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The non-statutory document that is applicable to the probes and leads of test equipment is:

• HSE Guidance Note GS 38

• BS7671

• The IET On Site Guide

• IET Guidance Note 3.

The following tests may be carried out on a new installation:

1. polarity

2. insulation resistance

3. ring final circuit continuity

4. cpc continuity

• 2,1,4

• 1,2,4,3

• 3,1,2

• 3,2,1.

If the length of a cable is doubled the insulation resistance will be:

• quartered

• halved

• remain the same

• doubled.

If the length of a cable is doubled the resistance will be:

• quartered

• halved

• remain the same

• doubled

When carrying out an initial verification, a check for polarity is carried out when energising of the installation for the first time. This is to confirm:

• correct connection of the incoming supply

• correct connection of equipment

• operation of the main isolator

• operation of the supply fuse.

A continuity of protective conductors test is carried out using a:

• continuity tester

• low reading ohmmeter

• low resistance ohmmeter

• insulation tester.

An increase in conductor operating temperature will result in:

• an decrease in conductor resistance.

• an increase in conductor resistance.

• an increase in insulation resistance.

• no apparent change in resistance or insulation resistance.

The maximum permitted voltage drop for a low voltage lighting circuit supplied directly from the public supply is:

• 2%

• 3%

• 4%

• 5%

External earth fault loop impedance Z_e for an installation must be measured at:

• a convenient point on the installation with the earthing conductor connected.

• a convenient point on the installation with the earthing conductor disconnected.

• the origin of the installation with the earthing conductor connected.

• 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 BS EN 60898 is 0.68Ω. The maximum measured earth fault loop impedance permitted for a circuit protected by this device is

• 0.40Ω

• 0.54Ω

• 0.68Ω

• 0.82Ω