ABB 615 Series ANSI, Technical Manual

Page: 585 / 713

Section 8
1MAC050144-MB C
Measurement functions
578 615 series ANSI
Technical Manual
selected to be monitored, the function assumes it to be connected to a voltage measurement
channel. In other words, if an unconnected phase is monitored, the function falsely detects
a voltage interruption in that phase.
The maximum magnitude and depth are defined as percentage values calculated from the
difference between the reference and the measured voltage. For example, a dip to 70
percent means that the minimum voltage dip magnitude variation is 70 percent of the
reference dip voltage amplitude.
The activation of the BLOCK input resets the function and outputs.
8.12.4.3 Duration measurement
The duration of each voltage phase corresponds to the period during which the measured
TRMS values remain above (swell) or below (dip, interruption) the corresponding limit.
Besides the three limit settings for the variation types dip and swell, there is also a specific
duration setting for each limit setting. For interruption, there is only one limit setting
common for the three duration settings. The maximum duration setting is common for all
variation types.
The duration measurement module measures the voltage variation duration of each phase
voltage separately when the Phase mode setting is "Single Phase". The phase variation
durations are independent. However, when the Phase mode setting is "Three Phase",
voltage variation may pick up only when all the monitored phases are active. An example
of variation duration when Phase mode is "Single Phase" can be seen in Figure 311. The
voltage variation in the example is detected as an interruption for the phase B and a dip for
the phase A, and also the variation durations are interpreted as independent V_B and V_A
durations. In case of singlephase interruption, the DIPST output is active when either
PICKUP_A or PICKUP_B is active. The measured variation durations are the times
measured between the activation of the PICKUP_A or PICKUP_B outputs and
deactivation of the PICKUP_A or PICKUP_B outputs. When the Phase mode setting is
"Three Phase", the example case does not result in any activation.
Figure 311: Single-phase interruption for the Phase mode value "Single Phase"
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