A GUIDE TO INSTALLATION
Legal aspects, DIY Lighting, Extra low voltage lighting, Drivers, dimmers. Plus, Positioning light fittings: chandeliers & pendants, wall lights, downlights, bathroom lights.
New Zealand laws (The Electricity Act) restrict the homeowner to doing only certain kinds of electrical work. It is recommended that all electrical work is done by a registered electrician. A registered electrician must be able to produce their electrical registration card on request. For new builds electricians are required to complete a Certificate of Compliance (COC) and leave a copy of this with the homeowner. These are legal obligations aimed at protecting life and property and it is important to comply with them.
The homeowner can install extra low voltage lighting (usually 12 or 24volts) such as that supplied from the secondary (extra low voltage) side of an isolating lighting transformer or driver. The homeowner cannot connect the other (primary) side to the household electrical system unless it is fitted with a compliant plug.
The homeowner can attach shades and to light fittings but should ensure they are switched off first.
Read all Installation instructions supplied with Lighting and electrical products thoroughly.
Extra Low Voltage Lighting
Extra low voltage lighting is used for two main reasons, it is electrically safe, especially in wet areas or areas where wires are more likely to be uncovered, such as in gardens.
One type of extra low voltage lighting that is often installed by homeowners is garden lighting. With extra low voltage exterior lighting, lights can be connected together with purpose-made 'ground burial cable' but care should be taken not to bury this where it could get damaged by a spade. The electrical codes still prevent homeowners from connecting the mains voltage side of the transformer or driver to the household electrical system.
Transformers and Drivers
Transformers and drivers are devices that transform one voltage to another. In the case of lighting transformers, they 'drop' the 220- 230-volt mains power down to 12 or 24 Volts. It is important when choosing lighting transformers to ensure they are adequately rated for the number of lamps to be connected to them. (Transformers are rated in 'va', which is volts multiplied by amps (current), which equals watts).
There are two types of transformers, electronic and wire wound. Electronic transformers are lightweight and slightly more efficient than wire wound and produce very little heat. The drawback with these is that very few can be dimmed with conventional dimmers and if the wires from the output are too long they can interfere with radios and TV sets. Conversely, wirewound transformers are bulkier, heavier and produce some heat but can be dimmed on conventional dimmers.
An Important point to note is that underfloor or ceiling insulation, such as batts should not cover lighting transformers or drivers unless it is said safe to do so or if a recessed lighting fixture has a rating of IC, IC-F or IC-4. Please read and follow instructions provided with electrical products thoroughly.
Dimmers are perhaps the most useful devices for altering the mood of a room when lit. Dimmers come in different power ratings and they must be adequately rated for the number of lamps they are dimming. An electrician can advise on this. Today's dimmers are quite compact, and it is possible to fit three dimmers, and their on-off switches, on a single domestic switch-plate.
Positioning Light Fittings
Chandeliers and Pendants
These types of lights can be quite robust and heavy. Good quality chandeliers are made of lead crystal and usually lots of it, so need proper fixing to substantial ceiling timbers. If you are in the building process you might want to think about if extra timer beams are required for heavy lighting fixtures. It is unwise to use toggle bolts to fix Heavy pendant lights, as it is easy to dislodge them during cleaning or when changing bulbs. In some cases, you may need to retrofit extra timber into a ceiling if there is not adequate bracing where you wish to install your heavy decorative lighting fixture.
The style of a fixture has an important bearing on how it should be mounted. For instance, a single bowl or contemporary disc feature will be more appealing at a lower height than a large chandelier, which should be mounted higher to show off the intricate cuts of the crystal.
The main considerations when positioning wall lights are clearances from ceilings, furniture and drapes, and avoiding uncomfortable glare. The general rule is to keep wall lights above eye-level and bear in mind that there may be taller people in the room at times. If wall lights project light upward only “up lights” they should not be too close to the ceiling as, it would create a 'hot spot' and not distribute light over as large an area. Large wall lights often require an extra timber batten in the wall to achieve the desired position.
If installed in the wrong place downlights can be a hazard, because of this there is a code of practice to deal with potential problems. Care should be taken when locating downlights in the home and a registered electrician should be employed to ensure this is done in accordance with the code. This code stipulates the minimum distances that downlights must be installed from thermal insulation and wooden building elements. It also stipulates specific types of downlights that should be used in moisture-laden areas such as kitchens, bathrooms and laundries, so as to avoid moisture being drawn into ceiling cavities and the like. With downlights, as with other light fittings, it is important not to exceed the maximum wattage recommended for the lamp as this increases the risk of overheating.
When positioning downlights, it is wise not to put them too centrally in a room that has no peripheral lights, such as wall lights. This avoids having totally dark walls, which can create an impression of a small, closed-in room. In general, a room requires more downlights, than say pendants, to provide the same light level. This is because they only project light downward, which leaves areas unlit or not lit as much. As a general rule of thumb, you should allocate one downlight for every 4 square metres of room space in a home with an average ceiling height of around 2.4 metres high. Manufacturers' installation instructions often give more detailed guidance on this. This spacing can be decreased where there is supplementary lighting such as wall lights or pendants.
'Swing and Rotate' downlights have an adjustable aiming capability, which gives them greater flexibility in terms of directing the light from them and are ideal for skillion roofs or raked ceilings.
Remember though, downlights must be installed by an electrician in order to avoid problems and ensure compliance.
Bathrooms and Laundry Lights
Bathrooms and laundries are considered 'damp areas' in the electrical codes of practice and special rules apply to ensure electrical safety is maintained.
In summary, the code defines 'zones' around sinks, baths, and showers in which electrical equipment must not be installed or, in which special damp-proof products must be used. This part of the electrical code is designed to protect people from inadvertent and accidental contact with live electrical products and protect life.
Again, you must use a registered electrician when positioning any electrical products in these areas, including lighting.