4.8.5 Mechanical Brake Control
In hoisting/lowering applications, it is necessary 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 keep the
motor at standstill, 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 value in
parameter 2-20 Release Brake
Current
.
•
The brake is engaged when the output frequency
is less than the frequency set in
parameter 2-21 Activate Brake Speed [RPM]
or
parameter 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
overvoltage situation, the mechanical brake immediately
closes.
NOTICE
The frequency converter is not a safety device. It is the
responsibility of the system designer to integrate safety
devices according to relevant national crane/lift
regulations.
130BA902.10
L1
L2
L3
U
V
W
02
01
A1
A2
Frequency converter
Output
relay
Command circuit
220 V AC
Mechanical
brake
Shaft
Motor
Frewheeling
diode
Brake
380 V AC
Output
contactor
input
power circuit
Illustration 4.11 Connecting the Mechanical Brake to the
Frequency Converter
4.8.6 RS485 Serial Communication
Connect RS485 serial communication wiring to terminals
(+)68 and (-)69.
•
Use screened serial communication cable
(recommended).
•
See
for proper grounding.
61
68
69
+
130BB489.10
RS-485
Illustration 4.12 Serial Communication Wiring Diagram
For basic serial communication set-up, select the following:
1.
Protocol type in
parameter 8-30 Protocol
.
2.
Frequency converter address in
parameter 8-31 Address
.
3.
Baud rate in
parameter 8-32 Baud Rate
.
•
2 communication protocols are internal to the
frequency converter:
-
Danfoss FC.
-
Modbus RTU
•
Functions can be programmed remotely using
the protocol software and RS485 connection or in
parameter group
8-** Communications and
Options.
•
Selecting a specific communication protocol
changes various default parameter settings to
match that protocol’s specifications and makes
additional protocol-specific parameters available.
•
Option cards for the frequency converter are
available to provide additional communication
protocols. See the option card documentation for
installation and operation instructions.
Electrical Installation
VLT
®
AutomationDrive FC 301/302
20
Danfoss A/S © 07/2015 All rights reserved.
MG33AQ02
4
4
Summary of Contents for VLT AutomationDrive FC 301
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