Inspection and testing live tests

Which of the following is the direct departure from BS7671 when a measured value of Ipf considerably exceeds those permitted for the protective devices installed at the point of test?

• Earth fault disconnection times will be exceeded

• Devices will safely interrupt the fault in time

• Devices will not safely interrupt the fault in time

•       Disconnection times will be exceeded

What is the maximum permitted disconnection time for 100ma RCD to BSEN 61008 in order to meet specified time/current performance, when tested at 1xI n?

• 40ms

• 100ms

• 200ms

• 300ms

Which one of the following is used to establish phase sequencing for an installation

• Frequency meter

• Power factor indicator

• Rotating disc instrument

• Earth fault loop impedance tester

Which one of the following is the range tests that are carried out for RCD’s

• ½ x I△n  – 150 x I△n

• ½ x I△n –1 x I△n

• ½ x I△n  – 2 x I△n – 150 x I△n   

• ½ x I△n  – 2 x I△n – 5 x I△n 

Functional tests are to be carried out on a general purpose RCD using a RCD tester. At which point during the testing process would the effectiveness of the test button on the RCD be checked.

• Before the instrument test

• Following all instrument tests

• Following the 0.5 X I n test but before the 1 x I△n test

• At no point as the instrument tests will carry out these functions

The current measured between line and neutral at the origin of an electrical installation forming part of a TT system would be recorded as the

• Design current

• Nominal Current

• Rated current

• Prospective fault current

The relationship between the maximum measured (Ipf) and the breaking capacity of any protective device is that the device breaking capacity is

• Greater than the measured Ipf

• Lower than the measured Ipf

• Lower for ring circuits

• Lower for radial circuits

Which of the following values is recorded when verifying Ipf for a single phase circuit

• The lowest value from PSCC and PEFC

• PSCC multiplied by a factor of 2

• PSCC added to PEFC

• The higher value from PEFC and PSCC

Which of the following is the correct method of measurement for PSCC for a single phase installation using two leads

• Using a test instrument on pfc scale between line intake and main earthing terminal

• Using a test instrument on pfc scale between neutral intake and main earthing terminal

• Using a test instrument on pfc scale between main intake line and neutral

• Using a test instrument on ohms scale between main intake line and neutral

Which of the following is the correct method of measurement for PEFC for a single phase installation using two leads

• Using a test instrument on pfc scale between line intake and main earthing terminal

• Using a test instrument on pfc scale between neutral intake and main earthing terminal

• Using a test instrument on pfc scale between main intake line and neutral

• Using a test instrument on ohms scale between main intake line and neutral