Frequently asked questions (FAQ) Here you will find answers to the frequently asked questions.

BAG electronics ECG feature automatic recognition and safety switch-off in case of abnormal lamp operation. This includes e.g. efectivelamp electrodes or highly resistive discharging distances caused by leaky tubes.As well, the critical operating condition at the end of service life of fluorescent lamps is detected. The at that time arising rectifier effectleads to increased lamp burning voltage in the surroundings of the electrodes and thus to raised temperature in that area. This process results from the loss of emitter material arising in the course of operating time. Particular importance inheres in this so called End-of-Life phenomenon when T5 lamps are considered. Due to the decreased tube diameter being 16 mm, the raise in temperatureis more significant than in case of T8 lamps with a diameter of 26 mm.As a consequence of the possible endangerments caused by thermal overload, the safety regulation EN 61347-2-3 for electronic control gear units includes the examination of a functional End-of-Life switch-off. There are three test methods available which of especially for T5 lamps the procedure “Test 2” is known to be particularly reliable.ECG from BAG electronics, marked are tested and approved according to the criteriarequired there.

In respect of the service life of fluorescent lamps, the number of switch-on/switch-off cycles per day and the mode of the starting procedure are of significant importance. An optimised start requires appropriate preheating of the lamp electrodes. Electronic control gear units of premium quality, feature warm start procedures which lead substantially to an increase of lamp service life of up to 50 % in comparison to an operation with inductive ballasts. A lamp service life virtually independent of the switching frequency can be achieved by means of a preheating which is exactly adjusted to the lamp. BAG electronics ECGs, e.g. of the series D and SCS, meet this requirement via digitally controlled starting procedures. Preheating is provided by an approximately constant current within a predefined period. An incidental ignition of the lamp, ahead of time, is excluded by the circuit design. Measurements in our laboratories have shown that more than 1,000,000 switching cycles at 15 seconds intervals were not able to destroy the electrodes. A technologic innovation for further optimisation of the lamp start is given by energy controlled preheating. Corresponding requirements are already constituted in regulation EN 60929 regarding performance of electronic control gear units, in fact in a first step for T5 fluorescent lamps. The advantage of this procedure is that during the starting phase not only the preheating current but the energy being fed to the electrode is considered. This allows a straight statement with regard to the point in time where the optimum emission temperature has been reached. The preheating phase is then automatically terminated. As a result, the influence of tolerances, such as of the lamp electrodes, is being reduced and thus even sensible electrodes are prevented from unnecessary loads. All marked electronic control gear units from BAG electronics for T5 lamps are already offering the optimised procedure of energy controlled preheating.

Service life and thus the reliability of electronic control gear units is determined by the failure rate of their fitted components. Along with the electrical specification and the quality of these components, the temperature is an essential parameter. BAG electronics ECGs are designed so that a failure rate of maximum 2 ‰ per 1,000 hours may be expected if the maximum admissible housing temperature tc,max which is indicated on the ECG is respected. This represents a service life of 50,000 hours at a possible failure rate of < 10 %. In other terms this means that at an annual rate of 2,500 operating hours a service life of 20 years will be achieved at a possible statistical failure rate of 10 %. Lower temperatures within the electronic control gear units extend their service life. If for instance the temperature tc, max is 10 °C lower, the failure rate is approximately halved. Analogically, in case the temperature tc, max. is exceeded this may lead to a drastic reduction in the service life. As a measure to secure the specified service life all components and circuits of ECGs from BAG electronics are designed to be operated below their admissible limiting values. Moreover, in order to prevent early failures caused by covert defects, all units pass various testing points during the manufacturing process, i.e. amongst other things component checks as well as measurements of operation-relevant data are made. Before they are delivered ECGs are subject to a final burn-in-test.

The ignition and the current limitation of the gas discharge in a fluorescent lamp require a control unit connected in series. Conventional technique use an iron core wound with copper wire in combination with a separate starter. Essential advantages are offered when using electronic control gear units: • Cost and energy savings • Increased lighting comfort thanks to flickerfree lamp start and calm light • Increased lamp service life and extended maintenance intervals • Safety switch-off in case of critical operating conditions A basic distinctive feature between inductive ballasts and electronic control gear units (ECG) is given by the mode of lamp operation. Electronic control gear units generate high-frequency alternating voltages with frequencies of about 30 to 70 kHz. As a result, the luminous efficacy of fluorescent lamps is increased by approx. 10 % versus the 50/60 Hz operation of inductive ballasts. Thus, the high-frequency operation allows to lower the system rating without reducing the luminous flux of the lamp. The physical reason can be seen from the course of the lamp voltage. When operated at mains frequency, the lamp is shortly extinguished after each mains half-wave and has to be re-ignited what results in the shown voltage peaks. The dark phases lead on an average to reduced luminous flux and the so-called 100 Hz flickering.

