VAMP 52 - Page 226

10 Abbreviations and symbols Technical description
226
VAMP 24h support phone +358 (0)20 753 3264 VM50.EN004
pu
Per unit. Depending of the context the per unit refers to any
nominal value. For example for overcurrent setting 1 pu =
1xI
mode
.
Q Reactive power. Unit = [var] acc. IEC
RMS Root mean square
S Apparent power. Unit = [VA]
SNTP Simple Network Time Protocol for LAN and WWW
TCS Trip circuit supervision
THD Total harmonic distortion
U
0sec
Voltage at input U
c
at zero ohm earth fault. (Used in voltage
measurement mode "2LL+Uo")
U
a
Voltage input for U
12
or U
L1
depending of the voltage
measurement mode
U
b
Voltage input for U
23
or U
L2
depending of the voltage
measurement mode
U
c
Voltage input for U
31
or U
0
depending of the voltage
measurement mode
U
n
Nominal voltage. Rating of VT primary or secondary
UTC
Coordinated Universal Time (used to be called GMT =
Greenwich Mean Time)
VT Voltage transformer i.e. potential transformer PT
VT
pri
Nominal primary value of voltage transformer
VT
sec
Nominal secondary value of voltage transformer
WWW
World wide web  internet