Technical information

Electronic ballast

Why an electronic ballast?
It has been demonstrated that people working in areas where the luminaires have electronic ballasts feel better, experience less fatigue and achieve more. Even though not everyone is consciously aware of the flicker of fluorescent tubes with ordinary reactors, the blinking effect is unconsciously registered by the brain.

And as the electronic ballast uses energy more efficiently, i.e. the installed luminaire output and output losses are lower, there is also less heat evolved. As a result, cooling and air conditioning equipment can be dimensioned for a smaller output. So you achieve savings both in purchase price and in operating costs.

Maintenance and servicing costs are reduced due to the longer service life of the light sources. When changing tubes you no longer need to replace starters, as the starting function is integrated in the electronic ballast.

Benefits of electronic ballast:
- Quick, blink-free ignition.
- Flicker-free light.
- Very low magnetic field.
- The light source works under optimum conditions and gives the correct luminous flux regardless of supply voltage variations.
Extends the service life of the light source.
- Minimal development of harmonics (THD).
- Turns off defective fluorescent lamps (no annoying blinking).
- Saves at least 20% energy. Up to 60% savings are possible through dimming, constant lighting control and/or occupancy detection. Dimming of fluorescent lamps, only possible with electronic ballasts.
- Low incidence of waste heat.
- No stroboscopic effect.

Electronic ballasts are an environmental choice
Electronic ballasts (HF) are environmentally friendly. The biggest benefit to the environment comes from the electronic ballast’s energy savings. Another important environmental factor is that the service life of the fluorescent lamp is increased by an average of 15%, thus reducing the impact of mercury vapour on the environment.

The electronic ballast raises the fluorescent lamp’s working frequency to around 40 kHz, so the tube functions completely evenly without any blinking. At the same time its efficiency is improved by approx. 10%.

An electronic ballast ignites the fluorescent lamp in a controlled fashion. The warm start avoids uneven emissions from the cathodes, and this is thought to prolong the service life of a fluorescent lamp by up to 50% in locations with normal on/off switching.

With a warm start electronic ballast, the cathodes are pre-heated before the ignition pulse is sent to the fluorescent lamp. Modern high-quality electronic ballasts also have a function which greatly reduces or completely cuts out the pre-heating current once the fluorescent lamp has ignited. An important function for saving energy, but also for ensuring that the T5 light source operates under optimum temperature conditions.

Once discharge begins and the fluorescent lamp ignites, the electronic ballast controls all necessary parameters for ensuring constant luminous flux regardless of variations in supply voltage. The electronic ballast also monitors the function of the light source and turns it off if a fault occurs. There are also electronic ballasts on the market which can use the light source to “signal” a fault in the connected mains voltage, e.g. overvoltage.

Design of luminaires for electronic ballasts requires great care with regard to wiring. Internal wires to the fluorescent lamp must be routed so as not to impair functionality. Too long an internal wire to the fluorescent lamp can also cause interference problems (EMC).

Great care must also be taken with incoming mains conductors. Due to EMC requirements, mains conductors must not be laid together with internal conductors. Therefore the luminaire usually has a separate channel or clip row to take these conductors.

So-called master-slave devices in which two connected luminaire units are served by an electronic ballast located in one of the units can only be recommended for a standard ballast and where internal conductors can be kept shorter than 1 m. Master-slave solutions for dimming ballasts are not recommended due to the high risk of function failure (different light levels in the luminaire units).

Service life
Electronic ballasts, as with all other electronics, have a limited service life. This is determined by choice of components, mains interference, number of ignitions and above all by the ambient temperature in the luminaire. The fault frequency of the electronic components of the electronic ballast may cause early failure during the first hours of operation. Subsequently, the fault frequency in electronic ballasts is comparable to other electronics.

Service life and function can be jeopardised by faulty handling during installation.
The electronic ballast can be damaged by e.g.
- Incorrectly executed measurement of insulation resistance
- Current spikes caused by machinery at the workplace
- Excessive temperatures if the luminaire is used in a space with elevated temperatures (normally >25 °C). The ta (maximum permitted ambient temperature) of the luminaires is in most cases 25 °C, but luminaires with higher ta do occur. The service life of the electronic ballast, as previously mentioned, partly depends on the ambient temperature. Normally there is a temperature control point (tc point) on the electronic ballast which must be checked when the device is integrated in a relevant product. Tc max varies from make to make and type to type, and indicates the highest permitted temperature before the device suffers damage.


Warm start
An optimised ignition of the fluorescent lamp whereby the cathodes in the tube ends are pre-heated to the correct temperature so that discharge can occur in a controlled fashion. This provides the best conditions for maximum service life in the fluorescent lamp.

Cold start
The fluorescent lamp is ignited without pre-heating of the cathodes. This will cause the emission element of the cathodes to wear out sooner. The advantage of this starting method is a smaller and cheaper electronic ballast assembly. These are only suitable for industrial locations and other areas where the fluorescent lamps are not switched on and off more than max. once or twice a day.

Nominal voltage
The rating plate on the luminaire showing the operating voltage. It can normally be assumed that the electronic ballast will have no difficulty operating within a ±10 % variation of the nominal voltage. Check the voltage is correct, as too high or too low a voltage may damage the electronics. Most electronic ballasts also work with direct current voltage.

