Many gardeners often use artificial lighting to grow seedlings at home. But how to do it as high quality as possible? Indeed, for the full development of plants, they need a certain range of lighting. In addition, I want to do with minimal material costs. For this, it is worth paying attention to luminaires with DNaT lamps (the connection diagram will be discussed in this article). But in addition to the domestic sphere of application, such lighting sources are good in use in other areas, including various industries.
Decoding abbreviations
The topic of this article will be devoted to consideration of the features of these lamps. But first, we will decipher the very abbreviation “DNaT”. What should be understood by this combination of letters? Actually DNaT is an arc sodium tube light source (naturally artificial). And when compared with other analogues, this variety is characterized by a higher efficiency. And it is as close as possible to 30%.
The question has already been raised above regarding the budget option - so in order to save money, it is worth buying high-pressure lamps. The light emitted by them allows us to distinguish colors over almost the entire range, with the exception of the short-wave spectrum. But, actually, how do these lamps work? More about this later.
Principle of operation
We have already read the decoding of the abbreviation of the DNaT lamp, now it's time to understand the principle of its operation. Everything is based on arc discharges that form in the so-called “burner”. This is a cylindrical discharge tube made of pure aluminum oxide. It is placed in a glass and transparent container. At its end is a threaded base type E-27 or E-40.
The internal cavity of the burner is filled with a mixture of mercury and sodium vapors with a small inclusion of xenon ignition gas. Like any other discharge lamp, the DNaT type requires a pulsed starting device (IZU) and ballast (inductor) to connect.
In short, the operation of the sodium lamp can be represented as follows: after its inclusion, the IZU delivers high-voltage electrical pulses (of the order of several kilovolts). As a result of the action of these pulses, an arc arises. The need for a throttle in the DNaT connection diagram is to stabilize the voltage and maintain it in the right mode for the lamp to work properly.
Features of sodium lamps like DNaT
It is worth noting that immediately after turning on the sodium lamps, they burn dimly and weakly, since the main resources are spent on heating the burner. Only after 5-10 minutes does the luminous flux acquire the necessary parameters of brightness, strength and saturation. At this point, the temperature inside the burner reaches the required value.
In addition to DNaT lamps with a separate IZU connection, there are varieties on sale where this device is already part of the design. And in this case they are marked already a little differently - DNaS. As a rule, companies such as Osram and Philips are engaged in such production.
At the same time, there are other features that everyone needs to know about.
Specific radiation
This is the main distinguishing feature of DNaT lamps - they have a rather specific glow of a yellow-orange hue. And since there is sodium inside the burner, their radiation takes on a monochrome character with a high degree of pulsation.
Because of this, color rendering is disturbed. For this reason, the connection diagram of a luminaire with DNaT lamps does not find application in residential buildings, including office, industrial and educational premises.
Light output
Among many other types with the worst indicators of the quality of the luminous flux, DNaT lamps favorably differ from them in terms of light output. This indicator reaches values up to 100 lm / W. At the same time, this is characteristic only of new sources of lighting. By the end of its service life, this figure is significantly reduced - almost twice!
The quality of the glow, including the duration of the lamps, largely depends on the conditions of their operation. According to manufacturers, the service life can be up to 10,000 hours. However, this is achieved by observing a certain temperature regime during the operation of the lamps - from -30 to +40 degrees. Moreover, using IZU of high quality performance.
Cycling does not fit
Due to the design features of sodium lamps (meaning the ignition system), the DNaT connection diagram is not suitable for lighting systems with frequent on and off cycles.
Before the next "launch" they need a long "rest" - about 3-6 hours, no less. This is especially true for domestic products.
Power indicators
As for this parameter, it varies in the range from 75 watts to 1 or more kilowatts. It is only worth considering that during the operation of the lamp can become very hot. In this regard, for the field of crop production should choose a rated power of 75 to 400 watts. Stronger lamps can simply burn the delicate foliage of greenhouse plants.
By virtue of strong heating, such light sources need special lamps. They will serve as reliable protection against pollution and direct moisture, and on the other hand, they will help to supply the right amount of air for cooling.
Application area
As was marked at the very beginning of the article, sodium lamps are widely used in addition to household purposes. Due to their high efficiency and good benefits, they can be used in almost any field of human activity. Often, such lamps are placed on street lighting fixtures in various public places:
- Streets with pedestrian crossings;
- squares and parks;
- highways;
- construction sites;
- Airports
- tunnels.
The glow of DNaT lamps does not cause eye fatigue for drivers, which is very important, since the driving conditions of all cars depend on this. Fatigue and driving are not compatible with each other.
In addition, the use of these light sources improves visibility in bad weather. Due to the powerful light flux, the negative effects of fog are eliminated, all illuminated objects have increased contrast.
High-pressure sodium lamps (they are also DNaT) are relevant for street lighting fixtures, as well as for large-area premises - sports halls, production and shopping complexes.
