A simpler system can be used in areas where there is no need for lighting control or various forms of logic. This application describes two systems that can be used in lifts, for example.

In a lift it can sometimes be difficult in simple economic terms to justify investment in presence-controlled lighting. The investment cost using existing technology is too high in relation to the saving that can be made. This relatively simple system requires a small investment, which contributes to a shorter payback time, especially if the alternative is that lighting is left on all day.

Often the investment can be justified more easily by including other benefits in the costing, such as environmental savings and improvements in comfort. Future rises in energy costs, improvements in technology and falling costs of technology can also make it profitable to invest in lighting control by presence detection in premises of this type.

Lifts are “premises” through which many people pass each day. A dynamic system that is gentler on light sources is therefore to be preferred. The dynamic system requires that lifts are fitted with dimmable HF ballasts.

Light sources

In the first system, control is achieved by switching the supply voltage on and off. This means that all types of light fittings can be used, including light fittings with 50 Hz coil ballasts, HF ballasts or incandescent bulbs.

The second, dynamic system, requires light fittings with HF ballasts.

Detector placement

The diagram shows how the detector should be positioned closer to the lift door so that it will reliably detect when the doors are opened, so that the lights are switched on when someone enters the lift.

Control

Two systems are described in this application: one with non-dimmable light fittings and one with dimmable HF ballasts.

Dimmable light fittings

A dynamic system is the best solution in lifts, as it is gentle on light sources and light fittings. It requires dimmable HF light fittings that are controlled by an NV-2 level selector. The level selector switches between two preset lighting levels, around 80 per cent when people are present, and around 1 percent, the minimum idle setting, when the lift is empty. This makes it important to choose light fittings with an idle energy consumption that is as low as possible.

Non-dimmable light fittings

The system is fully automatic, which means that presence is detected by the IR detector when someone enters, and the lighting is switched on. When there is no longer anyone present the lighting is switched off after the delay set at the detector.

If necessary several IR detectors can be connected to the control unit (a maximum of four detectors can be connected).

The system is supplied direct with 230 VAC and feeds 230 VAC direct to resistive and inductive loads with a maximum rating of 2,300 VA. A contactor must be used if the load is higher. The control unit that replaces the contactors is mounted on a DIN rack in the electrical cabinet and is three modules wide. The unit is fused for the connected load, up to a maximum of 10 A.

The use of a low-current detector that can be connected using EKKX 1 x 4 x 0.25 mm2 cable eliminates the need to run two 1 x 3 x 1.5 mm2 cables via the detector. All that is required is a 12 VDC supply direct from the control unit to the detector. See the wiring diagram for the relevant system.

Information on current budget

The system is very gentle on light sources because it is never switched on or off. It also gives an energy saving of 20 per cent when the lighting is at its highest setting, and has very low energy consumption when the lift is empty. Maintenance costs are also reduced, as the light sources rarely need to be replaced.
Power is supplied at 12 VDC by a rectifier, such as EXE-2000. The detector is installed using the simplest possible cable type: EKKX 1 x 4 x 0.25 mm2.
For instructions on adjusting the IR detectors and level selector please refer to the manual that is supplied with the detector.