Frequently Asked Questions
What is a lighting control system?
In its simplest form, a manually operated On/Off switch. This very basic system can be extended progressively to provide comprehensive control of a single room or a whole building.
The system can be controlled by a combination of wall-mounting pushbutton controllers, presence detectors, daylight sensors and time-clocks.
Why use dimming controls?
A basic light switch provides either zero or 100% of available light, with no variation in between. Compare this with natural lighting which changes its colour, diffusion and brightness throughout all of every day. Introducing this concept of mood lighting can dramatically enhance the appearance of an area, while reducing energy bills and increasing lamp life.
Does dimming save energy?
Yes. In residential environments, a lighting control system will both save energy and increase lamp life.
Where daylighting and presence detection are utilised as part of a complete system in commercial projects, savings of up to 40% on an otherwise manually controlled system are achievable.
Can a lighting control system pay for itself?
Yes, and within a realistic period, dependent upon the type of system. Where daylighting and presence detection is utilised as part of a complete system in commercial projects, savings of up to 40% are achievable.
What light sources are dimmable?
Incandescent and mains voltage tungsten halogen, with no modification to the lighting fitting. Existing integral dimmers already built into these fittings must first be disconnected
Extra-Low Voltage (SELV) lighting may be dimmed providing the transformers are compatible with the dimming equipment
Cold cathode (Neon)
Linear and compact fluorescent, with analogue (1-10V) and digital (DSI and DALI) control gear
LED, with appropriate control gear
Some CFLs (compact fluorescent lamps).
Light sources which are not currently dimmable for practical purposes include Metal Halide, CDM, mercury vapour, low-pressure sodium vapour (SOX) and high-pressure sodium vapour (SON). Rako controls provide a switching unit to control these light sources as part of an integrated lighting control system.
Are CFL equivalents available for all incandescent lamps?
Not yet. The highest wattage CFLs currently available as replacements for incandescent lamps are rated at approx 32 watts, equivalent in output to a 150 watt incandescent lamp.
However, using CFLs as replacements for incandescent or tungsten halogen lamps can create problems as follows:
Physical size – CFLs may be physically bigger than the original lamp, and may not fit into existing luminaires
The lamp cap options with CFLs are limited
CFLs cannot be used in fittings with built-in presence detectors
The colour of the CFL can appear cold, particularly during warm-up.
CFLs have a perceptible warm-up period from switch-on, making them unsuitable for rooms used for short periods.
A pinhead-sized amount of Mercury is used in the manufacture of some CFLs, requiring their careful disposal, so while they may be more energy-efficient during their lives, their manufacture has a poorer environmental footprint than incandescent lamps.
Are all CFLs dimmable?
Not yet. Most dimmable fittings may be switched on at an intermediate level, but dimmable CFLs presently must be switched on at Full, and then reduced to an intermediate level. This makes them unsuitable for pre-programmable systems.
However, Rako Controls have recently introduced a ‘Green’ dimmer, specifically for CFLs, which can detect how recently the lamp has been energised. If the lamp is cold, the dimmer will switch the lamp to Full and then automatically reduce the output to the preset level.
If the lamp is still warm from a previous activation, the CFL will be brought immediately to the preset level.
Can a dimming system installed as part of an existing lighting installation?
Almost all dimming systems require data wiring, so with most dimming systems this is not possible, due to disruption and costs.
However, with a Rako Controls system, data wiring is not necessary. The dimming units are so compact that they can, in most cases, be installed into the ceiling void directly above the luminaire.
Must lighting in all parts of a building be dimmed?
No. The installed system can comprise of just one dimmer controlling one circuit with one pushbutton controller. If required in the future, the system may be expanded by just one dimmer at a time, all controlled by the same controller. One pushbutton controller can control a maximum of 15 separate circuits.