Danfoss vlt FC 102 Programming Guide

time for reducing short-circuit current to 0 and
may be susceptible to error in estimation.
•
Current testing limited to a speed range up to
300 Hz. For certain units, the limit is 250 Hz; all
200–240 V units up to and including 2.2 kW
(3 hp) and all 380–480 V units up to and
including 4 kW (5 hp).
•
For high-inertia applications (that is, where the
load inertia is more than 30 times larger than the
motor inertia), use a brake resistor to avoid
overvoltage trip during high-speed engagement
of the ying-start function.
1-77 Compressor Start Max Speed [RPM]
Range: Function:
Size
related*
[ 0 - par. 4-13
RPM]
NOTICE
Parameter 1-77 Compressor
Start Max Speed [RPM] has no
eect when
parameter 1-10 Motor
Construction = [1] PM, non-
salient SPM.
The parameter enables high
starting torque. This is a function,
where the current limit and torque
limit are ignored during start of the
motor. The time from the start
signal is given, until the speed
exceeds the speed set in this
parameter, becomes a start-zone
where the current limit and motoric
torque limit is set to what is
maximum possible for the
frequency converter/motor
combination. This parameter is
normally set to the same value as
parameter 4-11 Motor Speed Low
Limit [RPM]. When set to 0, the
function is inactive.
In this starting-zone,
parameter 3-82 Starting Ramp Up
Time is active to ensure extra
acceleration during the start and to
minimize the time where the motor
is operated under the minimum
speed for the application. The time
without protection from the current
limit and torque limit must not
exceed the value set in
parameter 1-79 Compressor Start
Max Time to Trip. If the value in
parameter 1-79 Compressor Start
Max Time to Trip is exceeded, the
frequency converter trips with
alarm 18, Start failed.
1-77 Compressor Start Max Speed [RPM]
Range: Function:
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.
1-78 Compressor Start Max Speed [Hz]
Range: Function:
Size
related*
[ 0 - par. 4-14
Hz]
NOTICE
Parameter 1-78 Compressor
Start Max Speed [Hz] has no
eect when
parameter 1-10 Motor
Construction = [1] PM, non-
salient SPM.
The parameter enables high
starting torque. This is a function,
where the current limit and torque
limit are ignored during start of the
motor. The time, from the start
signal is given until the speed
exceeds the speed set in this
parameter, becomes a start-zone
where the current limit and motoric
torque limit is set to what is
maximum possible for the
frequency converter/motor
combination. This parameter is
normally set to the same value as
parameter 4-11 Motor Speed Low
Limit [RPM]. When set to 0, the
function is inactive.
In this starting-zone,
parameter 3-82 Starting Ramp Up
Time is active instead of
parameter 3-41 Ramp 1 Ramp Up
Time to ensure extra acceleration
during the start, and to minimize
the time where the motor is
operated under the minimum
speed for the application. The time
without protection from the current
limit and torque limit must not
exceed the value set in
parameter 1-79 Compressor Start
Parameter Descriptions
VLT
®
HVAC Drive FC 102
64 Danfoss A/S © 10/2019 All rights reserved. M0010001
33

Danfoss vlt FC 102 Specifications

General

Brand	Danfoss
Model	vlt FC 102
Category	DC Drives
Language	English