 to +40. The lamp starts even at low temperatures.
- The efficiency of the HPS lamp reaches 30%.
Depending on the level of internal pressure of saturated sodium vapor, HPS with high and low pressure is isolated. The former show higher indicators, and the latter – low.
A low pressure sodium lamp (LPNS) has all the advantages described above. It is used only for background lighting of streets, as it emits a pungent orange color.
High-pressure sodium lamps (HPS) have better color rendering, which allows them to be installed in gyms and industrial premises. In addition, the lighting element has high luminous efficiency with minimal voltage and a long service life. High pressure sodium lamps start up faster than low pressure sodium lamps.
Minuses
In addition to the positive characteristics, HPS lamps have negative properties:
- Low color rendering, especially for low pressure modules. They distort colors, which prevents their use in residential areas.
- Temperature limitation. Despite the characteristics declared by the manufacturer, the operating temperature of DNAT is in the range from -20 to +30°. If this condition is violated, the device will fail faster and the light output will decrease.
- Sensitivity to changes in electricity. Such light bulbs are recommended for use in networks with stable voltage. Although a high-quality throttle can correct this shortcoming.
- Long on time. After starting, the light glows weakly, maximum light output is observed after 5 - 10 minutes.
- Strong current ripples (up to 50Hz). For this reason, the device is not recommended for lighting homes and industrial premises. Frequent flickering tires the eyes.
HPS lamps contain toxic mercury, so they must be disposed of in a special way. A failed device must be taken to special organizations that deal with hazardous waste.
Scope of application
HPS lamps are ideal for lighting greenhouses, as they emit monochrome yellow light that is favorable for plants.
Sodium vapor modules, due to poor color rendering accuracy, are not intended for use in everyday life; most often they are installed to illuminate streets and personal plots, as well as avenues and highways .
HPS lamps are installed in electrical equipment intended for illumination and background lighting:
- In greenhouses, winter gardens and greenhouses to ensure the basic yield of cultivated plants, as well as to increase their growth rates.
- Container sites, sports facilities and tunnels.
- Warehouse and production facilities, workshops, where the quality of color rendering does not play a big role.
- Architectural structures and historical monuments.
- Airports, railway stations, etc.
In all of the above cases, sodium lamps provide adequate illumination with minimal energy consumption.
Operating principle and connection diagram of a HPS lamp
An arc discharge is maintained inside the torch. For its appearance, IZU is used. This abbreviation stands for pulse ignition device. When the circuit is turned on, the lamp receives a pulse from 2 to 5 kV. It is needed to start the lamp - electrical breakdown of the burner and the formation of an arc discharge. The ignition voltage is significantly higher than the combustion voltage. Typically, three to five minutes of energy are spent to heat up the burner. At this moment the brightness is still low. Returning to normal operating mode takes no more than 10-12 minutes, while the brightness increases and normalizes. In the diagram, L is phase (line), N is zero.
The circuit contains an IZU and an inductor as a ballast element. Usually the connection diagram is present on the body of the throttle and/or pulse ignition device.
Sometimes a non-polar capacitor may be added to the circuit. Typically a capacitance of 18-40 µF is used. It is not necessary; adding it will not make the lamp shine brighter. Its task is phase compensation. The fact is that the circuit consumes active and reactive power, since there is a choke. There is no benefit from the reactive component, but the harm is obvious - interference in the power supply and reduced energy efficiency. However, adding capacitance to an electrical circuit will not improve energy efficiency. Adding a capacitor will somewhat reduce inrush currents and prevent irreversible degradation of the electrodes.
The capacitor used is selected based on the power of the lamp. Recommendations are presented in the table.
| HPS lamps | |
| Lamp power, W | Parallel connected capacitor 250 V, µF |
| DNAT-70 1.0A | 10 µF |
| DNAT-100 1.2A | 15-20 µF |
| DNAT-150 1.8A | 20-25 uF |
| DNAT-250 3A | 35 µF |
| DNAT-400 4.4A | 45 µF |
| DNAT-1000 8.2A | 150-160 uF |
When assembling a lamp using HPS lamps yourself, it is not advisable to use a wire longer than one meter between the socket and the igniter.
NLVDs are very sensitive to the quality of the power supply. When the voltage drops by 5-10 percent, the luminous flux can drop by a third. Increased voltage significantly reduces service life.
The IZUs for dnat (pulse ignition devices) themselves can have either two or three contacts. There's no difference. Not one of these options is worse or better than the other - both provide the same operating conditions for the lamp.
There is also a type of lamps that do not require an IZU. This is DNAS. They can be recognized by the starting antenna near the burner. It is usually made from one or two turns of wire that wraps around the burner.
