Mechanical Brake Control; Serial Communication - Danfoss VLT AQUA Drive FC 200 Operating Instructions Manual

Installation

2.4.5.9 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
2 2 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 Mechanical brake control [32] in par. 5-4*
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
perfectly safe mode during the entire operation. Because
the 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.
L1 L2
U V
Motor
Illustration 2.24 Connecting the Mechanical Brake to the
frequency converter
22
VLT
Operating Instructions
L3
Drive
Output
relay
W
02 01
Mechanical
Brake
Output
A1
Contactor
Input
Shaft A2
Brake Power Circuit
380Vac
MG.20.M8.02 - VLT
®
AQUA Drive

2.4.6 Serial Communication

Connect RS-485 serial communication wiring to terminals
(+)68 and (-)69.
•
Screened serial communication cable is
recommended
•
See 2.4.2 Earth (Grounding) Requirements for
proper grounding
Illustration 2.25 Serial Communication Wiring Diagram
For basic serial communication set up, select the following
1. Protocol type in 8-30 Protocol.
2. Frequency converter address in 8-31 Address.
3. Baud rate in 8-32 Baud Rate.
•
Four communication protocols are internal to the
frequency converter. Follow motor manufacturer
wiring requirements.
•
Functions can be programmed remotely using
the protocol software and RS-485 connection or
in parameter group 8-** Communications and
Command Circuit
Options
220Vac
•
Selecting a specific communication protocol
changes various default parameter settings to
match that protocol's specifications along with
Frewheeling
making additional protocol-specific parameters
diode
available
•
Option cards which install into the frequency
converter are available to provide additional
communication protocols. See the option-card
documentation for installation and operation
instructions
®
is a registered Danfoss trademark
61
68 +
RS-485
69
Danfoss FC
Modbus RTU
®
Johnson Controls N2