Earthing Conductors and Protection - use BS7671:2018 Amendment 2:2022
Earthing Conductors and protection - bonding types, terms, labels, connections, types of earth conductor, exposed and extraneous conductive parts, methods of fault and basic protection - 12 questions from a bank of questions
Which term best describes 'bonding' with reference to protection?
linking together exposed or extraneous conductive parts
connecting to the general mass of earth
linking exposed conductive parts to the main earthing terminal
connecting the exposed conductive parts of equipment to the earthing conductor
Which term best describes 'earthing' with reference to protection?
linking together exposed or extraneous conductive parts
connecting to the general mass of earth
linking exposed and extraneous conductive parts to the main earthing terminal
connecting the exposed conductive parts of equipment to the earthing conductor
What voltage value is given for the 'general mass of earth'?
230 volts
zero volts
1 volt
400 volts
Which one of the following is an 'exposed conductive part'?
copper water pipe
stainless-steel sink
metal-clad grid-switch
steel gas pipe
Which one of the following is an 'exposed conductive part'?
structural steel girder
aluminium window frame
steel trunking
mild-steel steam pipe
Which one of the following is an 'extraneous conductive part'?
metal grill on an electric heater
metallic pump housing
structural steelwork
metal-clad fuse board
Which one of the following is an 'extraneous conductive part'?
electric fan heater
washing machine chassis
aluminium door frame
metal-clad 13A double socket outlet
Which one of the following provides 'fault protection'?
use of double-insulated (CLASS II) equipment
electrical separation (i.e. via transformer)
placing live conductors out of reach
Earthing and Bonding
Which one of the following provides 'fault protection'?
use of double-insulated CLASS II equipment
insulation on conductors
use of barriers and enclosures
ADS
Which one of the following provides 'basic protection'?
use of double-insulated CLASS I equipment
earthing and bonding
fuses and circuit breakers
insulation on conductors
Which one of the following provides 'basic protection'?
Automatic Disconnection of the Supply (ADS)
earthing and bonding
fuses and circuit breakers
use of barriers and enclosures
What term is given to 'double insulated' equipment?
CLASS I
CLASS II
CLASS V
CLASS Z
What term is given to equipment with exposed, earthed metalwork?
CLASS II
CLASS I
CLASS V
CLASS Z
What name is given to the earth conductor that connects exposed metalwork in circuits/equipment to the Main earthing Terminal (MET) of the installation?
c.p.c
main earthing conductor
supplementary bonding conductor
main equipotential bonding conductor
What name is given to the earth conductor that connects the Main earthing Terminal (MET) of the installation to the Earthing facility from the Electricity Supply Company?
c.p.c
main earthing conductor
supplementary bonding conductor
main equipotential bonding conductor
What name is given to the earth conductor that connects between extraneous conductive parts (i.e. hot and cold copper water pipes under a bath)?
c.p.c
main earthing conductor
supplementary bonding conductor
main equipotential bonding conductor
What name is given to the earth conductor that connects an extraneous conductive part to the Main Earthing Terminal (MET) of an installation (i.e. metallic gas supply pipe near the gas meter)?
c.p.c
main earthing conductor
supplementary bonding conductor
main equipotential bonding conductor
Within what distance from the outlet of a gas meter MUST a bonding connection be made?
within 60mm
within 100mm
within 600mm
within 1000mm
What is the exact wording on a BS951 earthing/bonding clamp?
danger - do not remove
warning - electrical safety connection
electrical safety connection - do not remove
safety electrical connection - do not remove
With reference to RCD protection, calculate the maximum theoretical Earth Fault Loop Impedance value for a 30mA device supplied at 230v AC.
1667 ohms
500 ohms
167 ohms
100 ohms
With reference to RCD protection, calculate the maximum theoretical Earth Fault Loop Impedance value for a 100mA device supplied at 230v AC.
500 ohms
1667 ohms
167 ohms
100 ohms
With reference to RCD protection, calculate the maximum theoretical Earth Fault Loop Impedance value for a 500mA device supplied at 230v AC.
100 ohms
1667 ohms
167 ohms
500 ohms
With reference to RCD protection, state the maximum Earth Fault Loop Impedance that must not be exceeded for 30 and 100mA devices supplied at 230v AC.