Programming Of Torque Limit And Stop; Automatic Motor Adaptation (Ama) - Danfoss FC 300 Design Manual

7. Application Examples

7.1.7. Programming of Torque Limit and Stop

In applications with an external electro-mechanical brake, such as hoisting applications, it is pos-
sible to stop the adjustable frequency drive via a 'standard' stop command and simultaneously
activate the external electro-mechanical brake.
The example given below illustrates the programming of adjustable frequency drive connections.
The external brake can be connected to relay 1 or 2, see paragraph
Brake
terminal 29 to Terminal mode 29 Output [1] and Torque limit & stop [27].
Description:
If a stop command is active via terminal 18 and the adjustable frequency drive is not at the torque
limit, the motor ramps down to 0 Hz.
If the adjustable frequency drive is at the torque limit and a stop command is activated, terminal
29 Output (programmed to Torque limit and stop [27]) is activated. The signal to terminal 27
changes from 'logic 1' to 'logic 0', and the motor starts to coast, thereby ensuring that the hoist
stops even if the adjustable frequency drive itself cannot handle the required torque (i.e., due to
excessive overload).
7
-
-
-
-

7.1.8. Automatic Motor Adaptation (AMA)

AMA is an algorithm used to measure the electrical motor parameters of a motor at standstill. This
means that AMA itself does not supply any torque.
AMA is useful when commissioning systems and optimizing the adjustment of the adjustable fre-
quency drive to the applied motor. In particular, this feature is used where the default setting
does not apply to the connected motor.
Par. 1-29 allows a choice of complete AMA with determination of all electrical motor parameters,
or reduced AMA with determination of only the stator resistance, Rs.
The duration of a total AMA varies from a few minutes on small motors, to more than 15 minutes
on large motors.
Limitations and preconditions:
•
•
146
. Program terminal 27 to Coast, inverse [2] or Coast and Reset, inverse [3], and program
Start/stop via terminal 18
Par. 5-10 Start [8]
Quickstop via terminal 27
Par. 5-12 Coast inverse [2]
Terminal 29 Output
Par. 5-02 Terminal 29 Mode Output
[1]
Par. 5-31 Torque Limit & Stop [27]
Relay output [0] (Relay 1)
Par. 5-40 Mechanical Brake Control
[32]
For the AMA to optimally determine the motor parameters, enter the correct motor
nameplate data in par. 1-20 to 1-26.
For the best adjustment of the adjustable frequency drive, carry out an AMA on a cold
motor. Repeated AMA runs may lead to a heating of the motor, which results in an in-
crease of the stator resistance, Rs. Normally, this is not critical.
MG.33.B9.22 - VLT ® is a registered Danfoss trademark.
FC 300 Design Guide
Control of Mechanical