Do I have to install a downlight that can be covered with insulation?
No, there is no requirement in the standard that states that a downlight has to be covered with insulation. As long as it has been tested and rated and carries either a CA135 or CA80 classification then you can abut to the fitting only, leaving the top of the fitting exposed.
Does every downlight fitting have to be fitted with a thermal cut-out?
No, a thermal cut-out is not the only means of compliance, however they are an economical and reliable item frequently employed at the manufacturer’s discretion and primarily used to ensure a fitting achieves one of the above listed classifications. Some insulation providers have recommended using only fittings with thermal cut outs; this would appear to be a misguided recommendation. A classification as above is not dependant on the use of a thermal cut-out.
What are the new downlight classifications I should be looking for?
Downlight classifications as described AS/NZS60598.2.2 Amendment A
What do I need to know about insulation in the installation of down lights?
The majority of the market appears to be held by mineral glass fibre types; however insulation comprised of other materials such as polyester and natural fibre is available. These materials generally have a lower ignition temperature than glass fibre and they should be used only if the supplier’s performance specification indicates they are safe to use with the down lights of your choice. It has long been recognised internationally that 90degC has been a threshold below which building materials should not go with regard to ignition temperature. If in any doubt about the materials involved you should check and confirm with either the manufacturer of the insulation product or of the fitting itself, to ensure their product can be installed in accordance with the new standard. You need to check the insulation manufacturer’s instructions to ensure their product is safe when installed alongside fittings approved to the new classifications. In summary what does this mean for down light installations?
What happens if I cover a CA ‘abutted only’ rated down light?
Provided that the lamp in use complies with the manufacturer’s recommendations, a safe situation will be maintained. Under the new standard all fittings are tested under abnormal conditions which assume the fittings may at some point be inadvertently covered fully with insulation or other material or an incorrect lamp fitted. Covering such newly rated fittings, (although not hazardous to the installation) may however result in implications for the fitting itself. It is likely that short lamp life will be noted and nuisance tripping may occur if the fitting has a thermal cut-out or the fitting may fail completely, but in a safe mode. High wattage LED’s (for example) may operate at higher than designed temperatures which may then shorten the rated lamp life of the fitting (speak to the fitting manufacturer for more detail in this instance).