DRL lamps: technical characteristics and connection

The production of lighting devices has been developing very actively recently. More and more new lamps and devices are appearing to improve the quality of lighting in buildings and factories. Almost everyone has already abandoned the regular old incandescent lamp. Today, energy-saving, phosphor and halogen options are popular. One of these options is the DRL 400 lamp. This material will discuss what kind of lighting device it is, what its characteristics are and its operating principle.

What is a DRL lamp

The abbreviation DRL stands for “mercury arc lamp”. Sometimes the abbreviation RL is found. In some documents, the letter “L” means “luminophor”, since it is the main light source in the device. The element belongs to the category of high pressure gas discharge lamps.

The marking of a specific model contains a number indicating the power of the equipment.

DRL power 400 W

Economic justification for replacing the lamp

Let's calculate the operating costs:

Let's compare DRL 400 and a 100W E40 LED lamp. With daily use for 12 hours, the LED will last about eleven years. For 50,000 hours of operation, energy consumption will be 5000 kW/h.

Electricity costs – 5000 kW/h x 0.3 c.u. = 1500 c.u.

For a similar period of operation of a mercury source, 5-6 light bulb replacements will be required. Energy consumption will accordingly be 20,000 kW.

Electricity costs – 20,000 kW/h x 0.3 c.u. = 6,000 c.u.

The real numbers will be even higher, since the mercury light source is launched through a ballast, which itself is an energy consumer, electricity costs will be 10-15% higher.

Just replacing one mercury bulb with an LED bulb before the end of its life will save more than four thousand dollars.

At industrial facilities there can be dozens, and sometimes hundreds, of such lamps.

Despite the significantly higher cost of LED sources, they have extremely low energy consumption, which pays off the initial costs literally within the first half of the year of operation.

Finally, check out this monster of a light that consumes just over 0.5 kW.

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Advantages and disadvantages

DRL sources have long been used for street and indoor lighting. During this time, users managed to highlight the advantages and disadvantages that determine their choice:

Advantages:

• good light output;
• high power;
• relatively small body size;
• low price compared to LED;
• economical energy consumption;
• most products are capable of operating for 12,000 hours (the figure depends on the quality of the components used).

There are also disadvantages that are important to consider:

• inside the flasks there are harmful mercury vapors that can cause poisoning if leaked;
• It takes some time from switching on to reaching the rated power;
• a preheated lamp cannot be turned on until it cools down (about 15 minutes);
• sensitive to voltage surges (a 15% deviation will cause a 30% change in brightness);
• equipment does not work well at low temperatures;
• during operation there is a pulsation of light;
• low color rendering;
• the elements become very hot;
• in the circuit you need to use specialized heat-resistant components (wires, cartridges, etc.);
• the arc element requires ballasts;
• sometimes the switched-on element makes an unpleasant sound;
• in the room where the lamps operate, ventilation is required to ventilate ozone;
• Over time, the phosphor loses its properties, which leads to a weakening of the luminous flux and a change in the spectrum.

Most of the disadvantages are inherent only in cheap DRLs from dubious manufacturers and are insignificant when a powerful lighting source is needed.

Conclusion

When choosing a lighting device to illuminate an object, one must take into account the fact that DRL and HPS can exhibit an “aging effect” when the luminous flux dims over time. Experts determine the beginning of this period after 400 hours of operation of this type of lamp; they begin to shine at 80% of the declared luminous flux power, and then the glow decreases to 50%.

Today, LED lamps, despite their cost, are increasingly used in lighting large spaces. Taking into account the payback time and duration of operation, they make it possible to save on electrical energy.

Lamp design

Initially, the designs used burners with two electrodes, requiring the installation of an additional module for generating pulses when turned on. The voltage they created was much higher than the operating voltage of the lamp.

Design of the DRL element

Later, two-electrode elements were replaced by units with four electrodes. It is now possible to dispense with external equipment that generates ignition pulses.

The DRL lamp consists of the following components:

• main electrode;
• ignition electrode;
• electrode leads from the burner;
• a resistor that provides the required circuit resistance;
• inert gas;
• mercury vapor.

The main flask is made of durable glass that is resistant to high temperatures. The air is pumped out and replaced with inert gas. The main function of the inert gas is to prevent heat exchange between the heating pad and the flask. But even in this case, the equipment housing can heat up to 120 degrees Celsius during operation.

A base is provided to connect the lamp to the network. It allows you to secure the equipment in the chuck and ensures the tightest possible contact.

The inside of the flask is coated with a phosphor, which converts invisible ultraviolet radiation into a visible glow. Under the influence of UV rays, the phosphor heats up and begins to emit light. The shade of light depends on the composition of the coating.

