INDEX

A

Alarms, see under Security Approved test lamps , 55

B

Basic protection , 103 Block diagrams , 5 BS EN 60617 symbols , 1–4

C

Cable fault location , 89 Call systems , 40 , 92 Care of instruments , 56 Central heating systems , 46 , 93 Circuit convention , 9 Circuit diagrams , 6 Closed-circuit system , 37 Continuity: of protective conductors , 57 of ring circuit conductors , 61

D

Diagrams , 1 Direct-on-line starter , 42 Distribution systems , 26 , 28–29

E

Earth , 104 Earth electrode resistance , 74 Earth fault loop impedance , 70 Emergency lighting , 32 , 91 Extra low-voltage lighting , 49

F

Fault fi nding , 85 Fault protection , 103 Fire alarm system , 36 , 92 Functional testing , 79

I

Insulation resistance , 66 Interconnection diagram , 5 Ladder logic , 17–20

M

Maintained system , 32 Motor starter circuits , 42 , 94 Murray loop test , 89

N

Non-maintained system , 32 Normally closed and open contacts , 9

O

Open-circuit system , 36 Overload current , 86

P

Polarity , 69 Programmable logic controllers , 17 Prospective short circuit current ,74

R

Radial systems , 24 Residual current devices , 80 RCD testing , 79 Relay logic , 15 Ring fi nal circuits , 26

S

Safe isolation , 107 Security systems , 36 , 92 Selecting test instruments , 54 Shock risk , 101 Short-circuit current , 83 , 86 Star-delta starter , 43

T

Tamper loop , 39 Telephone system , 51 Testing , 53

W

Wiring diagram , 6 Wiring systems , 23