Technical parameters of the IZU
When buying a pulse ignition device, you need to know the value of the maximum permissible current, the maximum frequency pulse voltage, voltage, automatic shutdown function of the device and the maximum cable length. The permissible current should not exceed twice the operating current, the maximum frequency pulse voltage should not be up to 3.5 kilowatts at the output. In the event of a device failure, the pulse ignition device must have an automatic shutdown function. The maximum cable length should be about 2-3 meters.
Specifications
High Pressure Arc Lamps
Increasing the pressure of the medium in which the electric charge propagates and a luminous arc occurs makes it possible to obtain a more intense luminous flux, spending less energy. For example: the light output of low-pressure sodium lamps does not exceed 100 lumens per watt, while for high-pressure sodium lamps this value is more than 200 lumens per watt. Therefore, they are used for outdoor lighting or in large areas - greenhouses, hangars, production workshops.
The fundamental design of mercury and high-pressure sodium arc lamps has many similarities, but there are also differences, due to which the connection diagram of a sodium lamp is different from that of a mercury lamp. And they are not interchangeable. These lighting devices can be distinguished from each other both by designation and appearance. DRL – mercury arc lamp, DNaT – sodium arc tube lamp. And the external differences will become clear to you from analyzing their structure. So, they consist of the following elements:
- Gas burner.
- Set of electrodes.
- External flask.
- Base.
Gas-burner
In both cases, it is made in the form of a tube made of heat-resistant quartz glass. But in DRL its dimensions are larger than in DNAT. Due to the high chemical activity of sodium, aluminum alum – Al2O3 – is added to the burner glass. An inert gas - argon - is pumped into the burner at a pressure of 100-150 kPa. There is also mercury or sodium amalgam (an alloy of Na and Hg).
Electrode set
DRL lamps have four of them: two main and two ignition. The pairs are located at opposite ends of the flask and connected to different poles of the supply line. But DNAT has only two electrodes. This causes differences in the starting method and the construction of the lamp connection diagram.
With mercury light sources, the arc lights up from a small spark that occurs between electrodes of opposite sign. And sodium requires an igniting impulse. Moreover, the DRL of the first releases (until the mid-60s of the last century) had two electrodes and used the same switching principle, but later it was abandoned.
External flask
This is the main visual distinguishing feature of lamps. There is a vacuum inside the flask, which ensures the chemical and thermal stability of the burner glass. But with DRL it is white or matte, and the HPS flask is transparent.
A layer of phosphor is applied to the inner surface of the mercury lamp bulb. The fact is that the combustion of mercury vapor causes a deathly green or blue glow, which extremely distorts the perception of reality by the human eye. The phosphor shifts its spectrum into the region of dazzling white light, which is quite acceptable for street lighting.
Sodium lamps glow red or bright orange. Light rays of this frequency are practically not refracted by water suspension that can hang in the air (snow, fog, drizzle, splashes), so it is used to illuminate highways. There is no need for a spectral shift, so the bulb is transparent.
Base
Both lamps use a so-called Edison threaded base, designated by the letter E, to connect to the supply line. Since the power of high-pressure arc lamps usually exceeds 250 W, E40 models with a diameter of 400 mm are used. For the same reason, it is recommended to use ceramic cartridges that can withstand high heat.
Appearance
The principle of operation of the ballast is based on the coil’s ability to self-induct. In fact, a ballast is an inductance coil, inside of which there is a core with a metal frame. This frame consists of steel and ferromagnetic plates that are insulated from each other. This is necessary to prevent the formation of eddy currents, which cause interference. The top of the device is covered with a casing.
Electronic ballasts have become very popular lately. They look like compact blocks with terminals exposed. The basis of the device is a printed circuit board, which is placed in a plastic box.
All chokes have an external resemblance to transformers. The number of pins they have can be different, so it is difficult to identify them only by appearance. To do this, you need to pay attention to the image on the device body.
Operating principle and connection diagram of DNAT
The principle of operation of sodium sources is the breakdown of the gas gap between two electrodes inside the discharge tube.
Rice. 2. Operating principle of a HPS lamp
To do this, a high voltage is applied to the spark gap - in the range from 2 to 5 kV, which should be sufficient for instant breakdown. However, it is impossible to ensure breakdown from a household network, so starting, as in other gas-discharge lamps, occurs using a ballast (ballast). Today, in practice, two types of ballasts are used for arc sodium and mercury gas-discharge lamps - electronic and electromagnetic.
