Many gardeners often use artificial lighting to grow seedlings at home. But how can you do it in the best possible way? Indeed, for the full development of plants, they need a certain spectrum of lighting. In addition, I want to get by with minimal material costs. To do this, pay attention to lamps with HPS lamps (the connection diagram will be discussed in this article). But in addition to the domestic scope, such light sources are good for use in other areas, including various kinds of industry.
Deciphering the abbreviation
The topic of this article will be devoted to the consideration of the features of these lamps. But first, let's decipher the abbreviation "DNaT" itself. What is meant by this combination of letters? HPS itself is an arc sodium tubular light source (naturally artificial). And when compared withother analogues, then this variety has a higher efficiency. And it is as close as possible to 30%.
The question of the budget option has already been raised above - and so, in order to save money, it is worth buying high-pressure lamps. The light emitted by them allows you to distinguish colors in almost the entire range, with the exception of the short-wave spectrum. But how do these lamps actually work? More on that later.
Working principle
We have already familiarized ourselves with the decoding of the abbreviation of the HPS lamp, now it's time to understand the principle of its operation. Everything is based on arc discharges, which are formed in the so-called "burner". This is a cylindrical discharge tube, which is made of pure alumina. 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 vapor and sodium with a small inclusion of xenon ignition gas. Like any other gas-discharge lamp, the DNaT type requires a pulse starting device (IZU) and a ballast (choke) to be connected.
In short, the operation of a sodium lamp can be represented as follows: after it is turned on, the IZU delivers high-voltage electrical impulses (of the order of several kilovolts). As a result of the action of these impulses, an arc occurs. The need for a choke in the HPS connection circuit is to stabilize the voltage and maintain it in the desired mode for the full operation of the lamp.
Features of HPS sodium lamps
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 the light flux acquires the necessary parameters of brightness, strength and saturation. At this point, the temperature inside the burner reaches the required value.
In addition to HPS 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 a little differently - DNAS. As a rule, such production is carried out by companies such as Osram and Philips.
At the same time, there are other features that everyone would like to know about.
Special Radiation
This is the most important distinguishing feature of HPS 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, the color rendering is broken. For this reason, the scheme for connecting a luminaire with HPS lamps is not used in residential buildings, including office, industrial and educational premises.
Light output
Among the many other types with the worst luminous flux quality, HPS lamps compare favorably with 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 light sources. By the endservice 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 subject to a certain temperature regime during the operation of the lamps - from -30 to +40 degrees. And with the use of high-quality IZU.
Recurrence is not suitable
Due to the design features of sodium lamps (meaning the ignition system), the HPS connection scheme is not suitable for lighting systems with frequent on and off cycles.
Before the next "start" they need a long "rest" - about 3-6 hours, no less. This applies in particular to domestic products.
Power Ratings
As for this parameter, it ranges from 75 watts to 1 or more kilowatts. It is worth considering that during operation the lamps can become very hot. In this regard, for the field of crop production, you should choose a rated power from 75 to 400 watts. Stronger lamps can simply burn the delicate foliage of greenhouse plants.
Due to the strong heating, such light sources need special lamps. They will serve as a reliable protection against pollution and direct moisture, and on the other hand contribute to the supply of the right amount of air for cooling.
Scope of application
As inAt the beginning of the article, it was noted that 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 these lamps are placed on street lighting fixtures in various public places:
- streets with pedestrian crossings;
- squares and parks;
- roads;
- construction sites;
- airports;
- tunnels.
The glow of HPS lamps does not cause eye fatigue for drivers, which is very important, since the driving conditions of all cars depend on it. Fatigue and driving are incompatible concepts.
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 HPS) are relevant for street lighting fixtures, as well as large areas - gyms, industrial and shopping complexes.
Most greenhouses have begun to use such light sources for additional lighting. And in this regard, manufacturers began to produce HPS lamps with a special radiation spectrum that plants need for their proper development.
