BEAMA

28 November 2011

Keith Smith, BEAMA’s Deputy Director – Installation Sector, highlights the potential dangers of mixing devices/components of one manufacturer with the system infrastructure of another manufacturer. Only make selections based on the Assembly/System Manufacturer’s advice, he urges.

Most people in the trade are fully aware that they should specify, install and sell products, which are fully compliant with the requirements of the appropriate Standard Specification (BS or IEC) for electrical installation products. For example, miniature circuit breakers should comply with BS EN60898 and Residual Current Circuit Breakers with BS EN61008. For these and many other ‘discreet’ devices this is fairly straightforward, however, it may not be quite as obvious when selecting devices or components that are to form part of an assembly or system. BS7671 Wiring Regulations clearly state that installed equipment must comply with the appropriate British or equivalent Standard and also places a specific responsibility on the installer to take into account all manufacturer’s instructions. (Reg 510.3).

Recent incidents have highlighted a misunderstanding and potential dangers of mixing devices/components of one manufacturer with the system infrastructure of another manufacturer.

The most common example of this practice is when an installer tries to fit mcb’s from Manufacturer ‘A’ into the Consumer Unit of Manufacturer ‘B’. Assemblies such as consumer units, distribution boards and panel boards are tested with specific devices installed, invariably those of the same manufacturer. The testing and certification for the Assembly (i.e. Consumer Unit + Devices) is undertaken to BS EN60439-3, formerly BS5486, whereby the complete assembly is subjected to test at specified load conditions. Whilst BS5486 is now obsolete, there are many existing installations with assemblies complying with this standard where the issue of mixing different manufacturers devices equally apply.

Although devices may appear similar, their dimensions, technical performance and termination features are not necessarily compatible.
Assembly/System Manufacturer’s instructions will always state quite clearly that their product is fully compliant when using in conjunction with their specified devices/components.

If the installer does decide to mix components and assemblies, he should be aware of the following:

1. In all cases installing devices other than those declared by the assembly manufacturer invalidates any testing/certification and warranty originally supplied by the manufacturer.
2. It is the responsibility of the installer who intends to mix different manufacturers devices/components in an assembly, to undertake testing and ensure conformity with BSEN 60439.
3. If this is not done, there is a probability that, in the event of death, injury, fire and other damage as a direct result of a failure of this assembly, then the installer would be held accountable under health and safety legislation.

Whilst we have focussed here on a very obvious assembly (the consumer unit) there are many other ‘systems’ that carry the same words of warning, for example:

1. Cable Tray, Ladder and Mesh systems are designed to Standard Specifications that include load bearing requirements – using Manufacturer A ‘lengths’ (tray, ladder or mesh) with Manufacturer B fittings (struts, cantilevers, etc,) will incur the same consequences as the consumer unit above.
2. Flexible Conduit and Fittings are manufactured to exacting standards to provide quantified levels of Mechanical, Ingress Protection (IP) and Flameproof protection – using manufacturer A flexible conduit with Manufacturer B fittings will once again incur the same consequences as the consumer unit above.

Of course this responsibility is not just that of the installer, the Distributor or Wholesaler also has a responsibility under the General Product Safety Regulations to act “with due care”. They should be able to substantiate any advice related to interchangeability of devices/components in assemblies/systems. If the installer acts on a distributor’s advice, and in so doing produces a non-compliant assembly, then both the distributor and installer may be liable for any resulting consequences.

Unless the Distributor, Wholesaler or Installer is ready to invest significantly in the testing, certification and ongoing maintenance of ad-hoc combinations, the only safe way to guarantee compliance, retain warranties and access support services is to select based on the Assembly / System Manufacturer’s advice.