1-76 Start Current
Range: Function:
0 A* [ 0 - par. 1-24
A]
Some motors, for example cone
rotor motors, need extra current/
starting speed to disengage the
rotor. To obtain this boost, set the
required current in
parameter 1-76 Start Current. Set
parameter 1-74 Start Speed [RPM].
Set parameter 1-72 Start Function to
[3] Start speed cw or [4] Horizontal
operation, and set a start delay time
in parameter 1-71 Start Delay.
This parameter can be used for
hoist applications (cone rotor).
1-77 Compressor Start Max Speed [RPM]
Range: Function:
Size
related*
[ 0 - par. 4-13
RPM]
Use this parameter to set the speed
range for high starting torque.
Above the set speed, normal torque
and current limits are used. Setting
the parameter value to zero
disables the function.
1-78 Compressor Start Max Speed [Hz]
Range: Function:
Size
related*
[ 0 - par. 4-14
Hz]
Use this parameter to set the speed
range for high starting torque.
Above the set speed, normal torque
and current limits are used. Setting
the parameter value to zero
disables the function.
1-79 Compressor Start Max Time to Trip
Range: Function:
5 s* [0 - 10 s] This parameter refers to the start
function selected in
parameter 1-72 Start Function.
Enter the time delay required
before commencing acceleration.
This parameter enables a trip if
compressor starting takes too long
time. If the speed cannot reach the
value set in
parameter 1-77 Compressor Start
Max Speed [RPM] within the
specied time, the rotor is
considered blocked and the
frequency converter trips. The time
includes any time set in
parameter 1-71 Start Delay.
4.2.8 1-8* Stop Adjustments
1-80 Function at Stop
Option: Function:
Select the frequency converter
function after a stop command or
after the speed is ramped down to
the settings in parameter 1-81 Min
Speed for Function at Stop [RPM].
[0] * Coast Leaves motor in free mode. The
motor is disconnected from the
frequency converter.
[1] DC hold Energizes the motor with a DC hold
current (see parameter 2-00 DC Hold
Current).
[3] Pre-
magnetizing
Builds up a magnetic eld while the
motor is stopped. This allows the
motor to produce torque quickly at
subsequent start commands
(asynchronous motors only). This
premagnetizing function does not
help the very rst start command.
Two dierent solutions are available
to premagnetize the machine for
the rst start command:
•
Start the frequency
converter with a 0 RPM
reference and wait 2-4
rotor time constants
before increasing the
speed reference.
•
Use the start delay with
DC hold:
•
Set
parameter 1-71 St
art Delay to the
required premag-
netizing time (2–
4 rotor time
constants). See
the time
constants
description
further in this
section).
•
Set
parameter 1-72 St
art Function to
either [0] DC hold
or [1] DC Brake.
•
Set the DC hold
or DC brake
Parameter Descriptions Programming Guide
MG06J202 Danfoss A/S © 03/2019 All rights reserved. 45
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