This type of electrical equipment is usually found on construction and industrial sites and is signified by a yellow plugs and cables. All PAT Testers will test 110V (Earth Continuity & Insulation only) when used in conjunction with an pat testing adaptor some dual voltage ones can test without. However some testers have a build in transformer which enables load and run testing of 110V equipment.

Commonly known as Amps or the symbol (A) is a measure of the amount of electric charge (current) passing a point per unit time.

Equipment that uses current to function other than a luminaire or independant motor.

Insulation applied to live parts to provide protection against electrical shock. This does not include insulation used exclusively for functional purposes.

Protection against electric shock is provided by basic insulation only. Sales of these items have been banned since 1975 and they should not be used in an industrial, commercial or domestic environment.

Class 01 have at least basic insulation around live parts for protection, they also have an earthing terminal on the appliance but only two core power supply cords without an earth protective conductor. They should not be used in an industrial, commercial or domestic environment.

Protection against electric shock is provided by a single basic layer of insulation around live parts and any also any exposed metal or conductive parts that can be come live if a first fault developed should be connected to to earth. There is no symbol for a Class I product so if no symbol can be found assume that the appliance is Class I.

Protection against electric shock on Class II Double insulated equipment is provided by either two layers of insulation (basic and supplementary) around live parts or a material called substantially reinforced insulation. There should be no earth protective conductor on a Class II appliance. Class II appliances are identified with a box within a box symbol.

Also known a SELV (Safety Extra Low Voltage) Appliances are supplied with a low voltage (less than 50V) and are supplied via a safety isolating transformer.

All products / appliances fall into one of the construction classes above. The PAT Testing procedure varies for different construction classes.

Or CSA in cables is measured in mm2 and is used along with the length of the cable to calculate the resistance of a cable at a given temperature. The larger the CSA the more amps can be carried down the cable.

Are designed for speed, appliance information such as: Appliance ID, Location, serial number and description can be entered into the tester. This information is stored in the tester and can be downloaded at a later date. Downloadable testers are used by companies who need a record of results on a PC and who are doing large volumes of testing. This procedure saves the PAT tester loads of time when having to repeat the test (Also see upload memory)

Also known as earth bond verifies the integrity (continuity and the resistance) of the protective bonding of the equipment (Class I) It is designed to transport dangerous electricity away from the appliance in the event of a fault. It is reccomended by the IET (Insitute of Electrical Technicians) that earth continuity is checked at 1½ times the fuse rating of the appliance. The recommended PASS allowance for PAT Testing is (

Is the leakage current flowing down the earth protective conductor when the appliance is turned on and powered up, the IEE Code of Practice calls this test the Protective Conductor Current Test, call 0113 248 9966 for a PAT Course and learn how to do this test safely.

Is not recommended for appliances that are "In service" Flash testing is a high voltage DC test (1500V Class I & 3000V Class II) Flash testing used to be common practice, nowadays it is only used by manufacturers, repairers and hire companies. A Flash test performed at the wrong part of an appliance can damage thyristors, speed controls on drills, integrated circuits etc.