Part P Testing and Inspection

Question 1

According to BS 7671, what is the correct sequence of tests for initial verification of an electrical installation?

Accepted Answer

Continuity of protective conductors, continuity of ring final circuits, insulation resistance, polarity, earth fault loop impedance, RCD operation

Answer

Insulation resistance, continuity, polarity, earth fault loop impedance, RCD

Answer

RCD operation first, then all other tests in any order

Answer

Earth fault loop impedance, RCD, continuity, insulation resistance

Question 2

When testing the continuity of a ring final circuit, what is the expected result at the socket furthest from the consumer unit?

Accepted Answer

Approximately 25% of the end-to-end resistance (r1 + r2)/4

Answer

Zero ohms

Answer

The full end-to-end resistance

Answer

Open circuit

Question 3

What test voltage is applied when performing an insulation resistance test on a 230V circuit?

Accepted Answer

500V DC

Answer

230V AC

Answer

250V DC

Answer

1000V DC

Question 4

During an earth fault loop impedance test, the measured Zs value at a 32A Type B MCB protected socket is 1.20Ω. Is this satisfactory?

Accepted Answer

No — the measured value must not exceed 80% of the tabulated value (1.15Ω) to allow for temperature increase

Answer

Yes — it is below the tabulated maximum of 1.44Ω

Answer

No — the value should be below 0.5Ω for all circuits

Answer

Yes — any value below 2Ω is acceptable

Question 5

What is the purpose of a prospective fault current (PFC) measurement during initial verification?

Accepted Answer

To verify that the breaking capacity of the installed protective devices is adequate to safely interrupt the fault current

Answer

To determine the size of cable needed

Answer

To calculate the electricity bill

Answer

To test the insulation quality

Question 6

Which certificate must be issued upon completion of a new domestic electrical installation?

Accepted Answer

Electrical Installation Certificate (EIC) with a schedule of inspections and schedule of test results

Answer

Minor Electrical Installation Works Certificate

Answer

Periodic Inspection Report

Answer

PAT test certificate