Guide to Portable Appliance Testing - Instrumart

1 To Portable Appliance TestingThe word Megger is a registered A Guide to PAT Testing 1 Table of ContentsIntroduction ..2 What is Portable Appliance Testing ? ..2 Why Should electrical Equipment and appliances be Tested? ..4 What inspection and Testing Needs to be Done? ..6 What Types of electrical Equipment Need Visual Examination and electrical Testing ? ..6 Multiway adapters and GFCI Adapters ..7 Extension Cords and GFCI-protected Extension Cords ..7 Hand-held Equipment ..7 Portable appliances ..7 Information Technology (IT) Equipment ..7 Portable Equipment ..7 Static Equipment ..8 Fixed appliances ..8 Built-in Equipment ..8 Construction of electrical Equipment ..8 Class I Equipment ..8 Class II Equipment ..8 Class III Equipment ..9 Visual Examination and electrical Testing ..9 Frequency of Visual Examination and electrical Testing ..9 Operator Checks (Procedure) ..10 Formal Visual inspection (Procedure).

2 12 Combined Visual Examination and electrical Testing Procedure ..15 electrical Tests ..16 Earth Bond/Continuity Test ..17 Insulation Test ..19 Protective Conductor/Touch Current Measurement ..20 Differential Leakage Leakage Test ..21 Load Test ..22 Flash Testing ..23 Faulty or Damaged Equipment ..23 Missing Equipment ..23 Labelling ..24 Documentation ..24 Portable Appliance Testers Available from Megger ..25 Megger PAT320 ..25 Megger PAT450 ..26 2 A Guide to PAT TestingIntroductionWe live and operate in a world filled with electrical equipment and appliances . electrical things fill our homes, our offices, our manufacturing facilities and the places we go for leisure activity. Electricity poses dangers. Personnel can be injured, sometimes fatally, by malfunctioning electrical equipment. Fires caused by defective electrical equipment and appliances damage property and cause large financial losses for companies.

3 In addition, ours is a litigious society and lawyers are waiting for opportunities to file does an equipment rental company ensure that a piece of electrical equipment is electrically sound/safe every time it goes out to a customer? How do in-house tool cribs ensure that their electrical equipment is safe for the next person to use it? How do manufacturing companies ensure that the appliances and equipment they make have no dangerous electrical faults? Beyond the challenges of protecting personnel and property, many of our manufacturing plants produce electrical equipment for sale into the European Union that must meet European standards. While it is the responsibility of the European importer to ensure that imported items are safe to European standards, any Testing done at the destination can prove quite costly for the manufacturer when faults are found. Identifying problems at the manufacturing plant allows for faults to be fixed prior to shipping and number of European countries, including the UK, make extensive use of Portable Appliance Testing to ensure the safety of electrical equipment and appliances .

4 This booklet will provide a Guide to understanding Portable Appliance Testing and how/where it fits as part of an overall electrical safety program. While we use the term Portable Appliance Testing , a better description might be Portable electrical equipment is Portable Appliance Testing ? Portable Appliance Testing is the visual examination and electrical Testing of Portable electrical equipment used in industrial, commercial or public access areas and locations (including rented property) to ensure they are safe to use, and cannot present an electrical hazard to the operator or anyone in their vicinity. Among the issues that can arise A Guide to PAT Testing 3n Exposure to live, conductive parts due to damage to the outer casing of the Worn and/or frayed power Defective, loose or missing earth/ground Failure to identify and correct problems such as those listed above can result in the electrical equipment becoming a shock hazard or a fire risk.

5 Many of these problems can be identified visually, but still often go unreported. Internal faults often go undetected. Portable Appliance Testing involves performing a series of tests that, taken together, are designed to identify any faults or product defects that would otherwise not be detected. In addition to protecting personnel, regular safety checks of electrical equipment tend to increase the operational life of that equipment. A Portable Appliance tester (PAT) allows the operator to make a number of safety tests with a single instrument, including:Earth Bond and Continuity Tests To verify the integrity of exposed metalwork on grounded Test To check that equipment conductors are isolated from Current Test To check that the equipment case and all exposed metal parts are isolated from Leakage Test To measure the difference in current between live and neutral conductor during Leakage Test To check that the equipment case and all exposed metal parts are isolated from earth/ground, by use of a safe test voltages as an added protection against seriously faulted test Load Test An operational test to ensure the asset works as it should without drawing excessive current from the supply.

