Telecom has received reports from its service contractors that there have been increasing cases of telephone or data jackpoints being mounted on a common faceplate with 230 V outlets, switches, lamp modules, etc. This practice is in conflict with clause 3.2 of the joint Australia/New Zealand Standard ASA/NZS 3112, “Approval and test specification - plugs and socket outlets”.

While this is physically possible with the now widely-used modular electrical components, mixing TNV and LV on the same faceplate brings the risk of 230 V contact with the telecommunications wiring. Telecom is obviously concerned at any risk of 230 V passing into the Telecom cable network, potentially creating a shock hazard for staff far from the actual point of contact.

Telecom’s Code of Practice for residential premises cabling, PTC 103, requires a 200 mm horizontal separation between 230 V fittings and jackpoints connected to the Telecom network unless there is a physical barrier, such as a wall stud, between the two classes of hardware.

From purely practical viewpoints, any jackpoints mounted on the same faceplate as a 230 V fitting and failing in service cannot be replaced by Telecom contractors, most of whom do not hold electrical registration. Even mixing jackpoint modules with other ELV modules, such as co-axial connectors, aerial sockets, etc, complicates servicing, as Telecom’s contractors do not usually hold stocks of jackpoint modules and can only replace a failed module with the closest Telecom equivalent jackpoint.

TNV/ELV mixing will arise with RJ45 modules, which we expect to often be fitted in a common faceplate with a coaxial “F” connector, but this does not introduce any potential hazards. Also, as Telecom’s wiring maintenance service currently applies only to the standard 6-pin BT-style sockets, it is expected that most RJ45-based home installations, like commercial installations, will be maintained by an independent contractor.

Electricians probably do most telecommunications wiring in new homes these days, as it is most convenient to do this work as part of the electrical sub-contract. While their 230 V wiring is required to comply with AS/NZS 3000, this standard is not particularly clear on segregation requirements. Hopefully, this point will be addressed at the next revision of the Standard.