Siemens SIMOTICS M-1FE2, Configuration Manual

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Motor components and options
4.1 Motor components
SIMOTICS M-1FE2 built-in motors
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Configuration Manual, 05/2021, A5E50494252B AB
4.1.1.2 Temperature evaluation using the PTC thermistor triplet (full motor protection,
option)
For special applications (e.g. when a load is applied with the motor stationary or for
extremely low speeds), the temperature of all of the three motor phases must be additionally
monitored using a PTC thermistor triplet.
The PTC thermistor triplet must be evaluated using an external tripping/evaluation unit (this is
not included in the scope of delivery). This means that the sensor cable is monitored for wire
breakage and short-circuit by this unit.
The motor must be de-energized within 1 second when the response temperature is
exceeded.
Table 4- 2 Technical data for the PTC thermistor triplet
Designation Technical data
Type (acc. to DIN 44082–M180) PTC thermistor triplet
Thermistor resistance (20° C) ≤ 750 Ω
Resistance when hot (180° C) ≥ 1710 Ω
Connection Via an external trip unit Possible connections
(Page 54)
Cable cross-section/outer diameter 0.14 mm
2
/ 0.9 mm
Response temperature 180° C
Note: PTC thermistors do not have a linear characteristic and are, therefore, not suitable to determine
the instantaneous temperature.
4.1.1.3 Temperature evaluation using NTC thermistors (universal protection, option)
Note
Temperature evaluation using the NTC K227 and NTC PT3-51F thermistors does not
guarantee full motor protection.
NTC K227 and NTC PT3-51F thermistors are used if the drive system cannot evaluate Pt1000
thermistors.
They are intended for operating the motor on third-party systems.
The NTC thermistor should be connected in accordance with the configuration and operating
instructions of the third-party system.