Features of installation and connection
Despite the fact that sodium lamps have a wide areaapplications, they are mainly used in the organization of street lighting. This is due to insufficient transmission of the color spectrum. In this case, 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 emitted in different directions.
For the correct connection of the lamps, as we now know, we cannot do without the help of third-party "equipment". We are talking about a ballast or, in other words, a choke for HPS, as well as a pulse starting device (IZU). Without this, the sodium lamp will simply refuse to start. They have already been mentioned, now it's time to get to know them better.
Control gear
In fact, this is a bundle of two main devices - a ballast (choke) and an IZU. Without a doubt, electronic ballasts are the best of their kind, in contrast to inductive devices. However, they lose to them in terms of cost - they are quite high. For this reason, ballast inductive chokes are much more widespread. In some lamps, they are already included in the device. That is, it remains to apply voltage to the terminals.
Currently, two-winding chokes are outdated and in this regard, it is worth paying attention to single-winding types. In this case, the ballast must be designed specifically for HPS light sources and have the same power as the light sources themselves.
In this case, in the connection diagram of the HPS lamp throughthe throttle must have the original (that is, "native") ballast. Otherwise, no one can guarantee full operation, including their service life. Otherwise, the light output of the lamps may be significantly reduced.
Also, other situations cannot be ruled out. For example, the effect of "flashing" - when the lamp can go out immediately after heating, and after it cools down, the whole process repeats again.
Pulse ignition "apparatus"
This is the same device that starts the sodium lamp. Different manufacturers produce IZUs with both two and three leads. Because of this, the schemes for connecting gas-discharge lamps also differ. As a rule, it is already depicted on the IZU cases. From domestic devices, it is worth taking a closer look at UIZ - it is suitable for lamps of different power and can be combined with all types of ballasts.
PRA for HPS (UIZU) can be placed in the immediate vicinity of the ballast and near the lamp itself, by connecting to its contacts. In this case, polarity does not play a special role. However, the red hot wire is recommended to be connected to the ballast.
Inclusion of a capacitor in the circuit
Hydrodischarge arc sodium lamps are consumers of reactive power. For this reason, sometimes (in the absence of phase compensation) it makes sense to include an interference suppression capacitor in the HPS 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 operating with a rated voltage of 250 V.
As for the connection of the capacitor in the connection diagram of HPS 400 with IZU, it should be done with a thick stranded wire with a large cross section. The cable itself must also withstand a load of rather weak current. A good solder or terminal block should be used, and the screws should be tightened with moderate force so as not to damage the latter.
Connection diagram
As we now know, the connection scheme for sodium lamps mainly depends on the number of IZU pins (2 or 3). The inductor, as can be judged from the diagram (it can be found in the body of the article), is connected to the supply network in series, while the IZU is connected in parallel.
In other words, the phase first enters the electromagnetic ballast, then goes to the IZU and only then to the lamp. The igniter itself can also have a zero in the case of three leads.
It is worth recalling once again that the ballast power must fully correspond to the same indicator of the lamp. This is especially true for the use of electronic ballasts for lamps. There may also be a capacitor in the circuit 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 industrial applications. If the work is done independently, it is necessary to take into account an important point - the lengthwires that connect the ballast to the lamp should not exceed 1-1.5 m.
Precautions
If you connect HPS type lamps yourself, you need to make sure that it is observed exactly. There is a drawing on the ballast body or IZU, but in its absence it is worth consulting with a specialist or a seller. The consequences of an incorrect connection are simply catastrophic:
- failure of one of the circuit elements;
- knocking out traffic jams;
- lamp explosion;
- fire.
Due to grease or other impurities, 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 socket, wipe it with alcohol. This will remove the dirt.
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 you need to wash the dust off it.
Thinking about the implementation of the HPS connection scheme, it is worth considering that it is recommended to change sodium lamps after 4 months or six months. With their further use, the light output drops noticeably.
