Functionality
USER MANUAL FPC 200 - 3/2017 53
Temperature monitoring - ANSI code 38/49T
Temperature monitoring is associated with additional external module including up to 8 resistance temperature detectors
(RTDs). Correct external module connection is required for protection to perform as specified.
2.5.3.1 Functionality
Temperature monitoring is a function, used as
temperature dependent protection. Alarm signal is
stated when measured temperature
exceeds the
selected alarm threshold. Trip signal of function is set
when measured temperature
exceeds the selected trip
threshold. For each RTD there are separate function
settings.
The function operation can be enabled or disabled
individually for each RTD.
38/49T Temp. monitor
COUNTERS
Trip:
Alarm:
220°C
220°C
Alarm:
Trip:
0
0
Enabled: Yes
1 2 3 4 5 6 7 8
Figure 2.33: Temperature monitor setting as seen on HMI.
2.5.3.2 Measurement
Measurement is performed using specific algorithms to
interpret measurement of probes resistance. RTDs are
using 3-wire connection type to temperature sensors.
2.5.3.3 Delay
To ensure correct operation of function an individual
measurement needs to exceed desired threshold of
alarm or trip at least twice in a row.
2.5.3.4 Block of the protection
In addition the individual protection trip exhibits pulse
type if connected to trip relay [4.2.4.5.7, relay mapping
section],
to ensure correct CBFP [2.6.1.10] functionality.
2.5.3.5 RTD fault
RTD fault signal is provided to ensure the correct
operation of external module as well as its sensors. If
the connection to one of the sensors is terminated or
short-circuited, the RTD fault signal is activated. The
signal remains active as long as the fault persists. The
fault can only occur if a protection of a malfunction
sensor is active.
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