The stairway corridor is a closed area with access through a number of doors. This makes acoustic detection an ideal solution, as it is the only technique that allows lighting to be switched on before people enter the premises. In this angled stairway corridor, the section by the stairs and lift has windows that provide daylight. No lighting is required here during the day. The inner section has no windows and is dark in the daytime, so lighting must be switched on when presence is detected.

The light fittings in this corridor have dimmable HF ballasts with analogue control (1–10 V) and are divided into two lighting groups.

From past experience and from the technical viewpoint it would be a serious oversight not to install a “dynamic lighting control” system on new builds or renovation projects where it is possible to choose ballasts for the light fittings.
This approach is described in detail in the manual “Detection technology for improving energy efficiency” and in the brochure “Dynamic lighting control”. This method can be used for both acoustic control and for control with IR detectors.

Operation (See wiring diagram on following page.)

The system is divided into two areas that are controlled by channels A and B in the AD-600 acoustic detector. During daylight, channel A is overridden by a light sensor, which means that the lighting on channel A is not switched on when presence is detected. Channel B, which covers the inner part of the corridor, is also lit during the day when presence is detected.

Common operation of both channels

When someone enters the stairway corridor the lights are switched on at the normal level set by the “High” potentiometers in the NV-2T level selectors, e.g. at around 80 per cent. The lighting is kept at the 80-per-cent level for as long as presence is detected. When presence is no longer detected the lighting is reduced to the base level after the delay periods set for outputs A and B (around two minutes). This is set to around two per cent using the “Low” potentiometers in the NV-2T level selectors, so that the stairway corridor does not become completely dark.

If no presence is detected in the stairway for an extended period of one to two hours, which is set as the delay for the NV-2T level selectors, the lighting is switched off completely for the rest period. This avoids idle losses in the system and greatly reduces the number of times that the lights are switched on each day.

NOTE! For acoustic detection it is essential that the stairway corridor is closed, i.e. that all entrances and exits to other areas have doors that are normally closed.

See the wiring diagram below!

The lighting in the stairway is controlled by a separate system.

See applications 4A and 4B.

See also the power diagram below!

The NV-2T level selector is also available with DSI protocol (NV-2T DSI), but in simple installations such as stairways, garages and corridors, digital ballasts would be overkill. It is simpler and easier to troubleshoot installations that use analogue ballasts.

Placement of detectors

The AD-600 detector is mounted in a DIN rack in a cubicle. Each microphone can provide detection over an area with a radius of 10–20 metres depending on the acoustic conditions. For more detailed instructions please refer to the manual for AD500/600.

Information for current budget

Acoustic detector

Svenskt patent nr. 9201493-5, English patent no. 0659329
The acoustic detectors detect sound in two frequency ranges: inaudible infrasound at low frequencies (0–3 Hz) and audible sound at high frequencies (6–8 kHz). These frequency ranges are separated by a frequency range over which the detector is deaf. See the audiogram on the right.

There are two versions of acoustic detector: the AD-500 and the AD-600. The AD-500 has a sheet metal enclosure and built-in microphone. The AD-600 has a plastic enclosure for mounting on a DIN rack. An optional light sensor is available that overrides the light system when there is sufficient daylight.

See the relevant manual for details of adjustment and programming.

Power diagram, dynamic lighting control with two lighting groups in stairway
A day in September

The yellow area represents the energy consumption with conventional lighting control in accordance with the light source manufacturer’s recommended burn times.

The green area represents the energy consumption with dynamic lighting control installed.
The yellow area represents wasted energy cost!