Harmonic overtones
Harmonics are a distortion of the voltage wave form caused by non-linear loads on the grid. Harmonics cause stray currents, high magnetic fields and interference in sensitive electronic devices. Computers, frequency transformers and ordinary compensated luminaires are significant harmonics generators. The guideline for computers is approx. 80 % THD, for ordinary luminaires approx. 20 % THD and for electronic ballasts round about 10%. Low quality electronic ballasts can also generate high quantities of harmonics.

Total amount of harmonics. Stands for Total Harmonic Distortion.

Operating frequency
Frequency of discharge current in fluorescent lamp (the light-generating current in the tube). In luminaires with magnetic ballasts, this is equal to the mains frequency 50 Hz. An electronic ballast converts the mains frequency to approx. 25-50 kHz. At the same time the fluorescent lamp’s efficiency is improved by approx. 10%. As the operating frequency also modulates the light, this can sometimes cause problems with infrared detectors used in alarm systems and for lighting control. However, problems can be avoided by correct choice of electronic ballast.

Also called electrode. The cathodes at either end of a fluorescent lamp consist of tungsten incandescent filaments coated with beryllium oxide. When heated up, the cathodes release electrons which maintain the fluorescent lamp's discharge current. The wrong temperature in the cathodes will shorten the service life of the fluorescent lamp. 

Particularly in the case of dimming, as the output of the fluorescent lamp will fall and cold emissions can seriously shorten the service life of the fluorescent lamp. Such problems can be avoided by the use of high-quality electronic ballasts. Electronic ballasts with high tc-max are not automatically better than those with low tc-max. The maker of the electronic ballast may have chosen to locate the reference point at a cool or hot position on the electronic ballast.

The service life of an electronic ballast is indicated by a particular temperature at the tc point. Sometimes this is the same as the tc-max, but it can also be a lower temperature. Normally the makers specify 50,000 hours service life with a maximum failure of 0.2%/1000 hours, corresponding to a 10% failure rate.

The cooler the tc temperature the longer the service life. A rule of thumb is that a temperature 10° lower at the tc point will give double the service life, while a 10% higher temperature will halve it.

Fuse protection of electronic ballast

Miniature circuit breakers
Miniature circuit breakers for groups of luminaires with electronic ballasts must be dimensioned not only according to the rated current but especially in respect of the inrush current. The brief inrush current which occurs when the luminaires are ignited can cause an miniature circuit breaker to cut out if incorrectly dimensioned. The inrush current is caused by the capacitors in the electronic ballast’s mains filter. The level of the inrush current does not depend on the output of the electronic ballast but on its design. There are relatively large variations in the size of the inrush current between the various suppliers of electronic ballasts. Due to the inrush current characteristics we recommend the use of miniature circuit breakers with time-current characteristic C.

As manufacturers are continually developing their products, the information on this page must not be taken as binding. For the most recent information, check with the manufacturers of the electronic ballast. We reserve the right to make changes and disclaim liability for any errors.

System outputs
System outputs are the total of a light source's output and losses from the associated ballast. An installation must be dimensioned with regard to both the connected output and the inrush current. Normally it is the inrush current and not the system outputs which decide how many electronic ballasts can be connected to an miniature circuit breaker (MCB). The following presents the system outputs for a number of different light sources in combination with an electronic ballast or electronic ballast assembly.

NB: Small differences will occur in other ballasts not mentioned here. Indicated values are examples and rounded to the nearest whole number. Development of ballast assemblies is on-going, so the indicated values may need to be adjusted. The output factor, cos phi, for luminaires with electronic ballast or electronic ballast assembly lies between 0.95 and 1.0.


For controlling lighting systems
Modern lighting control systems are able to improve both lighting quality and comfort. With a modern luminaire with lighting control you can direct the light to the desired place at the right time and in the right quantity. In combination with a light sensor, incident daylight can also be used, thus saving energy. In many rooms, lighting requirements change several times a day. Hence the ability to control the light is an important factor, e.g. in conference rooms and restaurants. An installation with pre-programmed lighting levels, lighting scenes and remote control will allow efficient use of such rooms’ lighting systems.

Lighting scenes
Lighting control systems also allow you to store pre-selected lighting scenes. These scenes can be divided either at channel level or in combination with a master system which controls all channels in the system.

Suitable lighting scenes are chosen via wall panels or remote controls, and the system automatically sets up the pre-selected lighting level for each lighting group.

Computer control 
Digital ballasts can be controlled from a computer via an interface. Appropriate software enables you to control the lighting system in the same way as from wall panels. The DALI system requires programming and larger systems are best programmed using a computer. The leading makers have developed software which can be downloaded free of charge from their websites on the internet.

Occupancy sensors 
Occupancy sensors use heat radiation from the body to detect movement within their detection area. The monitored area is illuminated only when people are present. This requires a higher sensitivity in indoor lighting occupancy sensors than for similar outdoor lighting devices as the sensors need to be able to pick up even very small movements from seated persons. Also available in combination with other functions such as lighting level control and IR receivers.

Remote control 
Remote control can be used for simple selection of a desired lighting scene or lighting level. Individual control of channels is also possible. And of course, all lights can be switched on and off by remote control. Remote control works by radio signals or commonly by infrared light. There are also systems available on the market which just turn the lighting on and off.

The DALI system can be remotely programmed, but for larger systems it is preferable to perform programming with a PC and appropriate software. Division into channels. With today’s modern lighting control systems, several luminaire groups or channels can be controlled centrally from one or more locations. A traditional control unit, such as a dimmer integrated in an appliance socket, adjusts all luminaires connected to the same channel. This is called single channel control. More advanced systems may include several tens of different channels, which can be controlled individually or together.