The ballasts for gas-discharge lighting sources include three components:
- choke-transformer - to limit a sharp increase in the current curve flowing in the circuit, it allows you to build the parameters of electrical quantities in accordance with the characteristics of the HPS lamp;
- pulse ignition device (IZU) - designed to briefly increase the voltage to a value sufficient to produce a discharge that ignites a tubular lamp;
- capacitor - is not a mandatory component, but allows you to compensate for the voltage vector biased by the inductor.
Today you can find several options for HPS connection diagrams, which differ both in the characteristics of the components and in the factory features of the lighting devices. Therefore, all circuits for switching on a lighting source can be with or without a capacitor; the IZU can have a two-pin or three-pin connection. Let's look at them in more detail.
Rice. 3. Connection diagram with a two-pin IZU
As you can see, this method of starting sodium light bulbs involves parallel connection of the IZU in relation to the load. But at the same time, a high potential is also supplied to the inductor, which over time will lead to deterioration in performance and subsequent breakdown of the insulation. Moreover, modern single-winding chokes have only weak impregnation without a paper layer. Therefore, this HPS connection scheme is relevant for low voltage sodium tubular models.
Rice. 4. Connection diagram with a three-pin IZU
This circuit does not have the disadvantages of two-pin IZUs, since the HPS lamp has a separate high-voltage output from the IZU, which is separated from the connection point to the inductor. Please note that in any circuit the inductor must be connected to the phase conductor, otherwise the sodium lamp will fail in the event of a short circuit.
With a three-pin circuit, it is important to correctly observe the polarity of the IZU markings:
- B – connects to the ballast (throttle);
- Lp – phase output to the high pressure lamp;
- N – to the zero terminal of the lamp and network.
In addition, a circuit with a capacitor connection can be used:
Rice. 5. Connection diagram with capacitor
As you can see in the diagram, together with the use of an IZU, a capacitor located before the ballast transformer is connected in parallel to the consumer in the HPS lamp circuit. This circuit compensates for reactive losses that do not relate to the quality of the light flux.
In addition, to protect the HPS lamp in its power supply circuit, you can install protection with a fuse or circuit breaker.
Disposal
Sodium, by its nature, is a volatile substance and, in contact with air, can ignite rapidly. For this reason, sodium light sources should not be disposed of as regular waste. Like any energy-saving lamp that contains mercury, they also need to be disposed of in special containers
If you cannot dispose of HPS sodium lamps yourself while observing safety precautions, you should call a special service
Gas-discharge arc sodium lamp DNaT is used to illuminate large areas, city streets, and greenhouses.
Do not confuse low and high pressure sodium lamps. They have different designs and operating principles.
The emission spectrum of both is dominated by orange light. For low-pressure products, the radiation is almost monochrome; they shine with a bright golden light.
If they are used for lighting in rooms, the colors will be practically indistinguishable.
In high-pressure lamps the spectrum is more diverse.
In those models that are used in greenhouses for growing plants, a little blue light is specially added to the light spectrum.
The kit for connecting a high-pressure lamp includes several components, without which you simply cannot start it. That is, simply by applying 220 volts to it, it will not light up.
To do this, you need a special device - a choke or ballast, which in turn is connected according to a certain circuit.
This diagram is often depicted directly on the body.
Here is a more detailed drawing of it.
Painted on it:
the inductor itself (ballast), to which the phase is supplied
then this phase is supplied to the pulse ignition device - IZU
Through it you can connect instances of different power, from 70 to 400W.
The IZU creates a starting impulse for the breakdown of the burner contents in the flask and the formation of an arc. The voltage reaches several thousand volts!
And the burner itself heats up to 1300 degrees during operation.
Only after the IZU is the gas-discharge lamp itself connected.
The same connection diagram can be depicted on the walls of the ignition device.
In addition, it is recommended to use a capacitor in the connection kit. Although it is not present in all schemes.
Why is it needed? As is known, circuits using power chokes consume both active and reactive power. From the second, you will not get any beneficial effect.
This will not make the lamp shine brighter, but the losses will increase. It is in order to remove this reactive component that a phase-compensating capacitor is used.
A visual comparison of the current consumption of a HPS lamp with and without a capacitor:
As you can see, more than double the difference. In the first case, the compensated current (active) is shown, and in the second case, the full current (without a capacitor in the circuit).
Some people think that by doing so they also reduce energy consumption, but this is not entirely true.
Your meter is not designed to count reactive or apparent energy, and the actual cost savings can be a maximum of 3-4%.
But you will eliminate unnecessary losses due to heating of wires and iron.
Here is a compact shield assembled with your own hands, according to the connection diagram.
