ABB REF615 F - Technical Data; Identification; Function Block

4.1.8.9 Technical data
Table 255: LOFLPTUC Technical data
Characteristic Value
Operation accuracy Depending on the frequency of the current
measured: f
n
±2 Hz
±1.5% of the set value or ±0.002 x I
n
Start time Typical 300 ms
Reset time < 40 ms
Reset ratio Typical 1.04
Retardation time < 35 ms
Operate time accuracy in definite time mode ±1.0% of the set value or ±20 ms
4.1.9 Thermal overload protection for motors MPTTR
4.1.9.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Thermal overload protection for motors MPTTR 3Ith>M 49M
4.1.9.2 Function block
GUID-1EEED1E9-3A6F-4EF3-BDCC-990E648E2E72 V4 EN
Figure 124: Function block
4.1.9.3 Functionality
The thermal overload protection for motors function MPTTR protects the electric
motors from overheating. MPTTR models the thermal behavior of motor on the
basis of the measured load current and disconnects the motor when the thermal
content reaches 100 percent. The thermal overload conditions are the most often
encountered abnormal conditions in industrial motor applications. The thermal
overload conditions are typically the result of an abnormal rise in the motor
running current, which produces an increase in the thermal dissipation of the motor
and temperature or reduces cooling. MPTTR prevents an electric motor from
1YHT530004D05 D Section 4
Protection functions
615 series 247
Technical Manual