The main luminous element inside the bulb is the electric arc between the electrodes.

Mercury in the light source

Mercury acts as a stabilizer for electron movement and in a cold device can take the form of small balls. When heated slightly, mercury turns into vapor and interacts with the internal elements of the structure.

The burner itself looks like a small tube made of glass or ceramic. Basic requirements for the material: preservation of properties at high temperatures and the ability to transmit ultraviolet rays.

Resistors in the circuit limit the current and prevent other elements from failing prematurely.

Principle of operation

Operating principle of DRL

The principle of operation of the DRL provides for the presence of a light source, a capacitor, an inductor and a fuse.

When voltage is applied to the electrodes, gas ionization occurs in the free region. A breakdown and arc discharge occurs between the electrodes. The discharge glow may be bluish or purple.

The phosphor is selected in a red shade. By mixing the spectra, the output is pure white light. The shade may change when the voltage applied to the contacts changes.

Thematic video: Design, principle of operation and operating features of DRL lamps.

Reaching the desired brightness in DRL takes approximately 8 minutes. This is due to the gradual melting and evaporation of mercury balls. It is mercury vapor that ensures the stability of processes inside the burner and improves the glow of the device. Maximum brightness appears at the moment of complete evaporation of mercury.

It is worth noting that the ambient temperature and the initial state of the lamp affect the speed at which the rated power is reached.

The choke in the circuit is a primitive ballast mechanism. With its help, the system controls the strength of the current passing through the electrodes of the structure. If you try to bypass the choke by connecting the lamp directly to the network, it will very quickly fail.

Nowadays, most electronic equipment manufacturers are moving away from the inductor as an outdated solution. Arc stabilization is carried out by electronic devices that provide the required performance even with significant voltage drops in the network.

Connection

In the connection diagram of a DRL lamp, it is necessary to use such elements as an inductor, a capacitor and a fuse.

Drl lamp connection diagram.

The presence of a choke ensures uninterrupted operation of the lamp. A choke is an inductor with a certain number of turns. During ignition of the DRL, if a breakdown occurs in the gas-filled flask, the resistance of the gas-mercury mixture drops sharply, provoking a sharp rise in voltage and, accordingly, an abrupt increase in temperature.

Without this simple device, the supplied current could reach critical values, and the lamp would simply burn out. The role of the capacitor is to dampen reactive power fluctuations, thereby making the DRL lamp economical.

Specifications

The main technical characteristic of sources of this type is power. It is indicated in the device labeling next to the abbreviation DRL. The remaining parameters should be considered separately. They are indicated on the box or in the equipment passport.

Technical characteristics are always indicated on the device packaging

These include:

• DRL luminous flux. Determines the efficiency of the device when lighting a specific area.
• Resource. Equipment service life if basic recommendations are followed.
• Base. Designation of the method of integrating the model into lighting equipment.
• Dimensions. A less important characteristic that determines the use of the model in specific lamps.

DRL 250

Technical characteristics of DRL 250 lamps

DRL 400

Technical characteristics of DRL 400 lamps

Scope of application

Street use of DRL

All DRL sources are used to illuminate large areas. Most often they are built into street lamps, road and gas station lighting systems. They often organize lighting for large warehouses and other premises where the color rendering parameter is not fundamental, as well as in exhibition complexes. The high power of the devices comes in handy.

They are not used in residential buildings and apartments, because... poor color rendering and long turn-on times make this solution ineffective.

Life time

The service life of DRL lamps directly depends on the power. The most common DRL 250 can operate for about 12,000 hours without any problems. It is important to remember that the following factors can reduce the resource:

• frequent switching on and off;
• voltage fluctuations;
• continuous use at low ambient temperatures.

All this leads to accelerated degradation of the electrodes and, as a consequence, rapid failure.

Disposal

The presence of mercury in DRLs places them in the first hazard class. In a number of countries, such devices are prohibited for use. However, compliance with the rules of operation and disposal minimizes all risks to humans and the environment.

DRL disposal area

It is prohibited to throw away such lighting sources with regular garbage. Mercury released into the environment can significantly harm the environment.

Disposal of DRLs is carried out by the same structures that work with other energy-saving lamps. The company must have a state license authorizing such work.

In large cities you can find special tanks in which spent elements are placed. You can also contact utility companies, lighting equipment manufacturers or repair companies, or hazardous waste disposal companies.

