What is Electrical Testing?

Electrical Testing is necessary for the safety of persons using the equipment and for the proper discharge of the obligations of employers and employees, according to legislation matters. 

Why should I do electrical testing?

It is the duty of the employer to ensure, so far as it is reasonably practical, the safety, health and welfare at work of employees including maintenance of the work place and its equipment, access, work practices, instruction and training, provision of protective clothing and emergency routines. 

Who should do the electrical testing?

Electrical Testing is carried out by staff members who have undergone training in the use of electrical testing equipment and determination of results. Both visual and electrical testing of appliances should be carried out by a person with the knowledge of practical experience of electricity and its hazards i.e. qualified electrician with the relevant City and Guilds qualification in Inspecting and Testing of electrical appliances. Since the person or duty holder must make judgments on the appropriate level of testing required they must understand the operating principles of each appliance and have adequate knowledge of the relevant safety standard. They are certified as competent persons for electrical testing. 

Who will be held responsible for the electrical testing?

The Regulations specify that employers and the self-employed are liable for the correct use and maintenance of all electrical appliances at their place of work. Employers in this sense include those people accountable for the management of offices, factories, shops, hospitals, hotels, and all other buildings used by the public. Those companies engaged in the manufacture repair, hire or resale's of electrical appliances are also legally responsible for the safety of all items they supply. 

What tests must be performed in electrical testing?

1- The Environment (where the work place is harsh or hazardous)
2- Good Housekeeping Check (the electrical equipment is used in accordance with the manufacturers instructions)
3- Suitability of electrical equipment (If the Inspector or tester considers that the equipment being inspected and/or tested is not suitable for the environment or the nature of the work being undertaken.)
4- Disconnection of Equipment (This means of isolation from the electricity supply must be readily accessible to the user.)
5- The Condition of the Equipment (Before inspecting the equipment ask the user whether they are aware of any faults and whether it works properly, the user is familiar with the equipment and may be aware of any intermittent faults.)
6- The Plug and Sockets Testing
7- Earth continuity testing (This test can only be applied to class 1) (a) relies on a connection with earth for its safety (protective earthing) and or (b) needs a connection with earth for it to work (functional earthing).
8- Insulation Resistance Testing (For some types of appliances, insulation resistance is generally checked by applying a test voltage and measuring the resistance.)
9- Touch Current Measurement (This is an alternative to the in-service insulation test for use if the insulation resistance test cannot be carried out or gives suspect results.)
10- Functional Checks (In its simplest form a functional check is simply a check to ensure that the appliance is working properly)
11- Shock Tactics Testing (It has been estimated that around a quarter of reportable electrical accidents involve portable appliances or equipment.)
 

Which electrical things need to be tested in electrical testing?

1- All portable appliances need to be inspected and tested during their working life. In general a portable appliance is one which;
     (a) Can be carried from place to place between periods of use and
     (b) Is connected to a power supply via a plug fixed to a flexible supply cable
     (c) Any piece of equipment, which fits this description, needs to be inspected and tested regularly.
2-Infrared and Ultrasonic Scanning Testing
     (a) Electrical Switchgear & Equipment
     (b) Electrical Distribution Systems
     (c) Electrical Transmission Systems
     (d) Electric Induction Furnaces
     (e) Roof and Building Envelope
     (f) Electric Arc Furnaces
3- Circuit Breakers Electrical Testing
     (a) Power Circuit Breakers
     (b) Molded Case Breakers
     (c) Insulated Case Breakers
     (d) Medium Voltage Breakers
     (e) High Voltage Breakers
4- Electrical Equipments Testing
     (a) Switchgear Assemblies
     (b) Unit Substations
     (c) Power Centers & Motor Control Centers
     (d) Medium Voltage Starters
     (e) Generator Switchgear
     (f) Lightning Arresters
     (g) Control Devices
     (h) Electronic Over-current Devices
     (i) Ground Resistance Testing
     (j) Medium Voltage Contactors
     (k) Ground Fault Equipment
     (l) Transfer Switches
     (m) Emergency Power Equipment Generators
     (n) Cable Hypotential Testing
     (o) Protective Relays
     (p) Instruments and Meters
     (q) Bolted Pressure Switches

The electrical testing is carried out at regular intervals:

 Electrical Testing Environment

There should be adequate clear working space and the testing environment should be as earth free as possible, with a minimum of exposed earthed metalwork. Permanent test areas should be set apart by barriers to prevent entry, with suitable warning signs and green or red lights to indicate whether it is safe to enter the area and should be provided with an emergency stop button to cut power supplies in the event of an emergency.  The poster “Electric Shock: First Aid Procedures” should be displayed at a prominent location, giving emergency contact numbers. Temporary test areas should be set up in the same way where reasonably practicable.The floors and walls should be insulated; the floor with rubber matting (complying with relevant British Standard). The electrical supply should be via one or more isolating transformers. Pipe work, conduit, radiators, and structural steel work, socket outlets should be removed or shrouded with insulating material. Benches and other ‘furniture’ should be made of non-conducting material and legs and framework shrouded with insulating material to prevent contact. Where it is necessary to have a mains socket outlet connected directly to the supply, a Residual Current Device (Earth trip) should be installed. Soldering irons and task lighting should be extra low voltage and supplied from an isolating transformer.Each item under electrical testing should have it’s own test supply.Individuals carrying out electrical testing should be kept far enough apart so that they cannot touch each other, otherwise two undetected faults on each piece of equipment under electrical test could cause current to flow through both persons.Further precautions should include a non-conducting work environment (including bench, socket outlets and other service equipment) particularly where isolated supplies are not provided to each piece of equipment. These protective devices could be of a temporary nature and be fitted before testing commences. 

Electrical Test Equipment

Guidance Note GS 38 ‘Electrical test equipment for use by electricians’ provides guidance for electrically competent people involved in electrical testing, diagnosis and repair. 

System Of Work of Electrical Testing

Before electrical testing begins it is essential to establish that the test device, including all leads, probes and connectors, is suitably rated for the voltages and currents, which may be present. The equipment that is to be worked on must be safe for the intended test and the working environment must not present additional dangers. Appropriate precautions should be taken whilst electrical testing is carried out, as outlined previously. Test devices/equipment should be regularly inspected and, where necessary, tested by a competent person.