Technical limitations
Many lighting control systems require separate central or master units.

However, in the DALI system the logic is distributed between the system components, so no separate central unit is required. Luminaires require a special control circuit, a double pole control wire, which may necessitate additions to older lighting installations. Older lighting adjustment systems can usually be supplemented with new luminaires, for example by using an interface which is able to convert analogue signals to digital.


Stepless adjustment of luminance.

Lighting control system
System which controls individual luminaire groups and/or whole systems.

Electronic ballast (HF) for dimming
Ballast which permits dimming via a separate control circuit.

Digital lighting control system
Control signals between the units are transmitted in the form of digital commands. Commands in digital form are less sensitive to interference than analogue systems.

Analogue control system
An analogue system is commonly based on 1-10 V DC between the control unit and the luminaire. These systems control either the voltage or the resistance of the control circuit. The length of the control wires may affect the control result.

Phase control
A system based on control of the lighting level via 230V (e.g. by using a momentary wall switch or an integral pull switch in the luminaire). Best known under the name SwitchDim. The system requires a 4-conductor connection to the luminaire if a wall switch is to be used.

Addressed control
The units in the system can be individually addressed enabling them to be controlled independently of each other. This system requires the DALI digital protocol.

Multi-channel control
An installation can be divided into several groups or channels which can be controlled independently of each other or together.

Lighting scenes
A setting for a lighting situation/arrangement which can be simply retrieved on demand.

Constant lighting level
The system strives to maintain the luminance within a desired area (e.g. under the luminaire) at a constant level. The level of the artificial lighting will be affected by incident daylight. Used to save energy.

Occupancy sensor
A sensor which detects a person's heat radiation. Any movement within the sensor’s detection area will turn on the luminaire. An integral timer turns off the luminaire if no movement occurs within the sensor’s detection area.

IR receiver
Receives signals from the remote control and passes them on to the system. Usually integrated in a wall panel or multisensor.

A sensor which usually comprises the functions of constant lighting level, occupancy detector and IR receiver.

Different types of dimming systems

Incandescent lamps and low-voltage halogen
The simplest system for dimming incandescent lamps is by the use of a thyristor, so-called phase control. The thyristor cuts the leading edge of the sine wave. Control of low-voltage light sources such as halogen requires a controller that is compatible with the transformer being used.

Conventional transformers with iron cores are controlled with thyristors, while electronic transformers generally require a transistor controller. Unlike thyristors, these regulators cut the trailing edge of the sine wave. There are also electronic transformers on the market suitable for either type of controller.

Fluorescent lamps
Dimming of fluorescent lamps requires the power to pass through a suitable ballast designed for dimming. It is not possible to dim a light source where power is supplied from a conventional ballast.

In general there are four different control principles for dimming fluorescent lamps. Control principle means the type of signal transfer between the controller and the electronic ballast assembly in the luminaire.

The most common control principles are:
- DALI, (Digital Addressable Lighting Interface) - DSI
- Phase control, best known as SwitchDim. Not to be confused with traditional thyristor control.
- Analogue system (1-10 V DC).

The choice of principle will determine not only the components used in the system, but also how far downwards the lighting can be adjusted, how installation is to be executed, the cost of the system, etc. Digital systems are generally dearer than analogue but have technical and convenience benefits which may well justify the extra cost. In certain applications, it is convenient to combine digital systems with simpler analogue systems.


- Components from several different manufacturers can be combined in the same system.
- Each unit in the system is addressed.
- Easy to modify and expand.
- Only one pair of control wires, even in multi-channel systems, giving lower installation costs.
- Non-polarised control wire reduces risk of faulty connections.
- Can be controlled from computer using an interface.
- Can be connected to BMS system (LonWorks, EIB) via gateway.

- The system needs to be programmed before use.
- Programming varies between products from different manufacturers.
- Max. 64 addresses per system (Note that the interface for programming via a computer requires an address).
– Larger systems can be constructed by use of software/server/gateways. Such systems generally use existing data networks (TCP/IP). An example of such a system is WinDIM@net from Tridonic.

- Digital data transfer means that all luminaires are controlled in the same way.
- Non-polarised control wires reduce the risk of faulty connections.
- Can be controlled via a computer.

- The components in the system are not addressable.
- In multi-channel systems, each channel will require separate control wires.
- There is only one manufacturer of the system.

Phase control, e.g. SwitchDim

- The system does not require advanced control units.
- Standard switches of momentary type can be used.
- Only one extra phase conductor is necessary for the control circuit.

- Wall switches must not be fitted with pilot lamps.
- Max 25 electronic ballasts/ per system are recommended.
- Avoid combining different makes in the system.

1-10 V
- Well-known and easily understood system.
- Control units are available from most manufacturers.

- Certain analogue 1-10 V control systems on the market are unsuitable for controlling ballasts for 1-10 V DC according to EN60929.
- The length of the control wires may affect the control result.
- The 1-10 V system can only be controlled from one location (a control unit).


DALI - addressed digital control system
DALI (Digital Addressable Lighting Interface) is a standardised digital protocol for dimming. Behind DALI are Europe’s leading manufacturers of electronic ballasts (Helvar, Osram, Philips and Tridonic). Other enterprises within the lighting industry have also joined the group of DALI manufacturers.

