Kruger Ecowatt K320 Series Operation Manual page 283

Ecowatt Drive K320 series
®
8.4 Capacitor
8.4.1 Capacitor reforming
If the VFD has been left unused for a long time, you need to follow the instructions to reform
the DC bus capacitor before using it. The storage time is calculated from the date the VFD is
delivered.
Storage time
Less than 1 year
1 to 2 years
2 to 3 years
More than 3 years
The method for using a voltage controlled power supply to charge the VFD is described as
follows:
The selection of a voltage controlled power supply depends on the power supply of the VFD.
For VFDs with an incoming voltage of 1PH/3PH 230 V AC, you can use a 230 V AC/2 A voltage
regulator. Both 1PH and 3PH VFDs can be charged with a 1PH voltage controlled power supply
(connect L+ to R, and N to S or T). All the DC bus capacitors share one rectifier, and therefore
they are all charged.
For VFDs of a high voltage class, ensure that the voltage requirement (for example, 380 V) is
met during charging. Capacitor changing requires little current, and therefore you can use a
small-capacity power supply (2 A is sufficient).
The method for using a resistor (incandescent lamp) to charge the drive is described as
follows:
If you directly connect the drive device to a power supply to charge the DC bus capacitor, it
needs to be charged for a minimum of 60 minutes. The charging operation must be performed
at a normal indoor temperature without load, and you must connect a resistor in series mode
in the 3PH circuit of the power supply.
For a 380 V drive device, use a resistor of 1 kΩ/100W. If the voltage of the power supply is no
higher than 380 V, you can also use an incandescent lamp of 100W. If an incandescent lamp is
used, it may go off or the light may become very weak.
No charging operation is required.
The VFD needs to be powered on for 1 hour before the first running
command.
Use a voltage controlled power supply to charge the VFD:
Charge the VFD at 25% of the rated voltage for 30 minutes, and then
charge it at 50% of the rated voltage for 30 minutes, at 75% for another
30 minutes, and finally charge it at 100% of the rated voltage for 30
minutes.
Use a voltage controlled power supply to charge the VFD:
Charge the VFD at 25% of the rated voltage for 2 hours, and then charge
it at 50% of the rated voltage for 2 hours, at 75% for another 2 hours,
and finally charge it at 100% of the rated voltage for 2 hours.
Operation instruction
-274-
Maintenance