We’ve created a PAT Testing Glossary to help you understand many of the terms you will encounter when testing your portable appliances.
Ampere: It is commonly known as an Amps. It is a measure of the amount of electric charge (current) passing a point per unit time.
Basic Insulation: Insulation is applied to live parts to provide protection against electrical shock. It does not include insulation used exclusively for functional purposes.
Earth Continuity: It is also known as earth bond and verifies the integrity (continuity and the resistance) of the protective bonding of the equipment. It is designed to transport dangerous electricity away from the appliance in the event of a fault.
Earth Continuity Tests: This test ensures that there is satisfactory connection between the Earth Pin within a plug and the case of the appliance. It is also referred to as an Earth Bond or Earth Resistance tests.
Earth Leakage: It is the leakage current flowing down the earth protective conductor when the appliance is turned on and powered up.
High Current: Testers can perform an earth continuity test above 20 ampere’s This test is designed to “stress” the earth conductor and simulate what would happen if a fault in an appliance had occurred.
Insulation Resistance: Insulation resistance is the alternating-current resistance between two electrical conductors or two systems of conductors which are separated by an insulating material.
Insulation Testing: Insulation testing is normally carried out at 500V and is a high voltage DC test which stresses the internal insulation of a mains power cable and if the appliance is turned on, then the insulation past the switch.
Polarity Test: The purpose of the polarity test is to ensure that single-pole switches, fuses and circuit breakers are connected in the phase (non-earthed) conductor, and verification of this connection.
RCD: RCD stands for Residual Current Device. They are a life-saving device which are designed to prevent you from getting a fatal electric shock, if you touch something live, such as a bare wire.
Supplementary Insulation: Supplementary insulation is independent insulation which is applied in addition to basic insulation in order to provide better protection against electrical shock.
Touch Current: Touch current is a test where 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 on the size of leakage which is allowed to leak from different types of electrical equipment.