022 Online Part 4

(411.1) Protection by automatic disconnection of supply is

• Permitted only if the installation is under effective supervision

• A method of reducing magnetic effects

• A combination of basic and fault protection

• A combination of thermal and overvoltage protection

(411.3.2.2) The maximum disconnection time for a 230 V AC, 50 A circuit incorporating a socket-outlet in a TN system is

• 0.2 seconds

• 0.4 seconds

• 1 second

• 5 seconds

(41.1) When calculating earth fault loop impedance, U0 represents the

• Design Current

• Nominal line voltage to earth

• Prospective short circuit current

• Open circuit voltage of the supply transformer

(41.3) A 6 A BS EN 61009 RCBO with a maximum value of earth fault loop impedance of 1.82 Ω is

• Type A

• Type B

• Type C

• Type D

(411.8.3) The maximum disconnection time for a circuit supplied by a reduced low voltage system using a 110 V midpoint earthed transformer is

• 0.2 seconds

• 0.4 seconds

• 1 second

• 5 seconds

(415.1.1) Where basic protection and/or fault protection is provided, certain external influences may require additional protection provided by

• Obstacles

• Placing out of reach

• The use of RCD’s ≤ 30 mA

• The use of time delayed 100 mA RCDs

(416.2.2) The horizontal top surface of a barrier or enclosure which is readily accessible shall provide a degree of protection of at least

• IP55 or IP66

• IPX4 or IPXX7

• IPXXB or IP2X

• IPXXD or IP4X

(415.1.1) Additional protection against shock is provided by

• BS 3036 fuses

• BS EN 60898 circuit breakers

• Time delayed 100 mA RCDs

• RCDs ≤ 30 mA

(421.1.7) An Arc Fault Detection Device shall conform to which standard

• BS EN 62060

• BS EN 60898

• BS EN 62606

• BS EN 66206

(445.1.5) An undervoltage device has operated and restoring the supply may cause danger. The reclosure of this device should be

• Automatic when under the supervision of a competent person

• Manually operated

• Restored after a set time automatically

• Automatic with time delay