Comparison of DRL, DNAT and LED lamps

Table 1. Parameters of typical lamps and luminaires DRL and DNAT

* Luminous flux taking into account losses in the lamp reflector and primary degradation of lamps (depending on their type) during initial operation. Table 2. Comparative characteristics of luminaires with DRL, DNAT and LED lamps

* The average operating time of street lighting is 3800 hours per year (Mossvet, Lensvet) MYTHS that cause errors when choosing an LED analogue for DRL and DNAT lamps MYTH No. 1.
Manufacturers of LED lamps overestimate the characteristics when selecting analogues for DRL and DNAT. Perhaps there are also unscrupulous manufacturers and suppliers who overestimate the parameters of their lamps, but this should not be confused with when you are faced with a
discrepancy between the luminous flux of DRL and HPS lamps and the proposed LED analogue
!
If we really select “analogue”
, then they cannot coincide by the definition of this word.
It is necessary to take into account not only the declared initial values ​​of this parameter (luminous flux), but also to understand what it will be real
, taking into account the installation of lamps in the lamp and the start of operation.
Usually these values ​​diverge by up to 30...60% and this is all justified! Read the rationale below: MYTH No. 2. The luminous flux of DRL and DNAT lamps is approximately equal to the reference data for DRL and DNAT
.
As a rule, luminous flux reference tables are given NOT for
DRL and DNAT
, but for
DRL and DNAT lamps.
Only part of the luminous flux of the lamp shines directly from the lamp; the rest of the luminous flux must be reflected from the light diffuser. The reflector-diffuser
of the lamp
has large losses
associated with the inability to collect and form the entire luminous flux due to optical-geometric difficulties in the manufacture of the reflector, as well as large losses of the reflective material, for which the key parameters are reliability and price, rather than optical properties.
Thus, losses due to the reflector are about 20-25%
.
If the lamps have protective glass
, it also introduces losses
of up to 10%
.
Conclusion: the real difference between the luminous flux of a DRL and DNAT lamp and a passport lamp is about 27% (25..35%) MYTH No. 3. When making light calculations, you can focus on the nameplate luminous flux of the luminaire (luminous flux of DRL and DNaT lamps, taking into account the losses of the luminaire reflector). DRL and HPS lamps have severe degradation during initial operation
, which must be taken into account immediately when making light calculations!
After three months, DRL lamps lose about 30%
of the luminous flux, and after
1 year of operation, 40% of the luminous flux! After three months, HPS lamps lose about 15%
of the luminous flux, and after
1 year of operation, 20% of the luminous flux! Conclusion: to calculate illumination
for luminaires
with DRL and HPS lamps, it is necessary to take into account NOT the initial
(certificate)
luminous flux, but the luminous flux after initial operation, for example after 3 months, or better yet 1 year of operation! Note: In reality, LEDs
are not ideal either, and there are factors that also cause degradation of the luminous flux.
But for high-quality lamps with properly designed heat sinks and current stabilizers
, degradation is insignificant and can be neglected.
After three months, LEDs lose about 2%
of the luminous flux, and after
1 year of operation, 4% of the luminous flux!
MYTH No. 4.
The operation of DRL and DNAT lamps is more expensive than LED lamps in terms of the cost of lamps and the work required to replace them. The operation of DRL and HPS lamps
, of course, is mainly an expensive job of replacing burnt out and rapidly degrading lamps, where you need to take into account not only the purchase of the lamps themselves, but also mainly
the cost of expensive high-altitude work with a tower
.
You should also take into account significant additional work during operation to remove dust and dirt from the lenses and reflectors of the lamps. It is necessary to wipe the lamps quite often
, and carefully, given the fragility of the lamps.
This is quite expensive and NECESSARY maintenance
.
If you do not wipe the reflector and diffuser of the lamp in time, the loss of luminous flux can be up to 50%! Conclusion: LED lamps
also gather dust, but their design (due to flat glass and a sealed housing, as well as the absence of a reflector, which is subject to increased cleanliness requirements)
requires significantly less frequent and simpler maintenance
during operation.

Mercury arc lamps (MAV)

A currently common type of lamp used in street and industrial lighting. Developed earlier than other lamps and the least labor-intensive to manufacture, DRL lamps are widely used for indoor and outdoor lighting. DRL lamps have lower light output compared to HPS lamps

,
but unlike them, they do not require additional high-voltage starting devices for ignition.
The ergonomic indicators of lighting of DRL lamps (pulsation coefficient of the light flux, correspondence of the emission spectrum to the solar spectrum) are slightly worse than, for example, those of DRI lamps, but much better than those of HPS lamps.