DALI uses a simple wiring system allowing a two-way digital signal to be transmitted between all units in the system. The interconnected electronic ballasts, control panels, sensors and programming units communicate with each other. The system’s “intelligence” is distributed (i.e. stored) in the various parts of the system. This gives higher safety and reliability as the system does not depend on a single central unit.
The DALI system is also very flexible and future proof, as a change in the layout or use of the room requires only reprogramming of the system settings. Generally speaking, the wiring does not need to be changed.

In the DALI system, information is transferred between components via an addressed digital system. Because the signal is digital, all connected luminaires included are controlled in exactly the same way, regardless of the distance between the control unit and the luminaire. The DALI electronic ballast is designed for higher sensitivity to changes in lighting levels, so-called logarithmic compensation. Apart from the phase, neutral and earth conductors, two conductors for the digital signal are connected to the luminaire. These conductors are non-polarised, which simplifies the installation.

The digital control signal is also insensitive to external interference. The lighting is turned on and off by a digital command via the DALI conductors. Hence mains voltage can conveniently be connected directly from the group switchboard to the luminaire.

Combining DALI with other control systems
DALI can be conveniently combined with other control systems such as analogue 1-10 V. If there is a need to control or monitor a single luminaire or the aim is to control a row of luminaires in the same way, an interface (converter) between DALI and the 1-10V may be a suitable solution. In this case the luminaires are fitted with electronic ballasts for analogue 1-10 V dimming and connected to a DALI to 1-10 V interface.
With this solution the luminaires can be controlled centrally, e.g. via DALI panels. The solution will be more economical and will also permit the number of luminaires in a DALI system to be considerably higher. This is because each DALI address will control several luminaire units. The same solution can also be implemented with luminaires equipped with electronic ballasts for DSI control, but by using a DALI to DSI interface.

- Following installation, the system must be programmed. Programming is carried out at wall panels, via remote control or with the use of computer software. For larger systems we recommend the use of software.
- DALI requires a powered control circuit. This current must be max. 250mA, obtained by connection to an external DALI power supply. Too high a current in the circuit will cause communication to break down or may damage components. It is thus important that a DALI system is planned and dimensioned correctly.
- Maximum cable length for the control circuit is 300 m.
- Properties of units from different manufacturers will vary somewhat.

Non-addressable digital control system DSI

Non-addressable digital control system (DSI)
Electronic ballasts (HF) designed for DSI control are manufactured only by Tridonic. In the DSI system the control information is transmitted to the electronic ballast via a non-addressable digital signal. One advantage of digital control is that it is independent of the length and resistance of the control circuit. All luminaires connected to the system are controlled in the same way, regardless of the distance between the control unit and the luminaire. Digital control also allows for control of light sources with different outputs, as the electronic ballast is compensated for enhanced sensitivity. Apart from the phase, neutral and earth conductors, two conductors for the control circuit are connected to the luminaire. The control bus is non-polarised, which simplifies installation. Control and mains voltages connected to the same controller may be run in the same conduit or cable mantle for a length of up to 250 m, as the digital signal is very insensitive to interference. The lighting is turned on and off with a digital control command, so the mains voltage can be connected directly from the group switchboard to the luminaire. The luminaires are live even when turned off. Depending on the type of light source, the minimum level is 1 %, 3 % or 10 %.

DSI ballasts
Tridonic makes two ranges of dimmable ballasts, Excel and Eco. The Excel device provides all the properties of the Eco variant, but also has a facility for interpreting DALI commands, a memory in case of voltage failure and a facility for programming parameters and for transmission of error messages.

- The DSI control system is non-addressable.
- The luminaire/group can also be computer-controlled using the Win-DIM program. This will require the computer to be connected to the luminaires’ bus system via a WinDim cable.
- The WinDIM program is available over the Internet, (

Phase control SwitchDim, TouchDim
Phase control system - SwitchDim, TouchDim etc.
Phase control is a simple and economic variant of lighting control which requires the use of controllable electronic ballasts designed for this function. Normally these devices are also capable of control via bus systems such as DSI, DALI or 1-10 V DC, depending on make and type. However, the functions cannot be combined, as this will result in serious damage.

No controller or other control device is required for phase control. The signal to the electronic ballast is received directly from simple momentary switches. No other additional modules are required. Simply put, the controller is integrated in the electronic ballast. Only four conductors are required for the luminaire: Direct (constant) mains voltage, neutral, earth and mains voltage (pulsed) via the switch. Controlling a luminaire mounted in a traditional socket requires no changes to the wiring. Apart from mains voltage via the switch, direct mains voltage is also connected to the luminaire and the switch is replaced by a momentary version.

Phase control is also an excellent system for controlling a lighting installation from several locations in the room. The simplicity is obvious and the absence of intermediate units makes such an installation simple and cheap.

Depending on make, this control method can be combined with e.g. a daylight sensor. For example, a Tridonic device can combine phase control with the sensor SMART LS II. The preset lighting level is set with the button by shifting the control curve up or down. The sensor then strives to keep the level constant at the new level. The control curve returns to the preset value when the luminaire is turned off and on again.

As control buttons, a 230 V switch with closing contact and impulse spring or else a switch with a return spring are used. In using the switch, the luminaire is turned on and off by a brief pressure, while luminance is adjusted, up or down, by holding the button down.
Alternatively an up/down switch can be used (requires a DSI control module), where one switch increases the luminance and the other decreases it. The lighting can be turned on and off with either button.

