ABB ACQ810, Firmware Manual

Page: 78 / 376

78 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.
10.13 Em stop off3 or 10.15 Em
stop off1 ). Emergency stop can also be activated through fieldbus ( 02.22 FBA main
cw or 02.36 EFB main cw ).
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 1…3 PTC 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
31.09 Mot ambient temp ). After this, when power
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.
Temperature measurement
It is possible to detect motor overtemperature by connecting a motor temperature
sensor b24 V and digital input DI5 on the drive.
Constant current is fed through the sensor. The resistance of the sensor increases as
the motor temperature rises over the sensor reference temperature
T
ref
, as does the
voltage over the resistor. The temperature measurement function reads the voltage
and converts it into ohms.