List of Abbreviations
A ampere - unit of electric current
BC bayonet cap
Ca ambient temperature correction factor
CENELEC European Committee for Electrotechnical Standardisation
Cg cable grouping correction factor
Ci thermal insulation correction factor
Ct correction factor for the conductor operating temperature
CNE combined neutral and earth
cos 0 power factor (sinusoidal systems)
CPC circuit protective conductor
c.s.a cross-sectional area
De overall cable diameter
ECA  Electrical Contractors Association
EEBAD earthed equipotential bonding & automatic disconnection
ELCB earth leakage circuit breaker
ELV  extra-low voltage
EMC electro-magnetic compatibility
e.m.f. electro-motive force
EMI electro-magnetic interference
ES edison screw
f frequency
FELV functional extra-low voltage
GN guidance note
HBC high breaking capacity (fuse)
HRC high rupturing capacity (fuse)
Hz Hertz - unit of frequency
I  symbol for electric current
I2 operating current (fuse or circuit breaker)
Ia  current to operate protective device
Ib design current
Id fault current
IEC International Electrotechnical Commission
IEE Institution of Electrical Engineers
In  current setting of protective device
It tabulated current
Iz current carrying capacity
IT  earthing system (see 5.2.6)
k kilo - one thousand times
kV kilovolt (1000 V)
L1,L2,L3 lines of three-phase system
m metre
m milli - one thousandth part of
M meg or mega - one million times
mA milliampere
MCB miniature circuit breaker
MCCB  moulded case circuit breaker
MD maximum demand
m.i. mineral-insulated
NICEIC National Inspection Council for Electrical Installation Contracting
p.d. potential difference
PELV protective extra-low voltage
PEN combined protective and neutral
PME protective multiple earthing
PIR passive infra-red detector
PSC prospective short-circuit current
p.v.c.  poly-vinyl chloride
R resistance (electrical)
R resistance of supplementary bonding conductor
Ra the total resistance of the earth electrode and the protective conductor onnecting it to exposed conductive parts
Rp resistance of the human body
RCCB residual current circuit breaker
RCD residual current device
r.m.s. root-mean-square (effective value)
s second - unit of time
S conductor cross-sectional area
SELV seperated extra-low voltage
t time
TN-C earthing system (see 5.2.5)
TN-C-S earthing system (see 5.2.4)
TN-S earthing system (see 5.2.3)
TT earthing system (see 5.2.2)
U symbol for voltage (alternative for V)
Uac alternating voltage
Udc  direct voltage
Uo phase voltage
V volt - unit of e.m.f. or p.d.
W watt - unit of power
X reactance
Z impedance (electrical)
Ze earth loop impedance external to installation
Zs earth fault loop impedance
0 phase angle
   
   

Extracted from The Electricians Guide Fifth Edition
by John Whitfield

Published by EPA Press
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Click here for list of abbreviations