With regard to Tridonic SwitchDim
- Unlimited number of parallel connection buttons for off/on/dimming can be installed.
- In a SwitchDim installation max. 25 PCA electronic ballasts are recommended.
- Connection of the push-button phase and neutral to the electronic ballast is non-polarised.

- The control buttons must not be fitted with pilot lamps, as the leak current from these will cause a malfunction.
- The maximum length of the control wire is normally unlimited, since the signal is a 230/240 V signal pulse.
- The same phase must be used for both control and for power supply to the luminaire. In this solution, connection is non-polarised, which means that the luminaire can also be fitted with a plug. 3-phase connection is possible but requires a special polarised connection.
- Simultaneous use of phase control and another control method such as DALI or DSI will cause serious and irreparable damage to the digital control equipment.
- Avoid combining different makes in the system.

If the PCA electronic ballast with SwitchDim is not synchronous with the other installed PCA electronic ballasts (behaves differently from the other devices/falls out of sync), installation can be synchronised by holding the push button down for > 10 seconds. All PCA electronic ballasts will then be synchronised at the 50% level, after which the installation can be used normally again. Synchronisation can be performed at any time during normal operation.

Absence dimming - new function
The new electronic ballasts from Tridonic, PCA ECO and Excel, can also be used for varying between high level (presence) and low level (absence) by use of occupancy sensors. A very useful function for stairwells, corridors and access spaces. Large quantities of energy can be saved in this way, without completely turning off the lights.

Momentary switches must be used. Without pilot lamp. A maximum of 25 electronic ballasts can be connected to one control system. The same phase must be used for control and power to the electronic ballast. If several electronic ballasts or more advanced controlled systems are desired, contact ateljé Lyktan.

1-10 V system

Analogue 1-10 V direct voltage control system (EN60929)
Most dimmable electronic ballasts are designed according to Standard EN60929 for controlling an electronic ballast with 1-10 V direct voltage. The electronic ballast itself creates the necessary control current and in the simplest case, a potentiometer (normally linear, approx. 47 k) will suffice as control device. Most manufacturers' potentiometer controllers also contain electronics.

The electronic ballast detects the voltage in the control circuit. The lower the voltage, the lower the lighting level. If the control circuit is left open, the luminaire will operate at full strength exactly as in a luminaire without control. If the circuit is jumpered, the lighting level will fall to the minimum value. The minimum level of luminous flux will vary according to make, type and light source. Normal minimum levels are 1-5 % for straight fluorescent lamps and 3-10 % for compact fluorescent lamps. Check what applies to the luminaire you are interested in.

Apart from the phase, neutral and earth conductors, two conductors for the control circuit are connected to the luminaire. The control wires may lie in the same conduit or cable as the mains voltage to the luminaire. Even though the voltage is maximum 10 V, the insulation on the control wires must fulfil the requirements for a heavy current installation. When connecting the control circuit, correct polarity must be ensured, as a faulty connection will cause the system to revert to its minimum level.

Apart from the control wires, the phase conductor must also be connected via the switch combined with the control unit or potentiometer, as the luminaires can only be turned on and off via the mains voltage. It is important to remember this when planning the wiring, as changing the installation later can be difficult.

During installation account must also be taken of the breaking capacity of the potentiometer switch. Even though the potentiometer can be used to control up to 50 electronic ballasts, the capacity of the switch will often only be enough for 5-10 luminaires, depending on their output. Larger loads will require a contactor.

- When choosing a control system, the compatibility of the system and the luminaire must be considered. Luminaires implemented in accordance with Standard EN 60929 themselves provide the power for the control circuit, something analogue control units will not allow.
- There are special requirements for joining control wires in sockets together with other heavy current wires.
- Polarity of the control circuit must be carefully observed. The control system will not function correctly if any of the light fittings in the group have the wrong polarity.

Do not mix electronic ballasts from different manufacturers or with different outputs. Control potentiometers can usually control 100mA (approx. 50 electronic ballasts), but they have different breaking capacities on the switch function. Always check the supplier’s information.

Do not mix electronic ballasts from different manufacturers or with different outputs. Control potentiometer and control unit can usually regulate 100mA (approx. 50 electronic ballasts). The same control signal can be connected to the electronic ballast regardless of supply phase, with common off function via a contactor.

The occupancy sensor will turn the lighting on and off depending on the presence of persons. The switching function of the potentiometer need not be used, and if it is bypassed, light at the pre-set level will always be provided if persons are present. Occupancy sensors of different makes can be used. Always check that the sensitivity is OK and that the relay function can handle the connected load. Adjustment of lux levels can be used in rooms with plentiful daylight. This function will prevent switching on in case of plentiful daylight.


Tridonic SmartDIM SM
Tridonic SmartDIM SM concept is a sensor system for occupancy detection and constant lighting. All control is performed by DSI signals, and this requires that the luminaires be equipped with Tridonic electronic ballast type PCA ECO or PCA Excel. A maximum of 25 electronic ballasts can be connected to one system. Can also be combined with a phase control system, e.g. SwitchDIM. This control system is connected to the control unit SmartDIM SM, which is situated in the luminaire. Other connected luminaires in the system are controlled via DSI signal (2-conductor) from the control unit.

