Danfoss iC2 Application Manual page 170

Application Guide | iC2-Micro Frequency Converters
Selection number Selection name
3 Pre-magnetizing
10 Coast With Stop at Low Reference
11 DC Hold With Stop at Low Reference
P 5.7.2 Min Speed for Function at Stop [Hz]
Use this parameter to set the output frequency at which to activate P 5.7.1 Function at Stop.
Default value:
0.0
Parameter
182
number:
Data type:
uint16
P 5.7.3 DC Brake Time
Set the duration of the DC brake current set in P 5.7.4 DC Brake Current %, once activated.
Default value:
10.0
Parameter
202
number:
Data type:
uint16
170
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Selection description
Builds up a magnetic field while the motor is stopped. This allows
the motor to produce torque quickly at commands (induction
motors only). This premagnetizing function does not help the 1st
start command.
Two different solutions are available to pre-magnetize the
machine for the 1st start command:
Solution 1:
• 1. Start the frequency converter with a 0 RPM reference.
• 2. Wait 2–4 rotor time constants (see the formula below)
before increasing the speed reference.
Solution 2:
• 1. Set P 5.6.1 Start Zero Speed Time to the premagnetize time
(2–4 rotor time constants).
• 2. Set P 5.6.2 Start Function to [0] DC hold.
• 3. Set the DC hold current magnitude (P 5.7.6 DC Hold Current
% to be equal to Ipre-mag = Unom/(1.73 x Xh).
Sample rotor time constants = (Xh+X2)/(6.3*Freq_nom*Rr) 1 kW
= 0.2 s 10 kW = 0.5 s 100 kW = 1.7 s).
When a stop command is given, or a start command is removed,
and the reference is below P 5.7.2 Min Speed for Function at Stop
[Hz], the motor is disconnected from the drive.
When a stop command is given, or a start command is removed,
and the reference is below P 5.7.2 Min Speed for Function at Stop
[Hz], energizes the motor with a DC-hold current (see P 5.7.6 DC
Hold Current %).
Parameter type:
Unit:
Access type:
Parameter type:
Unit:
Access type:
Range (Size Related)
Hz
Read/Write
Range (0.0–60.0)
s
Read/Write
AB413939445838en-000301 / 130R1254