Thermal Motor Protection With Temperature Sensors (Standard Protection) - Siemens SIMOTICS M-1FE1 Configuration Manual

Motor components, characteristics and options
4.1 Motor components
4.1.1.1

Thermal motor protection with temperature sensors (standard protection)

The stator laminated core has 2 Pt1000 temperature sensors to monitor the winding
temperature; one of these is a reserve.
Note
When the motor is operated at its rated power, the winding temperature can reach
approx. 150 °C.
The winding has thermal class 155 (F) and is dimensioned for this operating state.
The type of temperature sensor installed is stamped on the rating plate.
The temperature sensor protects the motor from overload when operational.
The temperature sensor detects the motor temperature. The drive system evaluates the
motor temperature. An external tripping unit is not required. The PTC thermistor function
is monitored.
1. Pre-alarm temperature (default setting for the 1FE1)
If the pre-alarm temperature of 150 °C is exceeded, the drive system issues an
appropriate alarm signal. This alarm signal must be evaluated externally.
The alarm signal is cleared when the motor temperature decreases to below the pre-
alarm temperature.
If the pre-alarm temperature is exceeded for longer than 240 seconds (standard
setting) or longer than the parameterized time, then an alarm signal is issued and the
drive is shut down.
A detailed description is provided in the SINAMICS S120/S150 List Manual.
SINAMICS S120_150 List Manual
(https://support.industry.siemens.com/cs/products?search=Listenhandbuch&dtp=M
anual&mfn=ps&o=DefaultRankingDesc&pnid=13204&lc=de-WW)
2. Motor temperature limit (standard setting for the 1FE1)
If the motor temperature limit of 160 °C ±5 °C is exceeded, the drive system is
shut down and it issues an appropriate fault signal.
Table 4- 1
Resistance when cold (20 °C)
Resistance when hot (100 °C)
Connection
Response temperature (standard setting for
SINAMICS S120)
The resistance change is proportional to the winding temperature change. The
temperature characteristic is taken into account in the closed-loop control.
The following diagram shows the resistance characteristic as a function of the
temperature for Pt1000 temperature sensors.
52
Features and technical data
Type Pt1000
Approx. 1090 Ω
Approx. 1390 Ω
Via signal cable
Pre-alarm at 150 °C
Trip/shutdown at 160 °C ±5 °C
SIMOTICS M-1FE1 synchronous built-in motors
Configuration Manual, 09/2019, A5E47872980B AA