| C |
capacitance [ F, μF] |
| Cmin |
minimim voltage factor ( = 0.95 ) |
| f |
frequency [Hz] |
| Ia |
current causing operation of device in specified time, A |
| In |
nominal current [A] |
| IΔn |
rated current of an RCD, A |
| L |
inductance [ H, mH] |
| R |
resistance [Ω] |
| RA |
sum of resistance of earth electrode and protective condcutor, Ω |
| ULL , or VLL |
line to line voltage [V, kV] |
| ULN or VLN |
line to neutral voltage [V, kV] |
| Uo or Vo |
nominal line to neutral voltage [V, kV] |
| UN or VN |
nominal line to line voltage [V, kV] |
| X |
reactance, general [Ω] |
| Xc |
capacitive reactance [Ω] |
| XL |
inductive reactance [Ω] |
| Z |
impedance [Ω, Ω.m-1] |
| Z1 |
line conductor impedance, Ω |
| Z2 |
circuit protective conductor (CPC) impedance, Ω |
| Ze |
external earth fault impedance, Ω |
| Zs |
earth fault look impedance, Ω |
| ω |
angular frequency = 2πf, s-1 |