Earlier this year there was some TPS cable released on the New Zealand market that had configurations dissimilar to those generally supplied in New Zealand. Investigations and testing carried out by the Energy Safety Service (ESS) have shown that some of these cables have serious safety deficiencies, as well as a number of other recognizable compliance failures with the applicable cable standard.
Testing on samples of the cables indicated that the cables were not compliant with the ageing tests of the applicable standard, and after ageing, exhibited hardening of the insulation and sheathing. In the case of the TPS cables under investigation, no supplier of the cable has been able to provide ESS any evidence of their cable’s compliance with a recognized safety standard.
This is a most undesirable failure as it means that these cables when operated at their full rating will fail in a similar manner to the old TRS cables. The ESS investigation is continuing and further testing is being programmed. Following the completion of the investigation, a range of enforcement actions will be initiated by ESS against the parties involved.
The ESS is concerned that a number of electrical workers have installed these cables without verifying their suitability, despite the cables having readily identifiable compliance defects.
The outcome of the ESS investigations is likely to be a prohibition on these cables remaining in service if they are being operated at their full rating. Installers therefore may be required to either remove these cables from service or reduce the rating of the relevant protective devices.
Compliance with appropriate standards
The ESS believes that licensed electrical workers should take all reasonable steps to ensure that any equipment they install and certify is safe.
The ESS also considers the installation of unsafe electrical equipment by electrical workers to be a competency issue.
Consequentially the ESS will lodge complaints with the EWRB where it believes that an electrical worker has not taken reasonable steps to ensure that equipment they have installed and certified is safe.
As a result of these investigations, it is likely that the ESS will promulgate its expectations of electrical workers and suppliers of electrical equipment in respect to their safety obligations.
How to verify that equipment is safe to install
A considerable amount of material used in electrical installations is made to an applicable standard as a means of indicating safe use in an electrical installation. Such material is usually either marked on the equipment or the associated documentation indicated compliance with a standard to which the equipment is manufactured.
The Electricity Regulations 1997 and/or AS/NZS 3000 detail applicable standards that, if installed to the manufacturers’ recommendations or instructions, will provide safe installation. If there is no standard marking on the equipment or associated documentation, careful checking is required of any equipment to ensure that it is able to comply with the fundamental safety outcomes required. If in doubt, make such enquiries as required to verify that the equipment is safe to use in an installation, or alternatively, don’t use equipment for which you cannot verify its safe operation when installed.
Regulations amendment
The ESS begun the preparation of an amendment to the Electricity Regulations to update references to a number of standards and codes and to address a range of technical and administrative issues.
This amendment is likely to take effect early in the New Year 2005.
(NB: These items have been brought to the attention of the New Zealand Institute by the ESS and are presented here for the information of members.)
Source-Electrical Technology magazine. December/January 2004/2005 issue.