Two different sensor designs are available:
SmartDIM Sensor 1 which is the smaller unit and designed for fitting in the luminaire and SmartDIM Sensor 2, a somewhat larger unit, and better suited to fitting in the ceiling. SmartDIM Sensor 1 also has a mirror as an accessory, the Smart DIM Mirror. This mirror increases the detection area in one direction. Suitable for use in corridors, etc. The Smart DIM Mirror can also function as a shield.

On the control unit, the following functions can be set via DIP switches:
- desired minimum lighting level (1 % or 10 %).
- options for changing the constant lighting level. (Functionality of connected push button.)
- delay time for turn-off when no occupancy is detected. A fixed period of 20 minutes (last 2 minutes with minimum light) can be selected, or a so-called adaptive setting, in which the sensor memorises and stores a suitable time interval depending on the number of movements within the detection area.

On the sensor part you can choose whether the sensor is to turn the luminaire on and off (Auto) or if automatic turn-off but manual turn-on (Man) is desired. More information can be downloaded from

SmartDIM Sensor 2, for mounting in ceiling (surface)
Tridonic SmartSWITCH
Tridonic SmartSWITCH is a simple on/off sensor which “controls” the connected luminaire via the mains voltage. The sensor can be loaded with max. 200 VA/500 W and is designed for integration in the luminaire. SmartSWITCH has a mirror as an accessory, the Smart DIM Mirror. This mirror increases the detection area in one direction. Suitable for use in corridors, etc. The Smart DIM Mirror can also function as a shield.

The following functions can be set:
- off-function delay from 5 seconds to 30 minutes.
- off-function at light levels between 50-2000lx.
This function can be disabled. More information can be downloaded from

T5 fluorescent lamp, T5 system as a whole
T5 system 
The T5 fluorescent lamp provides no more than 4% extra light in itself, but, depending on the type of luminaire, creates the conditions for increasing the optical efficiency of the luminaire by approx. 35%. This is the case with luminaires with reflector shield and where the luminaire has been optimised in respect of design and choice of reflector material, light distribution and electronic ballast.

T5 fluorescent lamp
The T5 fluorescent lamp with a smaller tube diameter has created new opportunities for a more energy efficient and environmentally friendly lighting system with significantly lower life-cycle costs.

Clear advantages of T5 fluorescent lamp
- Creates conditions for more energy-efficient luminaires.
- Flicker-free light with better light quality due to electronic ballast.
- Approx. 4 % better luminous efficacy from lamp (104 lm/W ).
- Increased luminous flux at higher ambient temperatures.
- 40 % reduction in tube diameter provides optical benefits.
- Reduced length and tube diameter give design benefits.
- Modular adaptation for 600, 900, 1200 and 1500 mm below the ceiling.
- Same luminance from outputs 14/21/28/35W
- 17 kcd/m2.
- Only approx. 3 mg mercury per fluorescent lamp.
- Lumen depreciation only approx. 8 % after 10,000 operating hours.
- Long service life, 17,000 hours.

T5 fluorescent lamps are available in three versions, all with different application versions
T5 fluorescent lamps with maximum luminous efficacy
Available in outputs of 14, 21, 28 and 35 W. Maximum luminous efficacy of up to 104 lm/W. With these fluorescent lamps you can normally plan the most energy-efficient lighting solutions.

Areas of application are in principle unlimited, but examples are offices, retail stores, schools, hospitals, hotels and industry. Fluorescent lamps are dimmable and their service life is as much as 17,000 hours due to lower lumen depreciation over time.

T5 fluorescent lamps with maximum luminous flux
Available in outputs of 24, 39, 49, 54 and 80 W. These have higher outputs and luminous flux levels and are available in the same lengths as above. On the other hand their luminous efficacy is somewhat lower. You should use these fluorescent lamps if you want lots of light with shorter luminaire lengths. For example, these lamps could be useful for indirect lighting, background lighting, in industry and in locations with high ceilings. It may also be suitable to use this type of fluorescent lamp in single-tube luminaires rather than using fluorescent lamps with maximum luminous efficacy in certain 2-tube luminaires.

Note that these fluorescent lamps have a higher luminance than tubes with maximum luminous efficacy, something which should be specially noted in luminaires with only direct light. They are dimmable and their service life is 17,000 hours.

T5 circular fluorescent lamps
The circular T5 fluorescent lamps actually only have their tube diameter in common with the two straight T5 lamps. The luminous efficacy of the circular fluorescent tube is lower, approx. 83 lm/W, and its average life is approx. 12,000 hours. These fluorescent lamps emit their maximum luminous flux at approx. 25 °C, and not at 35 °C as in the case of straight T5 lamps. Even so, the area of application for the T5 circular fluorescent lamp is wide, as the lamp’s shape makes it suitable for aesthetically pleasing luminaire designs, for instance in ceiling fittings and pendant luminaires.

Light sources, properties and summary

There follows a summary of the commonest light sources. This data has been collected from light source manufacturers’ catalogues, and may vary according to the manufacturer, so we reserve the right to make changes.

Compact fluorescent lamps
The benefits include high luminous efficacy, good colour rendering, several different colour temperatures, long service life, facility for dimming etc. Compact fluorescent lamp FSD/TC-L: Powerful compact fluorescent lamp providing small luminaires with lots of light. Compact fluorescent lamp FSD/FSQ/FSM/FSS: Efficient compact fluorescent lamp with 2, 4 or 6 pins or 2D design in outputs up to 120W. FSM lamps are available in different versions with varied geometry and properties. Amalgam lamps are recommended as they give a high luminous efficacy at high ambient temperatures. Generally small luminaires of the downlight type have high ambient temperatures. One limitation of amalgam lamps is that it takes about 5 minutes to reach their full luminous flux. In outdoor installation, lamps without amalgam are preferable as they turn on better and give more light at lower temperatures.

