Danfoss VLT 2800 Design Manual page 74

Programming
output frequency equals parameter 130 Start frequency and
the output voltage is equal to parameter 131 Voltage at
start. This functionality is used typically for hoist
applications with counterweight. It is particularly used in
for applications in which a cone anchor motor is applied.
The cone anchor motor can break away using parameter
130 Start frequency and parameter 131 Voltage at start.
4 4
122 Function at stop
Value:
Coasting (COAST)
DC hold (DC HOLD)
Function:
Select the function of the frequency converter after the
output frequency has become lower than the value in
parameter 123 The min. frequency for activation of function
at stop or after a stop command and when the output
frequency has been ramped down to 0 Hz.
Description of choice:
Select [0] Coasting if the frequency converter is to 'let go'
of the motor (inverter turned off).
Select [1] DC hold if parameter 137 DC hold voltage is to be
activated.
Min. frequency for activation of function at
123
stop
Value:
0,1-10 Hz
Function:
In this parameter, the output frequency is set at which the
function selected in parameter 122 Function at stop is to be
activated.
Description of choice:
Set the required output frequency.
If parameter 123 is set too high, and DC hold has been
select in parameter 122, the output frequency jumps to the
value in parameter 123 without ramping up. This may
cause an overcurrent warning / alarm.
NOTICE
If parameter 123 is set higher than parameter 130, then
the start delay function (parameters 120 and 121) is
skipped.
CAUTION
If parameter 123 is set too high, and DC hold is selected
in parameter 122, the output frequency jumps to the
value in parameter 123 without ramping up. This may
cause an overcurrent warning or alarm.
During DC braking DC voltage is supplied to the motor,
and this causes the shaft to be brought to a standstill. In
parameter 132 DC brake voltage DC brake voltage can be
preset from 0-100%. Max. DC brake voltage depends on
the motor data selected.
72
Design Guide
In parameter 126 DC braking time DC braking time is
determined, and in parameter 127 DC brake cut-in frequency
the frequency at which DC braking becomes active is
selected. If a digital input is programmed to [5] DC braking
inverse and shifts from logic '1' to logic '0', DC braking is
activated. When a stop command becomes active, DC
braking is activated when the output frequency is less than
the brake cut-in frequency.
[0] Do not use DC braking if the inertia in the motor shaft is
more than 20 times greater than the motor's internal
[1]
inertia.
In this parameter, the DC brake time is set at which
parameter 132 DC brake voltage is to be active.
Set the required time.
0,1 Hz
In this parameter, the DC brake cut-in frequency is set at
which the DC brake is to be activated in connection with a
stop command.
Set the required frequency.
The frequency converter can monitor the motor
temperature in 2 different ways:
Danfoss A/S © Rev. May/2014 All rights reserved.
WARNING
126 DC brake time
Value:
0 - 60 s
Function:
Description of choice:
127 DC brake cut-in frequency
Value:
0.0 (OFF) - par. 202
Output frequency high limit, f
MAX
Function:
Description of choice:
128 Thermal motor protection
Value:
No protection (NO PROTECTION)
Thermistor warning
(THERMISTOR WARN)
Thermistor trip (THERMISTOR TRIP)
ETR warning 1 (ETR WARNING 1)
ETR trip 1 (ETR TRIP 1)
ETR warning 2 (ETR WARNING 2)
ETR trip 2 (ETR TRIP 2)
ETR warning 3 (ETR WARNING 3)
ETR trip 3 (ETR TRIP 3)
ETR warning 4 (ETR WARNING 4)
ETR trip 4 (ETR TRIP 4)
Function:
10 s
OFF
[0]
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
MG27E402