The Institution of Engineering and Technology (IET), ‘Code of Practice for In-service Inspection and Testing of Electrical Equipment’ gives guidance on inspection and testing:
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User checks: Faults are reported and logged, and faulty equipment should be removed from service. No record is required if no fault is found.
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Formal visual inspections: Conducted by a competent person, the results of which, satisfactory or unsatisfactory, are recorded.
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Electrical tests: Conducted by competent person in the safe use of the test instrument and knows how to interpret results, which are recorded.
Electrical testing are means of determining whether maintenance is required.
Frequency of inspection and testing will depend upon the likelihood of maintenance being required and the consequences of lack of maintenance.
To comply with legal requirements a suitable and sufficient risk assessment should be carried out by the Electrical Equipment Inspection and Test Programme Manager on all electrical equipment to evaluate the frequencies between inspections and testing, as defined in schedules A and B.
User Checks
The most important check that can be carried out on a piece of equipment, particularly hand-held tools, is a visual inspection carried out by the user, each and every time the equipment is used.
User checks are limited to an external visual inspection without dismantling equipment or removing cover plates etc. User checks, before use, should as a minimum focus on looking for:
No signs of overheatingNo damage to the cable and/or plugNo damage to the body of the equipmentNo signs of exposed conductors.Not operated in a location that could cause damage to the equipment.Operation of RCD (where fitted) by using the in-built test facility. A within date test labelNo damage to socket outlet or fused connection unit Refer to Appendix 3 for a comprehensive check list.
Formal Inspections and Electrical Tests
All electrical inspection and testing should be performed by a person who is competent in the safe use of the test equipment and who knows how to interpret the results obtained, see Appendix 7 for training requirements.
The following steps shall be undertaken:
Equipment being employed to undertake electrical equipment inspection and testing must be suitably maintained and calibrated according to the manufacturer’s guidelines.
In-service testing must be preceded by a preliminary visual inspection, see Appendix 3, as described in the IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment.
Testing will involve the following:
Earth continuity test (Class I – earthed equipment only)Insulation resistance test. (Class I and Class II with unearth metal)Protective conductor / touch current measurement (if required)Functional check.Operation of RCD (where fitted).
Special care must be taken not to damage sensitive equipment during testing. In these cases, ‘soft’ earth continuity test and a reduced voltage or ‘soft’ insulation resistance test must be completed. Where possible, use labels as defined in Appendix 4, if not available a test label complying with IET code of practice may be used.
On completion of the equipment inspection and testing a durable, adhesive label of sufficient size will be fixed preferably to the lead near the plug or on the equipment to be visible and clearly indicate pass or fail, the date of test, validity period and individual identifier, plus a method of identifying test operative. All old labels must be removed from cables and equipment.
All equipment and test results will be held on an Electrical Equipment shared register held by the responsible Estate Services or Departmental Inspection and Test Programme Manager.
In the event of any item being found to be defective, it must be clearly marked with an adhesive red label, with a white cross and the wording “FAIL” or “FAILED”. The equipment shall be immediately withdrawn from use for repair or disposal, and the electrical equipment liaison officer and user informed of the reason for its withdrawal. See label example in Appendix 4.
Items that are purchased or manufactured in-house must be identified, registered and inspected / tested as appropriate, as defined in see 3.10 & 3.11.
It is the duty of the user to ensure that these inspections or tests have been carried out prior to use.
Some equipment may be difficult to inspect and test for operational reasons. Where this is the case, special arrangements need to be made by the Equipment Liaison Officer with the appropriate Estate Services / Department Programme Manager or Test Operative.
The frequency of inspection and testing, either schedule A or B, will be determined through a suitable and sufficient risk assessment of each electrical item, but factors influencing the decision will include the following:
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The environment: Equipment installed in a benign environment, such as offices, will suffer less damage than equipment in an arduous environment, such as construction sites;
- The users: If the users of equipment report damage as and when it becomes evident, hazards will be avoided. Conversely, if equipment is likely to receive unreported abuse, more frequent inspection and testing is required;
- Equipment type: Hand held equipment is more likely to be damaged than fixed equipment. If such equipment is also Class 1 the risk of danger is increased because safety depends upon the continuity of the protective conductor from the plug to the appliance.
- Equipment Construction: The safety of Class I equipment is dependent upon a connection with earth of the fixed electrical installation. If the flexible cable is damaged, the connection with the protective earthing arrangements can be lost. The safety of Class II equipment is not dependent upon the integrity of the electrical installation.
- Frequency of Use: Frequency of use of equipment is important, particularly where, mobile or hand-held equipment is concerned, because this may have implications for service life and exposure to possible damage.
- Type of Installation Method: Installation methods should be taken into account especially when assessing fixed equipment, because for example the isolator position and cable management can be important factors when assessing for risk. The type of protective device fitted in the distribution will also have a bearing.
- Previous Records where applicable, previous records of inspection, testing and maintenance should be used to evaluate the frequency of subsequent inspections and tests. These records will provide a history of the environment and user and how this affects the condition of the equipment within the environment.
More information on inspection and testing is available through the HSE publication, INDG236, ‘Maintaining portable electrical equipment in low risk environments.
