Blocking logic
There are three operation modes in the blocking function. The operation modes are
controlled by the BLOCK input and the global setting in Configuration/System/
Blocking mode which selects the blocking mode. The BLOCK input can be controlled
by a binary input, a horizontal communication input or an internal signal of the
protection relay's program. The influence of the BLOCK signal activation is
preselected with the global setting Blocking mode.
The Blocking mode setting has three blocking methods. In the "Freeze timers" mode,
the operation timer is frozen to the prevailing value, but the OPERATE output is not
deactivated when blocking is activated. In the "Block all" mode, the whole function is
blocked and the timers are reset. In the "Block OPERATE output" mode, the function
operates normally but the OPERATE output is not activated.
4.7.5 Application
The function block can be used for any general analog signal protection, either
underprotection or overprotection. The setting range is wide, allowing various
protection schemes for the function. Thus, the absolute hysteresis can be set to a value
that suits the application.
The temperature protection using the RTD sensors can be done using the function
block. The measured temperature can be fed from the RTD sensor to the function input
that detects too high temperatures in the motor bearings or windings, for example.
When the ENA_ADD input is enabled, the threshold value of the internal comparator
is the sum of the Start value Add and Start value settings. This allows a temporal
increase or decrease of the level detector depending on the sign and value of the Start
value Add setting, for example, when the emergency start is activated. If, for example,
Start value is 100, Start value Add is 20 and the ENA_ADD input is active, the input
signal needs to rise above 120 before MAPGAPC operates.
4.7.6 Signals
Table 484: MAPGAPC Input signals
Name
Type Default Description
AI_VALUE FLOAT32 0.0 Analogue input value
BLOCK BOOLEAN 0=False Block signal for activating the blocking mode
ENA_ADD BOOLEAN 0=False Enable start added
Table 485: MAPGAPC Output signals
Name
Type Description
OPERATE BOOLEAN Operate
START BOOLEAN Start
1MRS758755 A Section 4
Protection functions
REC615 and RER615 459
Technical Manual
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