Portable Appliance Testing:

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

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

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

110V Appliance: 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.

Class I Construction:  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.

Class II Construction: 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.

Class III: 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.

Class 0:  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: 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.

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

Cross-Sectional Area: 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.

Downloadable PAT Testers: 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) 

Earth Continuity: 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 (<0.1Ω for the earthed appliance + cable resistance) 

Earth Leakage: 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.

Flash Testing: 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.

Insulation Testing: Is normally carried out at 500V and is a high voltage DC test that stresses the internal insulation of a mains power cable and if the appliance is turned on, the insulation past the switch. Certain testers are available with a selectable Insulation test (250V / 500V) to help test surge protected extension leads.

IT Safe: PAT testers that are "IT safe" perform a low current earth continuity test usually below 200mA and are ideal for Class 1 equipment with delicate electrical components.

High Current: Testers perform a earth continuity test above 20 Ampere's. This type of test is designed to "stress" the earth conductor and simulate what would happen if a fault with the appliance had occured.

Load & Run Testing: With the electrical appliance switched on, mains voltage powers up the appliance and some PAT testers then measure the electrical load of the appliance, typically in kW or kVA to see if the appliance is still operating as per the manufactures specifications.  

PAT Testing Adaptors: These are primarily used for checking earth continuity and insulation on PAT Testers that do not have the correct socket. Appliance adaptors and extension adaptors are available in the following sizes: 13A, 16A, 32A & 63 Amps and 110V, 230V and 415 Volts. 

PAT Testing Labels: There are many different types the most popular been the PASS Label these are attached to the appliance after it passes the visual inspection, electrical safety tests and functions correctly. They are normally green and white. Red and white FAIL labels are attached to unsafe appliances, they are red because that is a danger colour. The .

PAT Test Training Courses: Students learn how to inspect and test electrical equipment used in the workplace so they can identify safe and unsafe electrical equipment. The UK's leading PAT Test Training Course provider who can provide PAT Test courses at your site or at other venues throughout England Scotland and Wales is PAT Training Services Ltd based in Leeds.

Supplementary Insulation: Independant insulation that is applied in addition to basic insulation to provide better protection against a electric shock.

Touch Current: Also known as Touch Leakage Testing. During this test the electrical equipment is powered up and a measurement of any leakage of electricity at the outside of the case is measured, there are limits to the amount of leakage allowed to leak from different types of electrical equipment. The IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment contains tables showing the maximum Touch Current allowed from electrical equipment.

Multifunction Testers: 


Automatic Loop Evaluation: Some testers have built in loop impedance values that allows an automatic evaluation of an earth fault loop path, in comparison  to the values stated in BS7671:2008. Normally notified by a  'Pass' or 'Fail' indication on the screen of a multifunction tester; this saves you having to refer to the wiring regulations to see whether the loop test that you have just undertaken is of a satisfactory impedance value.

Automatic RCD Testing: Automatically conduct RCD tests at both 0⁰ and 180⁰ polarities, at 0.5x, 1x and 5x of the RCD's trip current rating at the push of a button. A very useful, cost effective feature, saving you from conducting all of the individual RCD tests manually, and then having to move between your tester, and the consumer unit for each individual test. 

Bluetooth Communication: Wirelessly transfer your test results by connecting a multifunction tester to certain PDA's, your laptop or PC. 

Data Input Facility Inbuilt: Insert data into a multifunction tester. Input client details, supply type characteristics, or even programme specific test sequences to suit individual requirements. Data entry is conducted using a QWERTY keypad on a tester, or by interacting with a touchscreen interface. 

Downloadable Multifunction Tester: Download electrical test results from an installation via RS232 (Serial) or USB to certain PDA's, your laptop or PC. Your results can then be recorded into optional software packages so that you can quickly print test results off into certificates in formats such as ECA, NAPIT, NICEIC and IEE Stationary. 

Earth Spike Testing: An earth spike (rod, electrode, stake) test kit will enable you to test the resistance of the ground for a prospective location of an earth rod. This is an IEE approved method, of which is demonstrated in the IEE Guidance Note 3 publication. It will save you installing an earth rod, and then  testing the rod to find out that you have installed it into a area of high, non-compliant, resistance. 

No-Trip Loop Testing: In todays world where RCD's are becoming more and more popular, it is majorly beneficial to be able to carry out loop test (Zs), without tripping a residual current operated device, such as an RCD, or RCBO. A loop test is carried out at varying amounts of current, some testers carry these tests out an extremely low currents, which will bypass the tripping current of an residual current device. 

Phase Rotation Testing: Regulation 612.12 of BS7671:2008 states 'It shall be verified that the phase sequence is maintained in an installation'. A meter with a phase rotation utility enables you to make sure that the polarity of a multiphase system is what it should be, and that line 1 is in fact line 1 throughout your installation for example; thus complying with regulation 612.12.

RCD Ramp Testing: RCD ramp testing is a test function that will slowly ramp up the current between line and CPC conductor, until the residual current device (RCD, RCBO), trips. After the test has been conducted, the current required to trip the residual current device is then displayed, which can then be used to find the cause of an RCD which is, perhaps, nuisance tripping a circuit. 

RCD Type B Testing: Type B RCD's are residual current devices that are designed to detect high frequency AC and pure DC earth leakage currents. Although the devices themselves are fairly rare, some photovoltaic systems, which are becoming ever more popular in the UK installation market, feature these type B RCD devices, primarily before the introduction of newer inverters, that carry the necessary protection to rule out using a type B RCD. Be sure to choose a tester that has the capability of testing type B RCD's, should you require the function. 

Remote Test Probe: A remote test probe is an electronic test remote to help conduct continuity, and insulation resistance testing easier, by placing the 'test' button in your hand. This makes testing accessories such as ceiling pendant drops far easier, as you dont have to hold two or three leads in one hand, and then reach down to your meter with another, to press the 'test' button.  

Software Included: By installing software on your chosen device, you can complete all of your electrical testing on your laptop, PC, PDA or other modile device, and then print the results off into certificates in formats such as ECA, NAPIT, NICEIC and  IEE Stationary. Using a software package, coupled with a tester that can download results, will dramtically decrease the time that it takes for you to complete test certificates. Moreover, choosing a tester with software included will typically save you a lot of money, rather than purchasing software seperately in the future.