ABB REO 517, Applications Manual, Page: 349 / 440

339
Monitoring of AC analog measurements
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The accuracy of measurement depends on the requirements. Basic accuracy satisfies the
operating (information) needs. An additional calibration of measuring channels is nec-
essary and must be ordered separately when the requirements on accuracy of the mea-
surement are higher. Refer to the technical data and ordering particulars for the
particular terminal.
The information on measured quantities is then available for the user at different loca-
tions:
• Locally by means of the local human-machine interface (HMI) unit.
• Locally by means of a front-connected personal computer (PC).
• Remotely over the LON bus to the station control system (SCS)
• Remotely over the SPA port to the station monitoring system (SMS).
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Each measuring channel has an independent measuring range from the others. This al-
lows the users to select the most suitable measuring range for each measuring quantity
on each monitored object of the power system. This gives a possibility to optimize the
functionality of the power system.
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Users can continuously monitor the measured quantity in each channel by means of four
built-in operating thresholds (figure 182). The monitoring has two different modes of
operating:
• Overfunction, when the measured current exceeds the HiWarn or HiAlarm pre-set
values.
• Underfunction, when the measured current decreases under the LowWarn or Low-
Alarm pre-set values.