Operation Manual

GMC-I Messtechnik GmbH 13

Reactive power measurement on three-wire, three-phase systems of balanced

load

It is easy to determine the reactive power on three-wire, three-phase

systems of balanced load. Set the function switch to the " " posi-

tion. To obtain the reactive power, multiply the found value (pointer

deflection x scale factor) by the factor of .

With a connection according to the following wiring diagram and a

positive indication, the measured reactive power is inductive. With a

negative pointer deflection, the measured reactive power is capacitive.

To obtain a positive indication, transpose the connection L1 and L2 on

the meter

(cond. L2 to connector L2 (5) and cond. L3 to connector L1 (2)).

4.3 Measured results

To determine the measured active power, it is merely required to mul-

tiply the pointer deflection with the constant c, and eventually with

the transformer ratios. In any case, it applies:

(2)

(5)

(8)

(3)

(1)

Direct connection:

Q (var) = · I · U · sin 

= · · c

P (W) = · c · ü

· ü