Testing And Inspection Revision Flashcards
(20 cards)
Non-statutory document that is applicable to the probesand leads of test equipment
Hse guidance note Gs 38
The following tests may be carried out on a new installation: 1- polarity 2- insulation resistance 3- ring final circuit continuity 4- cpc continuity, what is the correct sequence for a new ring final circuit
3, 2,1- ring final circuit continuity, insulation resistance, polarity
If the length of a cable is doubled the insulation resister will be
Halved
If the length of a cable is doubled the resistance will be
Doubled
When carrying out an initial verification, a check for polarity is carried out when energising the installation for the first time, why is this?
Correct connection of the incoming supply
A continuity of protective conductors test is carried out using a
Low resistance ohmmeter
The maximum permitted voltage drop for a low voltage lashing circuit supplied directly from the public supply is
3%, 3% is for lighting and 5% is for power
An increase in conductor operating temperature will result m
An increase in conductor resistance
External earth fault loop impedance Ze for an installation must be measured at
The origin of the installation with the earthing conductor disconnected
The maximum tabulated earth fault loop impedance value for a 32a type c circuit breaker to Bsen 60898 is 0.68, the maximum measured earth fault loop impedance permitted for a circuit protected by this device is
0.54 because 0.68 ÷ 100 = 0.0068 then x 80 =0.54 - the rue of thumb
Following the installation and completion of a new circuit the following should be issued
Eic, electrical installation certificate
Rcd testers display the test result in what
Milliseconds
An approved voltage indicator should have test leads fused at what
0.5a
A 30 ma Rcd utilised for additional protection when rested of 150 ma should operate within
40ms
The top surface of switch gear giving ip 4x protection would be checked with wire of csa
1 mm
The minimum acceptable value for an installation resistance test on a selv circuit is
1M ohm
A 32a 60898 circuit breaker protects a ring final circuit the Max result allowing the 0.8 factor should be
1.09 ohms
The open circuit resistance values on a ring final circuit were r1= 0.6, rn= 0.6 and r2= 0.96 what would be the r1 + r2 value expected for the circuit
0.39 ohms, because 0.6+ 0.96 ÷4= 0.39
A test on 6 circuits reveals a test result of 1.6Mohms, what as the inspector and tester would you do
Consider dividing the installation and retest
A circuit under test has a link between line and cpc at one end with a low resistance ohm meter connected between the same conductors at the other end, the test could indicate
Continuity and r1+ r2 values
