HT instruments SIRIUS89N - Manual (Page 128)

SIRIUS89N
EN - 126
16.12.2. 3 Phase 3 Wire System
In the electrical systems distributed without neutral, the phase voltages and the power
factors and phase cos
ϕ lose importance. Only the phase to phase voltages, the phase
currents and the total powers remain defined.
Phase 1
Phase 2
Phase 3
W 1-2
VAR 1-2
W 3-2 VAR 3-2
Three-phase
equipment
In this case the potential of one of the three phases (for example, phase 2) is taken on as
reference potential. The total values of the active, reactive and apparent power are
expressed as sum of the indications of the couples of Wattmeters, VARmeters and
VAmeters.
( ) ( )
2
2 3 2 1
2
2 3 2 1
2 3 2 1
2 3 2 1
− − − −
− −
− −
+ + + =
+ =
+ =
VAR VAR W W S
VAR VAR Q
W W P
TOT
TOT
TOT