Tubular sodium arc lamps (HPS)

Currently, they are widely used for lighting streets, highways, public buildings, etc. lamps have the highest luminous efficiency among gas discharge lamps

and a smaller reduction in luminous flux with long service life.
Due to the very high pulsation coefficient and the large deviation of the lamp's emission spectrum towards the red region, which disrupts the color rendering of objects
,
it is not recommended
to use HPS lamps for lighting
inside industrial and residential premises
.
The large dependence of the light output and ignition voltage of HPS lamps on the composition and pressure of the internal gas, on the current passing through the lamp and on the burner temperature places very high demands on the quality of manufacture and operating conditions of HPS lamps.
Therefore, for efficient operation of HPS lamps, it is necessary to provide “comfortable” operating conditions - high stability of the supply voltage, ambient temperature from -20C to +30C. Deviation from “comfortable” operating conditions leads to a sharp reduction in lamp life and a decrease in light output. The service life of HPS lamps is also affected by the quality of the pulse triggering devices used. Currently, there is a widespread misconception that replacing DRL lamps with more efficient HPS lamps leads to improved lighting quality and energy savings. This does not take into account that a HPS lamp of similar power with a higher luminous flux also has a higher current consumption. In addition, the predominance of the red spectrum from HPS lamps worsens the overall visibility of illuminated objects, which is especially dangerous for lighting high-speed highways. LED lamps

LEDs themselves have been used for a long time, mainly for display. The emission of light by an LED occurs through the recombination of photons in the region of the pn junction of the semiconductor during the passage of current. The breakthrough in the field of LEDs that occurred several years ago was associated primarily with the production of new semiconductor materials that increase the brightness of LEDs by more than 20 times.

Unlike other technologies, LEDs have a very
high efficiency
- at least 90% (95-98%).
Most existing technologies involve heating a body or area, which requires a decent amount of energy. Thanks to its high efficiency, LED technology ensures low power consumption
and low heat generation.
In addition, due to the very nature of receiving radiation, LEDs have a set of characteristics unattainable by other technologies. Mechanical and temperature stability, resistance to voltage surges, long service life, excellent contrast and color rendition.
Plus environmental friendliness, no flicker and even light .
This is the quality of modern technology. Analysis:
It is important to highlight one more point that is not mentioned above. DRL and HPS lamps have an aging effect. It is reliably known that after 400 hours of operation the drop in luminous flux of DRL lamps is more than 20%, and by the end of their life it is more than 50%. For most of its service life, the lamp emits only 50-60% of the rated luminous flux. This can be clearly seen from the luminous flux decay curve. The situation with DNATs is even sadder, due to their lower temperature stability. LEDs don't have this. LEDs maintain their parameters at the original level throughout their entire service life. Only towards the end of the period can a slight drop be observed. This is where an interesting and important point comes to light. It turns out that if you measure the parameters, for example, every month during the entire service life, and then calculate the average, it will be about (!) 60% of the nominal value. The declared parameter values ​​concern only the initial period of operation and will constantly fall along the curve from the very beginning. This is nothing more than the costs of existing technologies. The above can be interpreted as follows. For the declared characteristics (primarily the luminous flux), you pay more or pay 100% for characteristics that are actually ~40% lower.

Efficiency of using these types of lamps.

DRL.

The simplest and most affordable technology.
Low initial costs, provided there are no stringent lighting requirements, justify its use. DNAT.
The best light output among gas-discharge lamps is the only serious advantage over DRL.
But a very weak color rendering index and high sensitivity to temperature cast doubt on the feasibility of replacement. HPS is not recommended for indoor lighting, and is even banned in some countries. Lighting roads, especially highways, is also not recommended. When lighting any other areas, the use of HPS lamps can be considered justified compared to DRL. LED lights
.
It may seem incredible, but LED lamps have no technical disadvantages. They are better in everything. In addition to the above, we can add that LED lamps do not require inrush currents, and therefore require a smaller cable cross-section. The only negative is that they are significantly ahead in price. How justified is their use? Taking into account all factors related to the operating costs of DRL or HPS lamps, the payback period for LED analogues begins at 3 years. That is, 3 years (or more) an LED lamp pays for itself, and in all subsequent years it makes a profit. All the while producing the highest quality light compared to other technologies. Overvoltage and LEDs. Voltage cannot be applied to the LED as such due to its current-voltage characteristic (volt-ampere characteristic). Either it won't light up or it will burn out, so the LED is controlled by current. The easiest way is through a resistor. The lamp provides a so-called driver to supply “edible” current to the LED circuit. The driver not only acts as a converter (adapter), but also protects the LEDs from overvoltage and power surges. In this case, it is the driver that takes the hit, which significantly reduces the cost of non-warranty repairs of the lamp.