Deck 9: Electrical-Installations

Question 1

Where BS 7671 show a protective device as having a maximum Zs value of 2.3O the maximum corrected value will be

A) 2.3Ω
B) 1.84Ω
C) 1.72Ω
D) 2.87Ω

Answer 1

B

Question 2

The maximum tabulated Zs for a protective device as shown in BS 7671 is 1.44Ω, the maximum permissible measured Zs will be

A) 1.44Ω
B) 1.43Ω
C) 1.15Ω
D) 1.08Ω

Answer 2

C

Question 3

The stated maximum Ze for a TN-S supply system is

A) 0.35Ω
B) 0.21Ω
C) 0.8Ω
D) 0.85Ω

Answer 3

C