303 questions

[dragon]

4- A final circuit is installed using single core, PVC insulated, copper cables in steel conduit. The steel conduit is used as the CPC. When an earth fault loop impedance test is carried out the result exceeds the maximum acceptable value of Zs. Describe

a) Three possible faults that may cause the high reading

B) One test that may be applied to locate the fault

5-a) Explain why, in the sequence of tests required by BS7671, the continuity of protective conductors must be completed first.

B) BS7671 requires that a polarity test is made in order to verify three requirements. State each of them

can someone help me please answer this ????

 

[a1]

Hello Dragon,

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Admin.

 

[ADS]

Hi dragon, I'll have a go

4- A final circuit is installed using single core, PVC insulated, copper cables in steel conduit. The steel conduit is used as the CPC. When an earth fault loop impedance test is carried out the result exceeds the maximum acceptable value of Zs. Describea) Three possible faults that may cause the high reading

Most likely will relate to conduit installation - bad connections on joints, bends etc - missing or innappropriate fly leads at CU and junction boxes/ terminations not tight.....that kind of thing

B) One test that may be applied to locate the fault

R2 continuity test with wander lead

5-a) Explain why, in the sequence of tests required by BS7671, the continuity of protective conductors must be completed first.

Question 4A above pretty much answers this

B) BS7671 requires that a polarity test is made in order to verify three requirements. State each of them

Single pole devices connected in line conductor only

Center contact bayonet and edison screw lampholders have outer or screwed contact connected to the neutral conductor

Socket outlets/FCUs etc correctly connected

can someone help me please answer this ????

 

[dragon]

love u x

 

[dragon]

thanks body x