Make sure you’re taking care with your inspections

There are a number of pitfalls which can be avoided with care

In this guest article, our Associate Member takes us through the five most commonly missed observations they encounter during electrical audits on recently completed periodic inspection and tests

At its core, compliance auditing evaluates whether a housing organisation is meeting its regulatory responsibilities.

In terms of electrical auditing, this will include measuring the organisation’s performance in maintaining the housing stock against statutory and non-statutory requirements, such as those given in the EAWR 1989 and BS 7671.

Examples of the benefits of compliance auditing include:

An assessment of the organisation’s control systems to meet regulatory responsibilities and any recommendations for improvements where required
The evaluation of risk in respect to performance and potential negligence
The enhancement of credibility of the organisation’s electrical services.

So what are the most commonly overlooked things we find when carrying out such auditing on electrical documentation, such as the Electrical Installation Condition Reports (EICRs) received after periodic inspection and testing of an organisation’s properties?

Exposed basic insulation

First up, we have insulated and sheathed cables not taken inside an enclosure. BS 7671 Regulation 526.8 requires that cores of sheathed cables from which the sheath has been removed and non-sheathed cables shall be enclosed as required by Regulation 526.5.

Where issues concern the distribution network operators’ (DNO) or meter operators’ equipment, this should be reported to the relevant organisation by the person ordering the work.

Classification Code: A C2 may be awarded where the insulation is accessible to touch and/or there is potential for contact with metalwork, otherwise a C3 would generally suffice. No code need be awarded where basic insulation is undamaged and within a suitable enclosure, such as a lockable meter box in a satisfactory condition.

Compatibility of protective devices

The presence of differing manufacturer protective devices in a consumer unit is an observation that comes up regularly.

BS 7671 Regulation 536.4.203 requires that devices and components that are used in low voltage assemblies to BS EN 61439, such as consumer units and distribution boards, must only be those that have been declared suitable by the manufacturer of the assembly.

It is important to remember that this may include devices of the same manufacturer.

Classification Code: A C3, although this would be dependent on the potential for access to live parts and/or signs of thermal damage.

“Where issues concern the distribution network operators’ (DNO) or meter operators’ equipment, this should be reported to the relevant organisation by the person ordering the work”

Absence of warning notices

Check for warning notices! BS 7671 Regulation 514.13.1 requires that a durable notice to BS 951 with the words ‘SAFETY ELECTRICAL CONNECTION – DO NOT REMOVE’ shall be permanently fixed in a visible position at or nearby:

The point of connection of every earthing conductor to an earth electrode
The point of connection of every bonding conductor to an extraneous-conductive-part
The main earthing terminal, where separate from main switchgear.

Classification Code: Where a notice is absent, a C3 would be appropriate.

Thermal insulation

Compatibility of protective devices is key to a safe installation

Contractors often record 101 or 103 as a circuit’s reference method when encountering twin and earth cables but fail to comment on the ongoing suitability of the installed cables.

BS 7671 Regulation 523.9 refers to the installation of cables and a preference to avoid areas where cables are liable to be covered by thermal insulation. Typically shower, cooker and ring final circuits are subject to a reduction in current carrying capacity following the installation of thermal insulation.

Here’s one example: A 9.5 kW 230 Velectric shower has been wired in 10.0mm2 twin and earth cable and is run through a roof space. The design current is 41.3 A with an overcurrent protective device rated at 45 A. On inspection, thermal insulation has been added with a thickness greater than 100 mm. Using column 3 of Table 4D5 of BS 7671, the current-carrying capacity of the 10.0 mm2 cable is 36 A. Therefore, the conductor’s current carrying capacity does not conform with the recommendations of Table 4D5. Note: Additional rating factors and voltage drop have not been considered for the purpose of this example.

Classification Code: A C3 where no signs of thermal damage are observed upon inspection. Where signs of thermal damage have been found, a C2 would be appropriate.

RCD types

Finally, we frequently see the type of RCD not considered on a periodic inspection and test. BS 7671 Regulation 531.3.3 states that Type AC RCDs shall only be used to serve fixed equipment where it is known that the load current contains no DC components.

Classification Code: A C3 where equipment or an appliance is connected or could foreseeably be supplied via a Type AC RCD, however when under test if the RCD fails to operate a C2 would be appropriate. Where no DC components exist or are likely to be connected in the future and the RCD operates, no code need be awarded.

Avoiding the pitfalls

The classification codes suggested above are taken from recognised industry guidance, e.g. Electrical Safety First Best Practice Guide 4, Issue 7. This does not substitute the use of engineering judgement by a competent person undertaking periodic inspection and testing. To conclude, my three pieces of advice for contractors to avoid these, or any other missed observations, are:

Stay up to date with the latest industry best practice guidance
Educate yourself and staff with ongoing CPD
Seek support where needed – SELECT is always on hand!

CORGI Technical Services has been synonymous with safety for more than 50 years. Offering a range of safety services and expertise including auditing, consultancy and training, it works with housing associations, local authorities and facilities management companies, with extensive experience of electrical auditing across thousands of properties. Find out more at www.corgitechnical.com