ABB Relion Technical Manual page 534

Section 14
Monitoring
528
clamping might be overridden by the zero point clamping used for the measurement
values within CVMMXN.
Continuous monitoring of the measured quantity
Users can continuously monitor the measured quantity available in each function block by
means of four defined operating thresholds, see figure 241. The monitoring has two
different modes of operating:
• Overfunction, when the measured current exceeds the High limit (XHiLim) or High-
high limit (XHiHiLim) pre-set values
• Underfunction, when the measured current decreases under the Low limit (XLowLim)
or Low-low limit (XLowLowLim) pre-set values.
X_RANGE is illustrated in figure 241.
Y
High-high limit
High limit
X_RANGE=0
Low limit
X_RANGE=2
Low-low limit
X_RANGE=4
IEC05000657 V1 EN
Figure 241: Presentation of operating limits
Each analog output has one corresponding supervision level output (X_RANGE). The
output signal is an integer in the interval 0-4 (0: Normal, 1: High limit exceeded, 3: High-
high limit exceeded, 2: below Low limit and 4: below Low-low limit). The output may be
connected to a measurement expander block (XP (RANGE_XP)) to get measurement
supervision as binary signals.
The logical value of the functional output signals changes according to figure 241.
The user can set the hysteresis (XLimHyst), which determines the difference between the
operating and reset value at each operating point, in wide range for each measuring
channel separately. The hysteresis is common for all operating values within one channel.
X_RANGE = 3
X_RANGE= 1
Hysteresis
X_RANGE=0
1MRK 502 048-UUS A
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en05000657.vsd
Technical manual