Additional Connections; Mechanical Brake Control - Danfoss VLT HVAC Drive FC 100 Instruction Manual

4 How to Install

4.10 Additional Connections

4.10.1 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 adjustable frequency drive is unable to 'support' the motor, such as when the load is too
heavy, for example.
Mechanical brake control
• Select
4
• The brake is released when the motor current exceeds the preset value in par. B-20
• The brake is engaged when the output frequency is less than the frequency set in par. B-21
Brake Speed [Hz]
If the adjustable frequency drive is in alarm mode or in an overvoltage situation, the mechanical brake immediately cuts in.
4.10.2 Parallel Connection of Motors
The adjustable frequency drive can control several parallel-connected
motors. The total current consumption of the motors must not exceed
the rated output current I
NOTE!
Installation with cables connected in a common joint,
as in the figure below, is only recommended for short
cable lengths.
NOTE!
When motors are connected in parallel, par. 1-29
tomatic Motor Adaptation (AMA)
NOTE!
The electronic thermal relay (ETR) of the adjustable
frequency drive cannot be used as motor protection for
the individual motor in systems with parallel-connec-
ted motors. Provide further motor protection with, for
example, thermistors in each motor or individual ther-
mal relays (circuit breakers are not suitable for pro-
tection).
Problems may arise at start and at low RPM values if motor sizes are widely different because small motors' relatively high ohmic resistance in the stator
calls for a higher voltage at start and at low RPM values.
4-62
[32] in par. 5-4* for applications with an electro-mechanical brake.
, and only if the adjustable frequency drive carries out a stop command.
for the adjustable frequency drive.
M,N
cannot be used.
MG.16.A1.22 - VLT
VLT HVAC Low Harmonic Drive Instruction
Release Brake Current
Activate Brake Speed [RPM]
Au-
®
is a registered Danfoss trademark
.
or par. B-22 Activate
Manual