1.
What would be the correct procedure to confirm that the existing electrical installation in a dwelling is suitable for the additional wiring of an extension?
2.
What is the purpose of a periodic inspection and test relating to the safety of the building?
3.
What is the minimum level of IP protection for the opening shown as Item A in Figure 1?
4.
What is the minimum level of IP protection for the accessible top surface of a consumer unit?
5.
Which publication gives detailed information for carrying out testing of electrical installations?
6.
What would be agreed with the client and recorded as a limitation for a periodic inspection and test?
7.
Which statutory document includes the requirements for working on live conductors?
8.
What action should the inspector take, both before and after testing, to confirm isolation of the supply?
9.
An inspection is to be carried out at the termination of the circuit conductors inside a terminal box, as shown in Figure 2. Which human sense is best used to confirm the terminals are suitably tightened?
2
10.
An inspection is to be carried out at the termination of the circuit conductors inside a terminal box, as shown in Figure 2. What is confirmed when inspecting the conductor insulation?
11.
An inspection is to be carried out at the termination of the circuit conductors inside a terminal box, as shown in Figure 2. Which classification code would be given on the Schedule of Inspections for the situation shown in Figure 3?
12.
Which classification code indicates that there is a non-compliance which is identified as ‘improvement recommended’?
13.
Which human senses would be best used to determine excess arcing at a contactor during a walk around survey?
14.
A test is to be carried out to confirm the continuity of the main protective bonding conductor to the metallic water installation pipework in a commercial premises. What is the risk if the installation is not safely isolated for this test?
15.
A test is to be carried out to confirm the continuity of the main protective bonding conductor to the metallic water installation pipework in a commercial premises. What is the purpose of the test of continuity of main protective bonding conductors?
16.
A test is to be carried out to confirm the continuity of the main protective bonding conductor to the metallic water installation pipework in a commercial premises. What important check must be made with the instrument leads before a reading is taken?
17.
A test is to be carried out to confirm the continuity of the main protective bonding conductor to the water installation pipework in a commercial premises. Which test method is used for this test?
18.
A 10 mm2 main protective bonding conductor is 37.5 m in length. What is the expected measured resistance when testing the conductor?
19.
What is the most likely cause of the measured value being much higher than the calculated value?
20.
An earth fault loop impedance test is to be carried out on a radial circuit to the local isolator, as shown in figure 4. What must the inspector confirm before the test can be undertaken?
4
21.
An earth fault loop impedance test is to be carried out on a radial circuit to the local isolator, as shown in figure 4. Why can this earth fault loop impedance test be carried out before a test for insulation resistance?
22.
An earth fault loop impedance test is to be carried out on a radial circuit to the local isolator, as shown in figure 4. Why do the test leads used for this test have to comply with GS 38?
23.
An earth fault loop impedance test is to be carried out on a radial circuit to the local isolator, as shown in figure 4. Why would a test to confirm continuity of cpc be unnecessary once the earth fault loop impedance test is completed?
24.
A distribution circuit is protected by a BS 88-3 fuse rated 32 A. What is the maximum acceptable measured earth fault loop impedance for this circuit?
25.
What is confirmed by an earth fault loop impedance test on a radial power circuit?
26.
Voltage drop of a single-phase distribution circuit supplying a power distribution board in a remote building is to be verified as part of the periodic inspection and testing within a workshop complex. The installation forms part of a public 400/230 V TN-S system. The circuit has a measured R1+Rn value of 0.15 Ω and an Ib of 60 A. The circuit protective device has an In of 80 A, see Figure 5. What is the maximum acceptable voltage drop for this distribution circuit if the highest circuit voltage drop on DB-3B is 5.0 V?
5
27.
Voltage drop of a single-phase distribution circuit supplying a power distribution board in a remote building is to be verified as part of the periodic inspection and testing within a workshop complex. The installation forms part of a public 400/230 V TN-S system. The circuit has a measured R1+Rn value of 0.15 Ω and an Ib of 60 A. The circuit protective device has an In of 80 A, see Figure 5. Which are the cable characteristics that affect voltage drop?
28.
Voltage drop of a single-phase distribution circuit supplying a power distribution board in a remote building is to be verified as part of the periodic inspection and testing within a workshop complex. The installation forms part of a public 400/230 V TN-S system. The circuit has a measured R1+Rn value of 0.15 Ω and an Ib of 60 A. The circuit protective device has an In of 80 A. What is the voltage drop for this distribution circuit?
29.
Voltage drop of a single-phase distribution circuit supplying a power distribution board in a remote building is to be verified as part of the periodic inspection and testing within a workshop complex. The installation forms part of a public 400/230 V TN-S system. The circuit has a measured R1+Rn value of 0.15 Ω and an Ib of 60 A. The circuit protective device has an In of 80 A, see Figure 5. Why is the test to confirm voltage drop carried out?
30.
Testing of the RCDs is to be undertaken on the installation which forms part of a TT system, as shown in Figure 6. What is confirmed by testing the 100 mA RCD?
31.
Testing of the RCDs is to be undertaken on the installation which forms part of a TT system, as shown in Figure 6. What must be agreed with the users of the installation before the test of the 100 mA RCD can be carried out?
32.
Testing of the RCDs is to be undertaken on the installation which forms part of a TT system, as shown in Figure 6. What is the maximum test current to be applied by the RCD tester, when verifying that the RCD at the origin meets disconnection times?
33.
Testing of the RCDs is to be undertaken on the installation which forms part of a TT system, as shown in Figure 6. When testing the 30 mA RCD at 5 x I∆n the RCD did not operate because the 100 mA RCD at the origin of the installation tripped out. What is the most likely reason for this RCD tripping?
34.
Testing of the RCDs is to be undertaken on the installation which forms part of a TT system, as shown in Figure 6. When testing the 30 mA RCD at I∆n a disconnection time of 400 ms is recorded. What classification code should the inspector record on the report?
35.
What is the maximum disconnection time for a 16 A final circuit on a TT installation?
36.
What is the purpose of carrying out a test to determine the prospective fault current at the origin of a three-phase commercial installation?
37.
The radial circuit, shown in Figure 7, is installed using-single core cables in PVC conduit. The installation is 5 years old and there have been no alterations or additions to the radial circuit.
38.
Insulation resistance testing has been carried out on a six-way lighting distribution board and the individual circuit results are shown in Table 1. What is the value of insulation resistance between Live and Earth for the DB with all the lighting circuits connected?
39.
What is the most appropriate classification code to be recorded if the insulation resistance for a circuit is measured at 0.90 MΩ between live conductors and Earth?
40.
A test is to be carried out to determine the external earth fault loop impedance of an installation forming part of a TN-S system. What is the maximum declared by the Distribution Network Operator for a TN-S supply?
