HT instruments SIRIUS89N User Manual

Page 128

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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



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