Fluorescent tubes
Fluorescent tubes T5 FDH: These fluorescent tubes with diameter = 16 mm have been designed so their length fits a 600 mm modular ceiling. The lamps are available in two different designs, HE (High Efficiency) with maximum luminous efficacy and HO (High Output) with maximum luminous flux. All outputs in the HE range have the same fluorescent lamp luminance, while this value varies in the HO range. The fluorescent lamps are designed to give their maximum luminous efficacy at approx. 35° C ambient temperature, corresponding to the normal temperature in an IP20 luminaire. Always operated with an electronic ballast, and also capable of dimming with a special electronic ballast. Circular fluorescent lamp T5 FC: Fluorescent tube diameter = 16 mm in three diameters and four outputs. Unlike the normal T5 fluorescent lamps, these lamps are designed for a 25° ambient temperature. These tubes are always operated with an electronic ballast.

Halogen incandescent lamps
Halogen incandescent lamps 12 V: Available in many different designs and outputs, and have many good properties, such as excellent colour rendering, relative cheapness, good service life, facility for dimming etc. Their disadvantage is a relatively poor energy efficiency. Halogen incandescent lamps 230 V: These halogen incandescent lamps have the same benefits as ordinary incandescent lamps but are more efficient and have longer service life. Available in outputs up to 250 W. Their disadvantage is again a relatively poor energy efficiency.

Incandescent lamps
A light source with many good qualities, good colour rendering, low price, requires no ballast, easy dimming etc. Limitations: Low energy efficiency and short service life.

Metal halide
Metal halide MT/MR/MD 35-150 W: These light sources (Mastercolour) have a ceramic burner which results in colour temperature diffusion of less than ±200K. The white ”sparking” light from the light source is very reminiscent of the 12 V halogen incandescent lamp but has a number of advantages such as energy efficiency and long service life. MT lamps are available in a UV stop design. The MT light source requires a luminaire with protective glass. MR lamps have an integrated reflector with various diffusion angles and dimensions and with integral protective glass. At the time the catalogue went to press only a few models and outputs of metal halide lamps allowed dimming. They are not presented in the catalogue. Limitations: Warm-up period of 2-3 minutes. Restarting the hot lamp takes up to 15 minutes.

High pressure sodium 
The “White Son”, SDW-T (35-100 W) lamp has a colour temperature close to an incandescent lamp and gives excellent rendering of most colours. Other advantages are high efficiency and long service life. Limitations: These high pressure sodium lamps do not allow dimming. They have a warm-up period of approx. 4 minutes and restart of the hot lamp takes up to 2 minutes. Other high pressure sodium lamps normally have high luminous efficacy combined with a low colour rendering index. Limitations: As above.

Mercury lamp
The mercury lamp is an excellent light source for outdoor use, but does not have such good colour rendering properties. Limitations: The mercury lamp does not allow stepless dimming. It has a warm-up period of approx. 5 minutes. Restarting the hot lamp takes up to 2-3 minutes.

Induction lamp
QL lamp: This light source system has many excellent properties such as high luminous efficacy, good colour rendering, direct lighting and relighting, etc. However, its most important advantage is the very long service life of 60-80,000 hours.


Luminous efficacy
The luminous efficacy of a light source is the ratio between the luminous flux and the electrical output used. Luminous efficacy can be determined for the light source or for the system (light source plus ballast). The unit for luminous efficacy is [lm/W]. Note that the stated value of luminous efficacy in the tables on the following pages applies to the light source and takes no account of ballast losses.

Lamp life
The number of hours at which half of a large number of monitored light sources have failed. Used for incandescent and halogen lamps.

80 % service life
When 80 % of the original luminous flux from a lighting installation remains. The depreciation in luminous flux is due to reduced luminous flux and failed light sources.

General colour rendering index, Ra
Colour rendering is a measurement of a light source’s ability to correctly render test colours in relation to a specific reference light. The Ra index for indoor lighting should be over 80 and for good colour rendering over 90. The value for maximum colour rendering is indicated as 100.

Colour temperature, K
The colour temperature indicates the colour shade of the light source and varies in the range 2000-7400 K. 3500-4000 K is regarded as neutral white. Colour temperatures lower than 3500 K are experienced as warm and those higher than 4000 K are experienced as cold. ActiViva TL5 fluorescent lamps for 8000K and 17000K contain 25 % and 85 % respectively more blue light than daylight. A higher amount of blue light has a positive effect on our well-being. Equivalent colour temperatures are indicated for fluorescent lamps and discharge lamps.

Colour code
Lighting source manufacturers indicate the colour properties of the light source with an international colour code consisting of three digits. The first digit stands for the colour rendering of the light source and the two final digits the colour temperature in Kelvin, arrived at by dividing the colour temperature by 100. A light source with colour code 830 has a general colour rendering index between 80-89 and a colour temperature of 3000 K.

LED is an abbreviation for Light Emitting Diode. An LED is a semi-conductor which when electrically stimulated emits light (also called electro-luminescence). The colour of the light emitted depends on the material used in production. The basic colours manufactured are red, orange, green and blue. White light is obtained either by mixing three different colours: red, green and blue (RGB) or more usually, by using a blue LED with a fluorescing powder which converts part of the radiation to yellow light. The result is a white light.

