List of Abbreviations
| A | ampere - unit of electric current |
| BC | bayonet cap |
| Ca | ambient temperature correction factor |
| CENELEC | European Committee for Electrotechnical |
| Cg | cable grouping correction factor |
| Ci | thermal insulation correction factor |
| Ct | correction factor for the conductor |
| 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 & |
| 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 |
| Ia | current to operate protective device |
| Ib | design current |
| Id | fault current |
| IEC | International Electrotechnical |
| 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 |
| 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 |
| Ra | the total resistance of the earth electrode |
| 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 |
| Zs | earth fault loop impedance |
| 0 | phase angle |
Extracted from The Electricians Guide Fifth Edition
by John Whitfield
Published by EPA Press Click Here to order your Copy.