![Danfoss FC 300 Design Manual Download Page 213](http://html.mh-extra.com/html/danfoss/fc-300/fc-300_design-manual_507599213.webp)
9.1.6 Closed-loop Drive System
A drive system consist usually of more elements such as:
•
Motor
•
Add
(Gearbox)
(Mechanical Brake)
•
AutomationDrive FC 302 AutomationDrive
•
Encoder as feedback system
•
Brake resistor for dynamic braking
•
Transmission
•
Load
Applications demanding mechanical brake control will usually need a
brake resistor.
Figure 9.1:
Basic Set-up for AutomationDrive FC 302
Closed-loop Speed Control
9.1.7 Programming of Torque Limit and Stop
In applications with an external electro-mechanical brake, such as hoisting applications, it is possible 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
Control of Mechanical Brake
. Program terminal 27 to Coast, inverse [2] or Coast and
Reset, inverse [3], and program 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).
-
Start/stop via terminal 18
par. 5-10
Terminal 18 Digital Input
Start [8]
-
Quickstop via terminal 27
par. 5-12
Terminal 27 Digital Input
Coasting Stop, Inverse [2]
-
Terminal 29 Output
par. 5-02
Terminal 29 Mode
Terminal 29 Mode Output [1]
par. 5-31
Terminal 29 digital Output
Torque Limit & Stop [27]
-
Relay output [0] (Relay 1)
par. 5-40
Function Relay
Mechanical Brake Control [32]
FC 300 Design Guide
9 Application Examples
MG.33.BC.22 - VLT
®
is a registered Danfoss trademark
9-3
9