You can, of course, assemble all this in the overall body of the lamp, if the dimensions allow.
It is very important, before assembling such a circuit yourself and using any components, using a conventional multimeter in the maximum resistance measurement mode, check the insulation of the inductor and capacitor. Is there a hole in the body? Is there a hole in the body?
Is there a hole in the body?
To supply and disconnect 220V power, use a two-pole input circuit breaker.
For one lamp with a power of up to 400W, a machine with a nominal value of 5-6A is quite suitable. In addition to on-off switching operations, it will also play the role of a protective device.
A circuit breaker is mounted at the very beginning of the circuit. Do not forget to also ground the entire panel body.
Two neutral wires come out of the machine. According to the diagram, one of them is connected directly to the lamp, and the second one is connected to the corresponding terminal labeled “N” on the starter.
Otherwise, you can accidentally burn the product if during operation the neutral wire after the ballast choke accidentally shorts out.
And connect the wire from the output contact to terminal “B” (Balast) of the ballast.
After that, connect the middle terminal Lp (Lampa) to the light bulb socket.
Please note that there are two-pin and three-pin IZUs. The first ones are connected in parallel with the lamp itself.
Device
According to the established abbreviation DNaT, these are (D - arc, Na - sodium, T - tubular) devices. Based on their operating principle, they belong to high-pressure lighting equipment. Structurally, HPS lamps are a glass bulb with a base, usually E27 or E40.
Rice. 1. Design of a HPS lamp
The internal structure consists of:
- discharge tube - made of aluminum oxides and designed to burn an arc inside the lamp;
- electrodes - designed to start the discharge, which is why they are made of molybdenum;
- gas mixture - acts as a medium for generating light radiation, the main percentage here is occupied by sodium vapor, but argon is included as an impurity to accelerate combustion, and mercury to ensure high light output.
The flask is made of heat-resistant glass, since the gas in the tube can heat up to 1300ºС, as a result of which the HPS lamp itself on the surface will have from 100 to 400 ºС. A vacuum is installed inside the lamp for better light output.
Design and assembly of ballasts (ballasts) for HPS
HPS chokes are divided into low-frequency and high-frequency. In the first case, the inductor delays low-frequency current, and in the second, high-frequency current.
A ballast for low frequency current consists of a coil, inside of which there is a steel core, and its plates are insulated from each other. The inductance of such a device is from 1 H. This property allows it to limit the voltage if it decreases or increases.
High-frequency chokes for HPS do not have a core. In such devices, copper wire is wound onto a plastic frame or resistor. This ballast looks like sectional (multilayer) winding.
The core material affects the size of the HPS choke. The magnetic bar is usually located inside compact devices. However, size does not affect their inductance.
High-frequency devices are equipped with ferrite or steel cores. Such ballasts are used in a wide frequency range.
Depending on the installation location, built-in and closed chokes for HPS are divided. The former are inserted into the housing of lighting fixtures, which protect them from moisture, while the latter are mounted in a sealed unit.
Advantages and disadvantages
DLR is a high-pressure mercury arc fluorescent lamp, to which a special type of phosphor is added. Available in power ratings from eighty to one thousand watts. It has a color temperature of 3800 K. Efficiency is estimated at 40 lumens per watt. Works for 10 thousand hours. Has low color rendering.
DRL 250
Widely used for general street lighting, industrial workshops and any uncrowded places. That is, its main use is where color rendering is low and energy saving is high. The main advantage of such lamps is their high efficiency. Among the disadvantages, we can note the fact that ozone is released very intensively, ignition when turned on takes 7 minutes, re-ignition is possible after twenty minutes. In addition, in this lamp it is necessary to turn on the ballast choke, and the concentration of mercury vapor is sufficient to poison a person if the bulb is damaged.
The high pressure sodium tube arc lamp is an economical luminaire that is used for outdoor lighting. It is found on the street, highway, tunnel, train station, airport and industrial area.
The advantage lies in its efficiency, high luminous efficiency (efficiency is 30%) and a long service life - from 12 to 25,000 hours. One of the disadvantages is the rather long ignition time.
Note! In addition, such a lamp does not work well in bad weather conditions. High efficiency of light flux from DRL lamps
High efficiency of light flux from DRL lamps
Features of installation and operation
The most common ballast devices are ballast inductive chokes, which limit and stabilize the current.
The connection diagram for sodium lamps involves supplying supply voltage to the terminals of the lamp. If you connect the NL yourself, it is recommended to use a wire connecting the ballast to the sodium lamp, no more than 1 m long. The use of cotton gloves is also recommended.
