VLT
®
8000 AQUA
■
DC braking
In DC braking, the motor receives a DC current
that brings the shaft to a halt. Parameter 114
DC
braking current
, decides the DC braking current as
a percentage of the rated motor current I
M,N
.
In parameter 115
DC braking time
, the DC braking
time is selected, and in parameter 116
DC brake
cut-in frequency
, the frequency is selected at
which DC braking becomes active.
If terminal 19 or 27 (parameter 303/304
Digital
input
) has been programmed to
DC braking
inverse
and shifts from logic "1" to logic "0",
the DC braking will be activated.
When the start signal on terminal 18 changes
from logic "1" to logic "0", the DC braking will
be activated when the output frequency becomes
lower than the brake coupling frequency.
NOTE
The DC brake is not to be used if the inertia
of the motor shaft is more than 20 times
the inertia of the motor itself.
114 DC braking current
(DC BRAKE CURRENT)
Value:
✭
50 %
The maximum value depends on the rated motor
current. If the DC braking current is active, the
AFD has a switching frequency of 4 kHz.
Function:
This parameter is used for setting the DC braking
current that is activated upon a stop when the DC
brake frequency set in parameter 116,
DC brake
cut-in frequency
has been reached, or if DC brake
inverse is active via terminal 27 or via the serial
communication port. The DC braking current will
be active for the duration of the DC braking time
set in parameter 115
DC braking time
.
Description of choice:
To be set as a percentage value of the rated motor
current I
M,N
set in parameter 105 Motor current, I
VLT,N
.
100% DC braking current corresponds to I
M,N
.
Make sure not to supply too high a
braking current for too long.The motor
will be damaged because of mechanical
overload or the heat generated in the motor.
115 DC braking time
(DC BRAKE TIME)
Value:
0.0 - 60.0 sec.
✭
OFF
Function:
This parameter is for setting the DC braking time
for which the DC braking current (parameter
113) is to be active.
Description of choice:
Set the desired time.
116 DC brake cut-in frequency
(DC BRAKE CUT-IN)
Value:
0.0 (OFF) - par. 202
Output frequency high limit, f
MAX
✭
OFF
Function:
This parameter is used for setting the DC brake cut-in
frequency at which DC braking is to be activated
in connection with a stop command.
Description of choice:
Set the desired frequency.
117 Motor thermal protection
(MOT. THERM PROTEC)
Value:
No protection (NO PROTECTION)
[0]
Thermistor warning (THERMISTOR WARNING)
[1]
Thermistor trip (THERMISTOR FAULT)
[2]
ETR Warning 1 (ETR WARNING 1)
[3]
✭
ETR Trip 1 (ETR TRIP 1)
[4]
ETR Warning 2 (ETR WARNING 2)
[5]
ETR Trip 2 (ETR TRIP 2)
[6]
ETR Warning 3 (ETR WARNING 3)
[7]
ETR Trip 3 (ETR TRIP 3)
[8]
ETR Warning 4 (ETR WARNING 4)
[9]
ETR Trip 4 (ETR TRIP 4)
[10]
Function:
The AFD is able to monitor the motor temperature
in two different ways:
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.80.A7.22 - VLT is a registered Danfoss trademark
98
Rosewood STP ST42 General (Operation and Maintenance Manual - Part 4:
Section 6.3 Manufacturers Manuals 6.3.33 Danfoss VLT Aquadrive 8000) Vendor Manual
QP Id: VM207
Active: 03/09/2013
Page 104 of 208
