9
Auxiliary measurement
The auxiliary input can be used to monitor a single
phase or symmetrical three phase system. The aux-
iliary input can also be used to monitor the neutral
current of the connected to the main input three
phase system.
In any case the line frequency of the auxiliary sys-
tem must be identical to the line frequency of the
main input, otherwise the measurement error may
be very large.
The auxiliary measurement can be used separately.
The main measurement does not need to be con-
nected in this case. All measured values of the main
input (voltage, current, power, harmonics, transients,
events and flicker) are available for the auxiliary in-
put.
Relevant voltage
All circuits provide the choice of using the line-to-
neutral or line-to-line voltage as the relevant voltage.
Use this setting according to your application needs.
In most cases the relevant voltage for power quality
analysis is L-N in low-voltage distribution and L-L in
medium voltage distribution. The selected relevant
voltage is used for harmonic analysis, transients,
events and flickermeter evalulation. Power measure-
ment always uses L-N voltages and the correspond-
ing currents.
Intendend usage