When used for artificial lighting of plants, NLs are located no closer than 50 cm from them. Power can be from 75 to 400 W. However, in the case of a power of 400 W, the distance to the plants should be increased to 1.8 - 2 m
Compliance with these conditions is important in order not to damage the plants
A sodium lamp (usually an outdoor one) must be reinforced with a protective glass bulb to avoid damage due to differences in the internal temperature of the bulb and the external environment.
The quality of NL light also depends on their timely cleaning from dust and dirt. To do this, you can use a cloth moistened with alcohol.
Disposal of NL by special institutions is mandatory in order to avoid environmental pollution with mercury vapor (if contained), as well as to prevent an explosion of sodium gas that can occur when it comes into contact with oxygen.
Recommendations for the use of DNAT
When operating HPS lamps, it should be remembered that the temperature of the outer bulb reaches several hundred degrees. Therefore, it is under no circumstances acceptable to handle it with bare hands immediately after turning it off or while it is glowing. Otherwise, you may get serious burns; you must wait for a lower temperature.
When replacing a HPS lamp, it is important not to touch the glass surface with unprotected palms, as fingerprints will remain on it. Over time, the fat will begin to burn and this can lead to premature cracking of the flask. If you do handle it with your bare hands during installation, you should wipe the surface with paper or cloth.
Rice. 7. Burning hand marks on the lamp bulb
During operation, do not allow directed streams of water to come into contact with the light bulb, as the red-hot bulb will simply crack from such interaction. But you shouldn’t worry about a few drops or aerosols when watering; modern HPS has special glass and is resistant to such little things.
If the light from a regular HPS is not enough for you or the technical characteristics of the standard model do not suit you in some way, you can take an improved lighting device, for example, a HPS lamp.
What are the possible connection errors?
When connecting, the ballast on the four contacts may be installed incorrectly. To prevent this mistake, you need to use the connection diagram for Dnat 400 with a capacitor.
Incorrect connection of the four-pin choke
Cracks may appear on the device body as a result of installing the source with bare hands. To avoid this, wipe the lamp with a clean cloth before starting it up.
A choke from an arc mercury phosphor source can also be used when using a different type of ballast. Then the lamp will be unusable. To prevent this from happening, you need to select the inductor based on the type of lamp. Technical parameters will help for this.
Technical characteristics of DNA lamps
In general, an IZU is a device aimed at increasing the voltage to several kilovolts to form an arc. The equipment has a two-pin and three-pin design. The IZU produces high voltage pulses for efficient operation of a high pressure sodium lamp.
Source
Operating principle
For an electric charge to occur in a gaseous medium, a high voltage pulse is required. Since sodium melts at a fairly high temperature, the electric charge ignites slowly: low-power HPS produces a full luminous flux after 5-6 minutes, and high power - after 10-15 minutes.
At the moment of startup, the environment is cold, its electrical resistance is low, so the process is accompanied by an avalanche-like increase in current in the circuit, which can cause overheating and destruction of the lamp electrodes. Therefore, the DNAT control gear includes an electronic ballast (choke) - an inductor without a core. Compensation occurs due to the emergence of a magnetic flux directed opposite to the current that generated it.
Launch of DNAT
So, the ballast uses only three components:
All components can be found on sale in electrical markets. The components are of both domestic and foreign (Israel, Germany) production. On the Internet, as usual, they criticize domestic ones and praise imported ones.
The ballast circuits look like this:
When assembling and using these circuits, you need to pay attention to which wire the phase is supplied through. Studying materials on the Internet, I came to the conclusion that this is an important point (if I’m wrong, correct me in the comments). Solving this issue, I marked the plug and socket, indicating the phase on them.
It is also convenient to use the colors of the wires when assembling the circuit. This speeds up installation and eliminates the need to call them. The rules are:
To connect three wires at one point (zero from the lamp, from the IZU and from the plug), it is convenient to use a three-pin terminal block.
This is what my assembled ballast for DNAT 250 looks like:
Precautions for use
The outer bulb of the lamp heats up to a temperature of 250–300 degrees. Celsius. This determines the list of safety measures when working with it.
- Do not touch the lamp bulb for 10–15 minutes after turning it off.
- You should absolutely not touch the flask with your hands without gloves: traces of sweat and grease on the surface will lead to uneven heating and even an explosion.
- Provide good ventilation for the lamp and keep it away from flammable structures. The same applies to the ballast choke, which heats up to 150 degrees. Celsius.
In addition, protect the lamp from impacts: when the bulb explodes, the fragments fly over a very long distance. If the burner is damaged, the room or area may be contaminated with mercury.
