Siemens SIMOTICS T-1FW6 - Page 53

In addition, 1FW6090-xxxxx-xxx2 to 1FW6290-xxxxx-xxx2 motors are equipped with the
following temperature monitoring circuit:
• 1 x PTC 150 °C temperature sensor for each phase winding U, V and W, response threshold
at 150°C
The three PTC temperature sensors (PTC thermistor temperature sensors) of this temperature
monitoring circuit are connected in series with a PTC triplet.
37&
Figure3-10 PTC triplet
To protect the power connection at the enclosure against thermal overload, an additional
PTC 80 °C is connected in series with the PTC 130 °C triplet. For stators of 1FW6090-xxxxx-xxx2
to 1FW6290-xxxxx-xxx2, an additional PTC80°C is connected in series with the PTC150°C
triplet.
Every phase winding is monitored so that also uneven currents - and therefore the associated
di󹪜erent thermal loads of the individual phase windings - are detected. For the following motion
and/or operating states, the individual phase windings have di󹪜erent thermal loads, while the
motor simultaneously outputs a torque:
• At standstill (holding)
• When rotating very slowly
• Oscillation through a very small angle
Note
Shutdown time
If Temp‑S responds, and its response threshold is not undershot again in the meantime, then the
drive system must shut down (de-energize) the motor within 2 seconds. This prevents the motor
windings from becoming inadmissibly hot.
NOTICE
Motor destroyed as a result of overtemperature
The motor can be destroyed if the motor winding overheats.
• Connect Temp‑S.
• Evaluate Temp‑S.
• Ensure that the shutdown time is not exceeded.
Description
3.4Design
1FW6 built-in torque motors
Operating Instructions, 09/2022, A5E52220812B AA 51