App-26
IM 760201-01E
Measurement period
Data update interval
Data update interval
Measurement period
When the
synchronization
source setting is
turned off
Unintended zero crossing caused by pulse noise
Setting the Synchronization Period When Measuring a Three-Phase Device
If a three-phase device is measured with input elements 1 and 2 using a three-phase,
three-wire system, set the synchronization source of input elements 1 and 2 to the same
signal. For example, set the synchronization source of input elements 1 and 2 to U1. The
measurement periods of input elements 1 and 2 will match, and the
Σ
voltage,
Σ
current,
and
Σ
power of a three-phase device can be measured more accurately.
Likewise, if a three-phase device is measured with input elements 1, 2, and 3 using a
three-phase, four-wire system, set the synchronization source of input elements 1, 2, and
3 to the same signal.
To facilitate this sort of configuration, the synchronization source setting on the WT500
is linked to the
Σ
wiring unit of the wiring system (when independent input element
configuration is off). If independent input element configuration (see section 4.2 for
details) is turned on, the synchronization source of each input element in the
Σ
wiring unit
can be set independently.
Measurement period
Data update interval
Synchronization
source
Input signal U1
Input signal U2
Input signal U3
U1 (or I1)
Input element 1
Input element 2
Input element 3
Synchronization Source Setup Example
Appendix 5 Setting the Measurement Period
