Technical Data; Thermal Overload Protection For Motors Mpttr; Identification; Function Block - ABB RELION REX640 Technical Manual

1MRS759142 C
4.1.8.10
4.1.9
4.1.9.1
4.1.9.2
4.1.9.3
REX640
Technical Manual

Technical data

Table 439: PHPTUC Technical data
Characteristic
Operation accuracy
Start time
Reset time
Reset ratio
Retardation time
Operate time accuracy in definite time mode

Thermal overload protection for motors MPTTR

Identification

Function description
Thermal overload protection for motors

Function block

GUID-5D2D0B94-1683-47A9-85D1-A9B80EBC66B4 V1 EN
Figure 212: Function block

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 drawing excessive current
and overheating, which causes the premature insulation failures of the windings and,
in worst cases, burning out of the motors.
Protection functions
Value
Depending on the frequency of the current
measured: f ±2 Hz
n
±1.5% of the set value or ±0.002 × I
Typically <55 ms
<40 ms
Typically 1.04
<35 ms
mode ±1.0% of the set value or ±20 ms
IEC 61850 IEC 60617
identification identification
MPTTR 3Ith>M
Section 4
n
ANSI/IEEE C37.2
device number
49M
387