Digistart D3: User Guide
107
Issue: G
10.8.1 Commissioning
1. Configure the Digistart D3 as follows:
Parameter settings:
•
Pr 4D
Relay B Action
•
Select 'Changeover contactor'
•
Pr 4E
Relay B On Delay
•
Set this to the maximum time (5m:00s).
•
Pr 13A
Motor Data-1 Ramp
•
Select 'Dual Ramp' (for slip-ring induction motor control)
•
Pr 13D
Changeover Time
•
Default setting is 150 milliseconds. Set this to a value just greater than the changeover contactor (K1)
pole closing time.
•
Pr 13C
Slip Ring Retard
•
Default setting is 50%. Set this parameter to a value which is high enough to cause the motor to
instantly accelerate once the rotor resistance (R1) has been bridged out and low enough to avoid a
motor current pulse.
2. Start the motor under normal load conditions and record the time it takes to reach a constant speed with external
rotor resistance (R1) in the circuit. Stop the motor soon after a constant speed has been reached. Change Pr 4E
to the recorded time value.
3. Start the motor under normal load conditions and monitor the motor speed behaviour and motor current when the
changeover contactor (K1) switches in to short-out the rotor resistance (R1).
If the motor does not accelerate immediately after changeover, increase the setting of Pr 13C.
If there is a pulse in motor current immediately after changeover, reduce the setting of Pr 13C.
S
peed
3
Time
1
R1 Constant Speed
5
Pr 4E
Relay B On Delay
2
First ramp
6
K1 closes
3
Second ramp
7
Pr 13D
Changeover Time
4
Run mode (I < 120% FLC)
NOTE
For this installation to function correctly, only use the primary motor settings with constant current start
method (Pr 2A
Start Mode
).
