Siemens S120 Cooling, Evaluation of the temperature sensors for motor protection

Motor components of the built-in motor and options 3.3 Cooling

3.2.2Evaluation of the temperature sensors for motor protection

Temp–S

Temp–S is used to reliably protect the motor against overheating. If Temp–S responds, then the drive must be quickly shut down in order to prevent the drive converter from continuing to supply current to the stator (= additional thermal load). The current load level setpoint(s), requested from the closed-loop control, causes this thermal load and this can destroy the stator.

Temp-S is evaluated by the SME12x module. The PTC 130°C is used for issuing a warning. If the temperature continues to rise, the PTC 150°C responds when its response temperature is reached at which point the stator must be immediately disconnected from the power supply.

Temp–F

Temp–F supplies an analog signal that is proportional to the temperature and for a symmetrical current load of the three-phase windings provides information about the average motor temperature.

Note

The temperature sensor (Temp–F) only senses the winding temperature between two phases or in one phase in the stator. However, the phases in the synchronous motor are loaded to different degrees depending on the particular operating mode, so that in the worst case, the phases that have not been measured have the higher temperatures.

3.3Cooling

The heat loss generated by the stator winding must be dissipated by a water-cooling system. For this purpose, the machine manufacturer must connect the cooling duct to a cooling circuit in a heat-exchanger unit. For characteristic curves indicating a rise in temperature and drop in pressure of the cooling medium between the inlet and return flow circuit in the cooler as a function of the volume flow rate, see "Technical data and characteristics".

In certain operating statuses (e.g. at high speeds or in S1 mode), the rotor can heat up further due to iron loss. The rated motor torques specified in the data sheets (see "Technical data and characteristics") are valid during operation with water cooling with an inlet temperature of 35 °C and a rotor flange temperature of max. 60 °C. To ensure that these conditions are maintained, additional measures may have to be taken to cool the rotor.

48	1FW6 Built-in torque motors
	Configuration Manual, 05/2009, 6SN1197-0AE00-0BP3