Most greenhouses began to use such light sources for additional lighting. And in this regard, manufacturers began to produce DNaT lamps, which have a special radiation spectrum that plants need for their proper development.
Features of installation and connection
Despite the fact that sodium lamps are widely used, they are mainly used in the organization of street lighting. This is due to insufficient transmission of the color spectrum. At the same time, there is not much difference in which position the lamps will be. At the same time, as long-term practice shows, their most effective position is horizontal. In this case, the main light flux is radiated in different directions.
For the correct connection of lamps, as we now know, one cannot do without the help of third-party "equipment". We are talking about ballast or in another way - a throttle for DNaT, as well as a pulse starting device (IZU). Without this, the sodium lamp will simply refuse to start. They have already been mentioned, but now it's time to get to know them better.
Control gear
In fact, this is a bunch of two main devices - ballast (throttle) and IZU. Without a doubt, electronic ballasts are the best of their kind, unlike inductive devices. However, they lose to them in terms of cost - they are quite high. For this reason, ballast inductance reactors are much more widespread. In some lamps they are already included in the device. That is, it remains to apply voltage to the terminals.
At present, double-wound chokes are already outdated and in this regard, it is worth paying attention to single-wound types. In this case, the ballast should be designed specifically for light sources such as DNaT and have the same power as the light sources themselves.
At the same time, in the wiring diagram of the DNaT lamp through the inductor, the original (that is, "native") ballast must be present. Otherwise, no one can guarantee full operation, including their service life. Or the light output of the lamps can be significantly reduced.
Other situations cannot be ruled out either. For example, the effect of “blinking” - when the lamp can go out immediately after heating, and after cooling down the whole process is repeated again.
Pulse ignition "apparatus"
This is the very device with which the sodium lamp is launched. Different manufacturers produce IZU with both two and three conclusions. Because of this, the connection schemes of gas discharge lamps are also different. As a rule, it is already shown on the IZU buildings. From domestic devices it is worth taking a closer look at the UIZU - it is suitable for lamps of different capacities and can be combined with all types of ballasts.
PRA for DNaT (UIZU) can be located in the immediate vicinity of the ballast and near the lamp itself, by connecting to its contacts. Moreover, the polarity does not play a special role. However, it is recommended that you connect the red hot wire to the ballast.
Capacitor inclusion
Discharge arc sodium lamps are reactive power consumers. For this reason, sometimes (in the absence of phase compensation) it makes sense to include a noise suppression capacitor in the DNaT connection circuit. Its presence will reduce the starting current and avoid unpleasant situations.
Depending on the characteristics of the chokes used, the capacitance of the capacitor should be appropriate:
- DNaT-250 (3 A) - 35 uF.
- DNaT-400 (4.4 A) - 45 uF.
In this case, preference should be given to dry-type capacitors that are capable of working with a rated voltage of 250 V.
As for the connection of the capacitor in the connection diagram of DNaT 400 with the IZU, it should be performed with a thick stranded wire with a large cross section. The cable itself must also withstand the load of a rather weak current. Use a reliable solder or terminal block, and the screws should be tightened with moderate force so as not to damage the latter.
Wiring diagram
As we now know, the wiring diagram for sodium lamps mainly depends on the number of terminals of the IZU (2 or 3). The inductor, as can be judged from the circuit (in the body of the article it can be found), is connected in series to the mains, while IZU - in parallel.
In other words, the phase first enters the electromagnetic ballast, then goes to the IZU and only then to the lamp. The ignition device itself may have zero in the case of three leads.
It is worth recalling once again that the power of the ballast must fully correspond to the same indicator of the lamp. This is especially true for the use of electronic ballasts for lamps. Also in the circuit there may be a capacitor in order to reduce reactive power (this has already been described above).
Connecting sodium lamps requires certain knowledge and skills. Especially when it comes to their industrial application. If the work is done independently, it is necessary to take into account an important point - the length of the wires that connect the ballast to the lamp should not exceed 1-1.5 m.
Precautionary measures
If the connection of lamps like DNaT is carried out independently, you need to make sure that it is observed in accuracy. The drawing is on the ballast housing or the IZU, but in its absence it is worth consulting with a specialist or seller. The consequences of an incorrect connection are simply disastrous:
- failure of one of the circuit elements;
- knocking out traffic jams;
- lamp burst;
- fire.
Due to grease or other contaminants, the light source may burst due to uneven heating immediately after entering the operating mode. For this reason, the flask should not be touched with bare hands, it is better to work with gloves. After installing the lamp in the cartridge, wipe it with alcohol. This will remove pollution.
If drops of any liquid fall on a working lamp, this will inevitably provoke an explosion. The probability is 100%! It is also worth installing the lamp so that it does not fall during operation. And every 30 days it is necessary to wash the dust from it.
Thinking about the implementation of the DNaT connection scheme, it is worth considering that it is recommended to change sodium lamps after 4 months or six months. With their further use, light output decreases noticeably.