Thermal Motor Protection - ABB ACSM1 Firmware Manual

(±360/polepairs)° in order to determine the rotor position. In case 2 (open-loop
control), the shaft is turned only in one direction and the angle is smaller.
The standstill modes can be used if the motor cannot be turned (for example, when
the load is connected). As the characteristics of motors and loads differ, testing must
be done to find out the most suitable standstill mode.
The drive is also capable of determining the rotor position when started to a running
motor in open-loop or closed-loop modes. In this situation, the setting of
AUTOPHASING MODE
Rotor

Thermal motor protection

With the parameters in group
overtemperature protection and configure motor temperature measurement (if
present). This block also shows the estimated and measured motor temperature.
The motor can be protected against overheating by
• the motor thermal protection model
• measuring the motor temperature with PTC 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
(value of 1.18 MOTOR TEMP
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.
has no effect.
N
S
45 MOT THERM
45.05 AMBIENT
EST, saved at power switch-off).
Absolute encoder/resolver
PROT, the user can set up the motor
TEMP). After this, when power
Drive control and features
41
11.07