The production of LEDs results in a large variation of both colour temperatures and luminous fluxes. The variations are so large that it is absolutely necessary to select a limited range. This choice is called the selection of the binning. The LED manufacturer divides up the production into several groups depending on performance. The narrower the choice made, i.e. accepting LEDs only from a single binning, the more even the quality of the products will be. The disadvantage is that the price may go up and availability fall. Normally therefore an attempt is made to select and accept LED's from a number of adjacent binnings.

White LEDs
White LEDs are available with warm, neutral and cold colour temperatures (2700-8000K). The colour rendering index Ra may vary from 70 to over 90, depending on choice of LED. An LED with a low colour temperature, i.e. a warm light colour, has a higher Ra value compared to an LED with a high colour temperature. Luminous efficacy from LEDs is constantly being improved and development is very rapid.

Luminous efficacy from white LEDs will soon be up to 100 lm/W, i.e. a figure corresponding to ordinary fluorescent lamps. LEDs with high colour temperature, i.e. a cold light colour, have a higher efficiency than corresponding LEDs with a low colour temperature. The reason is that white diodes are in reality blue diodes with a very high colour temperature.

The light distribution from an LED can be controlled and guided by use of reflectors, lenses or some kind of diffusing material. Lenses are usually directly tied to the make and type of LED.

Service life and durability
An LED has a long service life when used correctly. LEDs rarely fail. What happens instead is that the luminous flux decreases until it finally disappears. Datasheets for LEDs indicate service life as the level where 70% of the luminous flux remains (L70). This service life is around 35,000-50,000 hours for operation within the limits set by the manufacturer. One decisive parameter for both service life and luminous efficacy is that an LED is operated at a reasonable temperature.

LEDs emit neither ultraviolet (UV) nor infrared (IR) radiation. LEDs contain no moving or sensitive parts. They also contain no environmentally dangerous items, which simplifies recycling.

Heat development
The requirements for correct design of LED cooling are very high indeed, and are implemented by means of heat sinks or other ingenious design solutions. In the development of LED products the same high requirements for temperature margins are applied as for other products containing some form of electronics.

LEDs require specially adapted ballasts, often called drivers, which convert the 230V mains voltage into suitable parameters for LED operation. One type of LED operation is called constant current operation. Here the connected LEDs are operated at a constant current, normally 350 or 700 mA, though some LEDs can be operated at higher currents. Voltage must be kept lower than 48V DC. This type of operation permits serial connection of LEDs. The total output per circuit must be adapted to the size and specifications of the driver.

Systems consisting of battens or self-adhesive belts containing a large number of LEDs are usually operated at constant voltages of 8, 10, 12 or 24V. Several battens can be connected in parallel to a common driver. It is worth remembering that the voltage field in the wires is calculated in exactly the same way as in conventional extra-low voltage installations.

Regardless of the type of operation it is important that the driver is correctly adapted to the type of LED being operated. Polarity is important too, as the LED is operated by direct current (DC). The wrong choice of driver will damage or destroy the connected LEDs. Drivers also need to ensure electrical separation/insulation from the mains voltage. LED modules without protective insulation can thus be touched without risk of electric shock.

The professional dimming of LEDs is performed by the use of drivers with pulse width modulation (PWM). In this case LEDs are operated with a technology consisting of variable frequency square waves. Connected LEDs are turned on and off at high frequency, thus reducing the light level. Operating devices with PWM are available with various types of control interface such as DALI, DSI, DMX512 and SwitchDim.

It is important to follow the polarity. Incorrectly connected LED’s may be destroyed or damaged. In PWM units the maximum cable length is usually indicated. Longer wires can create problems in the control system or generate EMC problems, i.e. interference. In constant voltage circuits, attention must be paid to voltage falls. In constant voltage operation the LEDs are connected in parallel to the driver. In constant current operation the LEDs are connected in series to the driver.

Phasing out of incandescent lamps
On 18 March 2009, the EU Commission issued a directive on the ecological design of light sources, which involves the phasing out of the traditional incandescent lamp. The reason for the EU decision is simple – incandescent lamps are not energy-efficient. Of the input energy, only 5% becomes visible light, while the rest turns to heat. On 1 September 2009 manufacture within and import to the EU of all matte incandescent lamps was prohibited, together with clear incandescent lamps of 100 W or over. However, these lamps are still in use and shops are allowed to sell their remaining stocks. The full phase-out should be complete in September 2012, when the manufacture and import of the remaining 15 W incandescent lamps is prohibited. In other words, consumers have a few years to get used to this major change. In Sweden, phasing out of incandescent lamps will, according to lighting industry calculations, give energy savings of 2TWh and in Europe it will bring reductions in CO2 emissions of 0.7 million tonnes.

Under the proposal, phasing out will be implemented to the following timetable

Matte lamps: 
- 1 September 2009, ban on all matte incandescent lamps.

Clear lamps:
- 1 September 2009, ban on clear incandescent lamps of 100 W or more.
- 1 September 2010, ban on clear 75 W incandescent lamps.
- 1 September 2011, ban on clear 60 W incandescent lamps.
- 1 September 2012, ban on clear 40 and 25 and 15 W incandescent lamps.
- 1 September 2013, enhanced requirements for performance of low-energy lamps and LED lamps.
- 1 September 2016, enhanced requirements for halogen lamps and all lamps > 60 lm.





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