ABB ACS880 Series Firmware Manual page 85

Earth (Ground) fault detection (parameter 31.20)
The earth fault detection function is based on sum current measurement. Note that
• an earth fault in the supply cable does not activate the protection
• in a grounded supply, the protection activates within 2 milliseconds
• in an ungrounded supply, the supply capacitance must be 1 microfarad or more
• the capacitive currents caused by shielded motor cables up to 300 meters will not
activate the protection
• the protection is deactivated when the drive is stopped.
Supply phase loss detection (parameter 31.21)
The parameter selects how the drive reacts whenever a supply phase loss is
detected.
Safe torque off detection (parameter 31.22)
The drive monitors the status of the Safe torque off input, and this parameter selects
which indications are given when the signals are lost. (The parameter does not affect
the operation of the Safe torque off function itself). For more information on the Safe
torque off function, see the Hardware manual.
Swapped supply and motor cabling (parameter 31.23)
The drive can detect if the supply and motor cables have accidentally been swapped
(for example, if the supply is connected to the motor connection of the drive). The
parameter selects if a fault is generated or not. Note that the protection should be
disabled in drive/inverter hardware supplied from a common DC bus.
Stall protection (parameters 31.24...31.28)
The drive protects the motor in a stall situation. It is possible to adjust the supervision
limits (current, frequency and time) and choose how the drive reacts to a motor stall
condition.
Overspeed protection (parameter 31.30)
The user can set overspeed limits by specifying a margin that is added to the
currently-used maximum and minimum speed limits.
Ramp stop supervision (parameters 31.32, 31.33,
The control program has a supervision function for both the normal and emergency
stop ramps. The user can either define a maximum time for stopping, or a maximum
deviation from the expected deceleration rate. If the drive fails to stop in the expected
manner, a fault is generated and the drive coasts to a stop.
Program features 85
31.37 and 31.38)