6 4 A Guide to PAT TestingExtension Cord and IEC Power Cord Tests To check extension cords and line cords for safe addition to these standard tests, some instruments will perform a flash test (hipot or dielectric strength test) to test breakdown voltage levels. This test is normally done on new equipment, articles that have had a major overhaul, or equipment in the rental Should electrical Equipment and appliances be Tested? The key word is liability. An employer or manufacturer should show as much concern about safety as does the legal system. The liability is with the employer or owner of a place of business, or public place, to ensure that all electrical equipment accessible by employees or the public is maintained in a safe condition. The liability is with the manufacturer of electrical equipment to ensure that the equipment is safe for those who operate it. The best way to ensure electrical safety is by routine visual examination, electrical Testing and documentation.

7 In the UK, the Health and Safety at Work Act and the Electricity at Work Regulations, while not specifically dictating that Portable Appliance Testing must be carried out, do state that all electrical systems (which include appliances ) must be maintained to prevent injury and danger. The Provision and Use of Work Equipment Regulations 1998 (PUWER 98), made under the HSW 1974 act, states: the provision and maintenance of a working environment for his employees that is, so far as reasonably practicable, safe, without risks to health, and adequate as regards facilities and arrangements for their welfare at work . Regulation 4(1) of PUWER 98 has a more direct meaning to Portable appliances , it states: Every employer shall ensure that work equipment is so constructed or adapted as to be suitable for the purpose for which it is used or provided. In the USA, the Department of Labor governs the Occupational Safety and Health Administration (OSHA).

8 electrical safety is addressed in rule 72:7135-7221 and the NFPA 70E electrical Safety Requirements for Employee Workplaces. The purpose of the OSH (Occupational Safety & Health) Act, 29 651 et seq., is ..To assure so far as possible every working man and woman in the Nation safe and healthful working conditions and to preserve our human resources. The requirements are regularly revised in accordance with the most current A Guide to PAT Testing 5practices and technologies, and in response to a request by those concerned to reflect the most recent editions of NFPA 70E and the NEC. The stated goal is to ..provide nationally recognized safe electrical installation requirements, and to assure that ..the requirements contained in that standard are current and at the forefront of electrical safety technology. The standard states that ..electricity is widely recognized as a serious workplace hazard, exposing employees to electric shock, burns, fires, and explosions.

9 Underlying causes are listed as ..work involving unsafe equipment and installations, workplaces made unsafe by the environment, and unsafe work performance. Hazards stemming from faulty equipment are further identified as ..faulty insulation, improper grounding, loose connections, defective parts, ground faults in equipment, unguarded live parts, and underrated equipment. Detailed information on all the definitions and full requirements of Portable Appliance Testing can be found in the Code of Practice for In-Service inspection and Testing of electrical Equipment (3rd Edition) (ISBN 978-0-86341-833-4) available from the Institution of Engineering and Technology ( ). Those environments where these regulations are applicable include any place where someone is employed, areas of public access, and rented accommodation of all kinds. The Code of Practice for In-Service inspection and Testing of electrical Equipment identifies that regular visual examination and electrical Testing of equipment is an essential part of any preventive maintenance program.

10 Records of maintenance, including test results, should be kept throughout the working life of the equipment to enable the condition of the electrical equipment to be regularly the USA does not have the level of regulation found in the UK, we are far more litigious. Implementing a regular inspection program that includes PAT Testing of electrical equipment and appliances will help protect personnel from shock hazards, facilities from electrically induced fires and businesses from litigation. For businesses that manufacture and ship electrical products to the European Union, PAT Testing at the factory will ensure that products shipped will pass import Testing and not become a costly problem. 6 A Guide to PAT TestingWhat inspection and Testing Needs to be Done?The dangers of contact with live electrical parts need no explanation to an electrician. However, the environments in which the majority of Portable appliances are used are not necessarily where operators would be aware of the dangers or the implications of damage to equipment.