Safety And Protections; Emergency Stop; Thermal Motor Protection - ABB ACS850 Manual

80 Program features

Safety and protections

Emergency stop

Note: The user is responsible for installing the emergency stop devices and all the
additional devices needed for the emergency stop to fulfil the required emergency
stop category classes. For more information, contact your local ABB representative.
The emergency stop signal is to be connected to the digital input which is selected as
the source for the emergency stop activation (par.
stop off1). Emergency stop can also be activated through fieldbus
cw or 02.36 EFB main
Note: When an emergency stop signal is detected, the emergency stop function
cannot be cancelled even though the signal is cancelled.

Thermal motor protection

The motor can be protected against overheating by
• the motor thermal protection model
• measuring the motor temperature with PTC, Pt100 or KTY84 sensors. This will
result in a more accurate motor model.
Thermal motor protection model
The drive calculates the temperature of the motor on the basis of the following
assumptions:
1) When power is applied to the drive for the first time, the motor is at ambient
temperature (defined by parameter
is applied to the drive, the motor is assumed to be at the estimated temperature.
2) Motor temperature is calculated using the user-adjustable motor thermal time and
motor load curve. The load curve should be adjusted in case the ambient
temperature exceeds 30 °C.
It is possible to adjust the motor temperature supervision limits and select how the
drive reacts when overtemperature is detected.
Note: The motor thermal model can be used when only one motor is connected to
the inverter.
cw).
31.09 Mot ambient
10.13 Em stop off3
(02.22 FBA main
temp). After this, when power
or 10.15 Em