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UMG 509-PRO
www.janitza.com
12.3 Frequency measurement
For the measurement, the device requires the
mains frequency, which can either be specified
by the user or determined automatically by the
device.
·For automatic determination of the frequency,
a voltage (V-Vref) greater than 10 Vrms must be
present on at least one of the voltage measure-
ment inputs.
·The mains frequency must be in the range from
40 Hz to 70 Hz.
·If the measured voltage is not sufficiently high,
the device cannot determine the mains frequen-
cy and therefore cannot carry out a measure-
ment.
12.4 Direction of rotary field
Check the direction of the voltage rotating field in
the measuring display of the device.
Usually it is a "right" rotating field.
UL1-UL2-UL3 = right rotating field
UL1-UL3-UL2 = left rotating field
Fig. Illustration of the phase sequence according to the
direction of the rotating field.
