Domestic Electrical Installer – Essential Electrics

25 vocabulary flashcards summarising key terms, devices, standards, and safety practices from the Essential Electrics module for domestic electrical installers.

Voltage Tester (GS38-compliant)

Hand-held indicator used to verify the presence or absence of voltage; must meet GS38 safety requirements.

Proving Unit

Portable device that supplies a known voltage so a tester can be checked before and after use.

Consumer Unit

Main distribution board in a dwelling containing fuses, circuit breakers, and RCDs.

Ring Final Circuit

Socket-outlet circuit wired in a closed loop so conductors form a ‘ring’ back to the consumer unit.

Isolation

Action of disconnecting electrical equipment from every source of energy so it cannot become live.

Isolating Device

Switch, fuse, MCB, RCD, etc., that meets British Standards and provides the required contact gap for safe isolation.

Miniature Circuit Breaker (MCB)

Automatic protective‐switch device that trips under overload or short-circuit conditions.

Residual Current Device (RCD)

Protective device that disconnects a circuit when it detects an imbalance between live and neutral currents.

BS EN 60947-3

Standard specifying construction and performance requirements for low-voltage switchgear used as isolators.

Dolly-Lock

Locking clip fitted to a circuit breaker toggle (‘dolly’) to prevent it being switched back on accidentally.

Secure Isolation

Practice of ensuring a de-energised circuit cannot be re-energised, e.g., pocketing fuses, locking off breakers, posting danger signs.

“Danger, Do Not Operate” Sign

Warning notice fixed at the isolation point to deter reconnection while work is in progress.

Calibration Certificate

Document confirming a test instrument has been checked and is giving accurate readings.

Continuity Tester (Ohmmeter)

Instrument used to measure resistance and verify that conductors form an unbroken path.

CPC Sleeving

Green-and-yellow insulation placed over the bare Circuit Protective Conductor before termination.

Pattress

Surface or flush mounting box that houses a socket or switch mechanism.

Spur

Single branch cable taken from a ring final circuit to feed one additional accessory.

Mini-Trunking

Small plastic cable duct used to route and protect surface wiring between accessories.

BS 7671

IET Wiring Regulations setting out requirements for electrical installations in the UK.

Guidance Note 3

IET publication giving detailed advice on inspection and testing procedures under BS 7671.

Minor Electrical Installation Works Certificate

Document confirming that a small addition or alteration has been tested and complies with BS 7671.

Voltage Indicating Device

Generic term for any instrument (tester or multimeter) that shows the presence of voltage.

Multifunction Tester

Combined instrument capable of performing several tests such as continuity, insulation resistance, RCD trip time, etc.

Neutral Conductor (as a Live Conductor)

Return path in an a.c. system; regarded as ‘live’ and must also be isolated during work.

“Electrician at Work” Notice

Temporary label left on site to inform occupants that power is intentionally turned off and provide contact details.