Danfoss VLT FC 102 Programming Manual page 67

Parameter Descriptions
1-78 Compressor Start Max Speed [Hz]
Range: Function:
Max Time to Trip. If the value of
parameter 1-79 Compressor Start
Max Time to Trip is exceeded, the
frequency converter trips with
alarm 18, Start failed.
When this function is activated to
get a fast start, parameter 1-86 Trip
Speed Low [RPM] is also activated to
protect the application from
running below minimum motor
speed, for example when in current
limit.
This function allows high starting
torque and use of a fast starting
ramp. To ensure the build-up of a
high torque during the start, enter
appropriate values for start delay/
start speed/start current.
1-79 Compressor Start Max Time to Trip
Range: Function:
NOTICE
5 s [0 - 10 s]
*
Parameter 1-79 Compressor
Start Max Time to Trip has no
effect when
parameter 1-10 Motor
Construction = [1] PM, non-
salient SPM.
The time from the start signal is
given until the speed exceeds the
speed set in
parameter 1-77 Compressor Start
Max Speed [RPM] must not exceed
the time set in the parameter. If the
time set is exceeded, the frequency
converter trips with alarm 18, Start
failed.
Any time set in parameter 1-71 Start
Delay for use of a start function
must be executed within the time
limit.
3.3.10 1-8* Stop Adjustments
1-80 Function at Stop
Option: Function:
Select the frequency converter
function after a stop command and
after the speed is ramped down to
the settings in parameter 1-81 Min
Speed for Function at Stop [RPM].
M0010001
Programming Guide
1-80 Function at Stop
Option:
[0]
*
[1]
[2]
[6]
1-81 Min Speed for Function at Stop [RPM]
Range:
Size
related
*
1-82 Min Speed for Function at Stop [Hz]
Range:
Size
related
*
3.3.11 Trip at Motor Speed Low Limit
In parameter 4-11 Motor Speed Low Limit [RPM] and
parameter 4-12 Motor Speed Low Limit [Hz], it is possible to
set a minimum speed for the motor to ensure proper oil
distribution.
In some cases, for example, if operating in current limit
because of a defect in the compressor, the output motor
speed can be suppressed below motor speed low limit. To
prevent damage to the compressor, it is possible to set a
trip limit. If the motor speed drops below this limit, the
frequency converter trips and issues alarm (A49).
Reset takes place according to the selected function in
parameter 14-20 Reset Mode.
If the trip must take place at a rather exact speed (RPM),
set parameter 0-02 Motor Speed Unit for RPM and use slip
compensation, which can be set in parameter 1-62 Slip
Compensation.
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Function:
Available selections depend on
parameter 1-10 Motor Construction:
[0] Asynchronous:
[0] Coast
[1] DC hold
[2] Motor check, warning
[6] Motor check, alarm
[1] PM non-salient:
[0] Coast
Coast Leaves motor in free mode.
DC Hold/ Energizes the motor with a DC hold
Motor Preheat current (see parameter 2-00 DC
Hold/Preheat Current).
Motor check, The frequency converter issues a
warning warning if 1 or more phases are
missing.
Motor check, The frequency converter issues an
alarm alarm if 1 or more phases are
missing.
Function:
[0 - 600 Set the speed at which to activate
RPM] parameter 1-80 Function at Stop.
Function:
[ 0 - 20.0 Hz] Set the output frequency at which
to activate parameter 1-80 Function
at Stop.
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