Additional Connections; Mechanical Brake Control - Danfoss VLT AQUA Drive FC 200 Operating Instructions Manual

How to Install
NOTE
Unsuccessful AMA is often caused by incorrectly registered
motor name plate data or a too big difference between
the motor power size and the frequency converter power
size.
Step 4. Set speed limit and ramp time
3-02 Minimum Reference
3-03 Maximum Reference
Set up the desired limits for speed and ramp time
4-11 Motor Speed Low Limit [RPM] or 4-12 Motor
Speed Low Limit [Hz]
4-13 Motor Speed High Limit [RPM] or 4-14 Motor
Speed High Limit [Hz]
3-41 Ramp 1 Ramp up Time
3-42 Ramp 1 Ramp Down Time

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 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* 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.
4.10.2 Parallel Connection of Motors
The frequency converter can control several parallel-
connected motors. The total current consumption of the
motors must not exceed the rated output current I
the frequency converter.
VLT AQUA Low Harmonic Drive Operating Instructions
NOTE
Installations with cables connected in a common joint as in
Illustration 4.42, is only recommended for short cable
lengths.
NOTE
When motors are connected in parallel, 1-29 Automatic
Motor Adaptation (AMA) cannot be used.
NOTE
The electronic thermal relay (ETR) of the frequency
converter cannot be used as motor protection for the
individual motor in systems with parallel-connected
motors. Provide further motor protection by e.g.
thermistors in each motor or individual thermal relays
(circuit breakers are not suitable as protection).
Illustration 4.42
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.
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MG20T202 - VLT is a registered Danfoss trademark
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