Danfoss VLT 8000 AQUA series, Руководство по эксплуатации, Страница: 104 / 206

VLT
®
8000 AQUA
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 frequency converter 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 .
VLT 8152-8602, 380-460 V and VLT 8052-8652,
525-690 V work with a reduced DC current. The level
can, depending on motor selection, be down to 80%.
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.
✭
10 sec.
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 frequency converter is able to monitor the motor
temperature in two different ways:
- Via a thermistor sensor fitted to the motor. The
thermistor is connected to one of the analog
input terminals 53 and 54.
- Calculation of the thermal load (ETR - Electronic
Thermal Relay), based on the current load and
the time. This is compared with the rated motor
current I
M,N
and the rated motor frequency f
M,N
.
The calculations made take into account the
need for a lower load at lower speeds because
of less cooling in the motor itself.
ETR functions 1-4 do not start calculating the load until
there is a switch-over to the Setup in which they were
selected. This enables the use of the ETR function,
even where two or several motors alternate.
Description of choice:
Select No protection [0] if no warning or tripping is
required when the motor is overloaded.
Select Thermistor warning [1] if a warning is desired
when the connected thermistor gets too hot.
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.83.A2.02 - VLT is a registered Danfoss trademark
104