VAMP 259 - Page 295

10 Abbreviations and symbols
Technical description
VM259.EN007
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295
PF
Power factor. The absolute value is equal to cos, but the
sign is '+' for inductive i.e. lagging current and '' for
capacitive i.e. leading current.
P
m
Nominal power of the prime mover. (Used by reverse/under
power protection.)
PT
See VT
pu
Per unit. Depending of the context the per unit refers to any
nominal value. For example for overcurrent setting 1 pu =
1xIN.
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
I
L1
Current input for I
L1
I
L2
Current input for I
L2
I
L3
Current input for I
L3
U
L1
Voltage input for U
L1
U
L2
Voltage input for U
L2
U
L3
Voltage input for U
L3
U
Sync
Voltage input for synchronizing voltage. Depending on the
voltage input mode can be phase to ground or phase to phase
voltage
U
L12
Calculated phase to phase voltage U
L12
U
L23
Calculated phase to phase voltage U
L23
U
L31
Calculated phase to phase voltage U
L31
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