BS7671:2018 Electrical Regulations revision 2 - Based on C&G2382
Electrical Regulations (based on C&G2382). YOU NEED A COPY OF BS7671:2018 FOR THIS EXERCISE. 12 randomised questions from a LARGE question bank.
Answer ALL questions in the exercise. Look for any feedback given when you answer. If you get an answer incorrect - keep trying until you get the correct answer. A score is given when ALL questions have been answered correctly. © K.Brown (2018)
BS7671 is regarded as a .....
- document exclusive to electricians
- legal document
- non-statutory document
- statutory document
BS7671 states that persons and all livestock shall be protected against injury that results from an overvoltage originating from...
- equipment that is on and running
- the opertion of mcb's
- atmospheric events
- voltage generation
BS7671 states that the protection against voltage disturbances shall have adequate levels of immunity against...
- weather
- electromagnetic disturbance
- loss of voltage
- vibrations
Identify the maximum Zs (tabulated) value for a 10A 'C'-type mcb
- 1.15 ohms
- 2.19 ohms
- 1.44 ohms
- 1.92 ohms
A double-insulated appliance is defined as....
- class I equipment
- class II equipment
- class V equipment
- ELV equipment
An electrical installation certificate must only be signed by..
- the REC
- the local authority
- a competent person
- the customer
External Influence code 'AD4' requires equipment to be protected to..
- IPx0
- IPx1
- IPx4
- IPx5
External Influence code 'AD1' requires equipment to be protected to..
- IPx2
- IPx1
- IPx0
- IPx5
When refering to external influences, code AA5 relates to
- ambient temp range -5 to +35 degreesC
- ambient temp range -65 to +5 degreesC
- ambient temp range +5 to +40 degreesC
- ambient temp range -15 to +5 degreesC
When refering to external influences, code AA1 relates to
- ambient temp range -5 to +35 degreesC
- ambient temp range -65 to +5 degreesC
- ambient temp range -60 to +5 degreesC
- ambient temp range -15 to +5 degreesC
BS7671 states that 'electrical installations are arranged into circuits to....'
- allow easier access to the electrical installation
- allow higher distribution of power to the circuits
- allow for easu expansion without affecting total loading
- reduce electromagnetic interference
a Ze value for an electrical installation can be found be taking a measurement at the...
- at the end of a circuit in the installation
- at the furthest socket outlet
- at the origin of the installation
- furthest point in the installation
Identify the maximum disconnection time for a 230v AC fixed equipment circuit not exceeding 32A, as part of a TN system.
- 2 secs
- 0.4 secs
- 40mS
- 5 secs
Identify the maximum tabulated Zs value for a 16A type 'B' mcb
- 1.87 ohms
- 0.87 ohms
- 2.42 ohms
- 2.73 ohms
undervoltage protection is required when the restoration of an electrical supply to an item of equipment following a power-cut could lead to.....
- accidental operation of RCD's
- unexpected stalling of a motor
- circuit overload
- unexpected starting-up of motors
a device which disconnects all or part of an installation from every source of supply is known as..
- emergency switching
- isolation
- firemans switch
- functional switching
For a 32A B-type mcb protecting an A1 ring circuit, the maximum (tabulated) Zs value allowed is..
- 0.72 ohms
- 0.35 ohms
- 1.37 ohms
- 2.96 ohms
In a TT installation, distribution circuits must disconnect within
- 0.4 secs
- 5 secs
- 1 sec
- 0.2 secs
a RCD operates on which one of the following principles
- magnetic operation caused by an imbalance between line and neutral
- thermal operation of a bi-metallic strip
- magnetic solenoid action caused by a short circuit between line and neutral
- thermal operation caused by the fault current
a RCBO can protect against..
- short circuit faults
- short circuit and earth faults
- short circuit and overload faults
- overload faults
Nuisance tripping caused by large inductive loads starting-up can be reduced by using..
- RCD
- RCBO
- type C mcb
- type D mcb
in AC circuits, if basic protection were to fail, additional protection could be provided by
- extra bonding
- 30mA rcd
- electrical separation
- using a low voltage supply