With An Fso Module - ABB ACS880 Series User Manual

20 ATEX-certified motor thermal protection function with PTC thermistor relays (+L513+Q971)

With an FSO module

1. When the motor temperature rises to the thermistor wake-up level, the resistance of
the thermistor increases sharply.
2. The PTC thermistor relay detects the change and indicates motor overtemperature
through its output contacts.
3. The opening contacts of the PTC relay(s) switch off the voltage to terminal X113:4 of
the FSO module (this is configured as the input of the STO [or SS1] function in the FSO
module).
4. The FSO module opens the STO circuit of the drive either immediately (STO function)
or after a deceleration ramp (SS1 function). This prevents the drive from generating the
torque required to rotate the motor.
5. The drive generates an STO indication (parameter 31.22).
6. The FSO module generates an STO indication (parameter FSOGEN.61).
7. If the auxiliary contacts of the PTC relay(s) are wired to a digital input, the loss of the
signal triggers a motor overtemperature indication.
8. After the motor temperature has decreased to normal, the user resets the PTC relay(s)
using remote reset buttons (or the buttons on the PTC relays themselves). See the
circuit diagrams of the delivery.
9. Optional: The user resets the drive faults either from the reset source defined by the
user (parameter 31.11) or locally with the drive control panel:
• the STO fault in the drive (if configured with drive parameter 31.22)
• the motor overtemperature fault in the drive (if configured).
10. Optional: The user resets the safety function in the FSO module with the reset button
(if a reset circuit is wired and configured).