Published:
27 January 2015
Category:
Industry News
Specifications for conduits for communications cabling have been clearly outlined in Australian regulations and standards for several years, however there’s confusion in the industry about the colour and use of conduit to house communications cabling in indoor and outdoor situations.
Below is a summary of some excellent guidelines from the Australian Communications and Media Authority (ACMA) to assist communications cabling designers and installers use the correct conduits for the long-term integrity and safety of communications cabling that are well worth knowing.
Conduit colour
Most countries, including Australia, use standard colours to identify hazardous services in conduits. This is summarised below in Table 1 from AS/CA S009:2013 ‘Conduit colours in accordance with AS 1345:1995’.
Colour Associated hazardous service
Orange AC Mains power
Yellow/yellow-ochre Fuel, process, toxic or medical gases
Silver-grey Steam
Brown Flammable and combustible liquids
Violet Acids and alkalis
Light-blue Compressed air
Conduits containing communications cables (indoor and outdoor) must not be of any of these colours.
Outdoor conduit colour
Non-metallic communications conduit for all outdoor use shall be coloured white or contain an indelible or durable continuous white stripe incorporated during manufacture. Conduit must also be legibly and durably marked 'COMMUNICATIONS'. Hazardous conduit must not be painted white and then used for outdoor communications cabling.
Indoor conduit/duct colour
AS/CA S008:2010 ‘Requirements for customer cabling products’ doesn’t specify an indoor communications conduit colour. Conduit can be any colour, provided it’s not a colour listed in Table 1.
While white conduit isn’t mandatory for indoor use, it is encouraged to reduce confusion as to what it contains.
Outdoor underground installations (AS/CA S009:2013 section 8.3)
Customer cabling installed underground must not be enclosed in conduit of a hazardous colour, except where:
- Parts of the conduit are fully encased in concrete or inaccessible under structural concrete. The conduit ends shall be durably made white and the conduit used exclusively for communications cabling.
- Conduit that doesn’t contain HV circuits and is sub-ducted by the cabler in a continuous run of insulating conduit complying with AS/CA S008 and IPX8 of AS 60529 in which the cabling shall be enclosed.
- Customer cable that doesn’t contain electrically conductive elements (e.g. optical fibre) that may be directly installed, or sub-ducted in insulating conduit (not prohibited colour), in an existing conduit containing a service listed in Table 1. Here the cable must be labelled at all access points with suitable warnings that it may contain hazardous light.
Outdoor surface installations (AS/CA S009:2013 section 17.4)
Where any outdoor surface cable is potentially exposed to direct sunlight:
- Exposed parts of cable shall be manufactured of UV-resistant material; or
- Cable shall be mechanically protected from exposure to UV radiation (e.g. in conduit).
Public roadway or footpath installations (AS/CA S009:2013 section 18.3)
Underground cable installed under public footways or roadways must be:
- Enclosed in compliant conduit at a minimum depth of 450 mm; or
- Covered by white marking tape that identifies the service and complies with AS/NZS 2468.1:1995 and is installed a minimum of 100 mm above the cable.
Aerial installations (AS/CA S009:2013 section 19.3)
Aerial-installed customer cable must comply with AS/CA S008 for UV resistance, unless the entire length of cable is protected against exposure to direct sunlight (e.g. totally enclosed in suitable conduit).