Mechanical Brake Control; Serial Communication - Danfoss FC 300 Operating Instructions Manual

Installation
Illustration 2.18 Location of Terminals 53 and 54 Switches and
Bus Termination Switch

2.4.5.8 Mechanical Brake Control

In hoisting/lowering applications, it is necessary to be able
to control an electro-mechanical brake:
•
Control the brake using any relay output or
digital output (terminal 27 or 29).
•
Keep the output closed (voltage-free) as long as
the frequency converter is unable to 'support' the
motor, for example due to the load being too
heavy.
•
Select [32] Mechanical brake control in parameter
group 5-4* Relays for applications with an electro-
mechanical brake.
•
The brake is released when the motor current
exceeds the preset value in 2-20 Release Brake
Current.
•
The brake is engaged when the output frequency
is less than the frequency set in 2-21 Activate
Brake Speed [RPM] or 2-22 Activate Brake Speed
[Hz], and only if the frequency converter carries
out a stop command.
If the frequency converter is in alarm mode or in an over-
voltage situation, the mechanical brake immediately cuts
in.
In the vertical movement, the key point is that the load
must be held, stopped, controlled (raised, lowered) in a
safe mode during the entire operation. Because the
VLT ® AutomationDrive Operating
Instructions
frequency converter is not a safety device, the crane/lift
designer (OEM) must decide on the type and number of
safety devices (e.g. speed switch, emergency brakes etc.) to
be used, in order to be able to stop the load in case of
emergency or malfunction of the system, according to
relevant national crane/lift regulations.
Illustration 2.19 Connecting the Mechanical Brake to the
Frequency Converter

2.4.6 Serial Communication

Connect RS-485 serial communication wiring to terminals
(+)68 and (-)69.
Illustration 2.20 Serial Communication Wiring Diagram
®
MG33AM02 - VLT is a registered Danfoss trademark
L1 L2 L3
Drive
U V W
Mechanical
Brake
Output
Contactor
Input
Shaft
Motor
Brake Power Circuit
380Vac
•
Screened serial communication cable is
recommended
•
See 2.4.2 Earth (Grounding) Requirements for
proper grounding
61
68
69
Output
relay
02 01
Command Circuit
220Vac
A1
Frewheeling
diode
A2
+
RS-485
19
2 2