The Energy-Efficiency-Index serves as a basis for an objective evaluation of the efficiency of a ballast-lamp-system. This parameter has been introduced by CELMA, the Federation of National Manufacturers Associations for Luminaires and Electrotechnical Components for Luminaires in the European Union. Per lamp type 7 categories with different limiting values for the total input power are defined. In order to assure a standardised classification of a given control unit into the Energy-Efficiency-Index, measurements are based on the European Norm EN 50 294 “Measurement method of total input power of ballast-lamp circuits”. The Energy-Efficiency-Index especially applies via the implementation of the European Regulation 2000/55/EC about energy efficiency requirements as to ballasts for fluorescent lamps. This regulation aims at provoking the changeover to efficient and energy saving systems in view to improved climate protection. Against this background, according to EC-Regulation, inductive ballasts with very high power loss, classified D, are since 21.05.02 no longer allowed to be circulated. This applies from 21.11.2005 on as well for inductive ballasts classified C. Further information concerning this classification with limiting values for all common lamp types can be found in CELMA brochure called ”Guide for the application of Directive 2000/55/EC on energy efficiency requirements for ballasts for fluorescent lighting”.

In order to compare the power consumption and the efficiency of fluorescent lamp circuits, the system consisting of lamp + ballast has to be regarded in consideration of the achieved luminous flux of the lamp. For example, a fluorescent lamp rated as 58 W, requires system power of up to approx. 71 W when it is operated via a conventional inductive ballast. When using electronic control gear units the system rating amounts to only 55 W. Based on similar lighting levels, a lighting installation with conventional inductive ballasts therefore requires at least 30 % more energy than an identical lighting installation fitted with ECGs. Energy savings result as well from the reduced lamp power as from the significantly lower power loss of an electronic control gear.

Ignitors It is recommended to make a test pattern for the construction of luminaires to be equipped with a hot restrike igniter. In the event of a performance test without lamp, arc-overs or strong corona discharges must never occur upon ignition. Hissing sounds can draw attention to small leaks at hidden parts. A blueish ionisation light appears in case of high-frequency high voltage. This is usual and cannot be prevented. A test in a darkened room can provide the necessary information. In the event of a performance test with lamp, a mains interruption of approx. 15 sec should be simulated upon the specific run-up time of the lamp. If it does not ignite at the first attempt, micro-fuse and gate switch, as far as installed, have to be checked.

Hot restrike igniters and luminaires belonging to safety class I must be connected to an earth wire potential in order to protect persons, the equipment, the mains circuit and to prevent interferences. As a result, capacitive HF voltages, arising from high voltage leading luminaire parts to earth, are shortcircuited.

To start the gas discharge the gas contained in the burner of the lamp must firstly be ionised in order to facilitate a flow of current. For high-pressure sodium vapour lamps (HS) and metal halide lamps (HI) the necessary high voltage is generated by an igniter. Ordinary high-pressure mercury vapour lamps (HM) ignite without the aid of an igniter as soon as they are connected to the mains voltage. Once it is ignited the ionised gas possesses an extremely high level of electrical conductivity, so for operation the current flow has to be restricted. The current is usually restricted by the impedance of an inductive ballast. This is connected in series to the lamp and has to be adapted to suit the properties of the lamp and the mains supply because in general high-pressure lamps are susceptible to current fluctuations. Deviations from the nominal value of the current can lead to a reduction in the service life of a lamp and changes in its colour rendering.

In the attached file you´ll find a payback calculation for 30 luminaires fitted with 400W high-pressure sodium vapour lamps. Download: Pay-back calculation Power reduction

The outcome of effective lighting planning should be the most homogenous possible illumination of the lit area. Power can be reduced by various methods: 1. Using double-reflector luminaires in which one lamp can be switched off during low-traffic periods. Advantage: 50 percent saving in energy; uniform lighting still guaranteed Disadvantage: High initial and maintenance costs 2. Switching off alternate luminaires Advantage: 50 percent saving in energy Disadvantage: Danger to road safety from uneven illumination 3. Converting from high-pressure mercury to high-pressure sodium lamps Advantages: Lower costs in relation to buying new luminaires; energy saving about 35 percent Disadvantage: Luminaires are usually too small to take the additional components 4. Using power switches to reduce luminous flux Advantage: Approx. 50 percent energy saving; road safety still guaranteed because uniform lighting is maintained Disadvantage: Higher once-off initial costs, but very short pay-back periods

Directly after the switch-off of a high-pressure discharge lamp the re-ignition voltage is much higher than the ignition voltage of a cold lamp. Therefore this voltage cannot be provided by a standard igniter. Due to the high gas pressure in the discharge tube, the lamps need initially some time to cool down in order for the ignition voltage of 1 to 5 kV of the standard igniter to be sufficient. Typical times for cooling down range, depending on the wattage, between 2 and 5 minutes for high-pressure sodium vapour lamps and 10 and 20 minutes for metal halide lamps. Many lighting applications require lamps which are immediately ready for operation upon an interruption of the mains supply. This presents an absolute precondition e.g. in filming for movies and television, stadium lighting, at airports, in manufacturing plants and in fields of military or civil security. In order to comply with the requirement of an instan-taneous re-ignition of lamps in hot condition, special hot restrike igniters are used. These igniters generate significantly higher ignition voltages and thus guarantee an instant restart. A second solution for bridging the ignition time of standard igniters is BAG electronics Licht switches. These devices switch on additional luminaires during ignition time to provide a certain light level.