9.4.1 Capacitors reforming
The DC bus capacitors must be reformed according to the operation instruction if the VFD has been stored for a long time. The storing time is counted form the producing date other than the delivery data which has been marked in the serial number of the VFD.
Time | Operational principle |
Storing time less than 1 year | Operation without charging |
Storing time 1-2 years | Connect with the power for 1 hour before first ON command |
Storing time 2-3 years | Use power surge to charge for the VFD |
Storing time more than 3 years | Use power surge to charge for the VFD |
Use voltage-adjusting power supply to charge the VFD:
The right selection of the voltage-adjusting power supply depends on the supply power of the VFD. Single phase 220 V AC/2A power surge is applied to the VFD of single/three-phase 220 V AC. The VFD of single/three-phase 220 V AC can apply single phase 220 V AC/2A power surge (L+ to R, N to S or T). All DC bus capacitors can charge at the same time because there is one rectifier.
High-voltage VFD needs enough voltage (for example, 380 V) during charging. The small capacitor power (2A is enough) can be used because the capacitor needs little current when charging.
The operation method of VFD charging through resistors (LEDs):
The charging time is at least 60 minutes if charge the DC bus capacitor directly through supply power. This operation is available on normal temperature and no-load condition and the resistor should be serially connected in the 3-phase circuits of the power supply:
a) 380 V driven device: 1k/100W resistor. LED of 100W can be used when the power voltage is no more than 380 V. But if used, the light may be off or weak during charging.
b) 660 V drive device: 1k/160W resistor.
Figure 9‑1 380 V charging illustration of the driven device
9.4.2 Change electrolytic capacitors
| Read and follow the instructions in Chapter 1 "Safety precautions". Ignoring the instructions may cause physical injury or death, or damage to the equipment. |
An electrolytic capacitor must be replaced if it has been used for more than 35,000 hours. For details about the replacement, contact the local INVT office, or our national service hotline (400-700-9997).