Yaskawa Varispeed-656 DC5 - Manual (Page 70)

E-60
„ When the Power Supply is a Generator
• Use the VS-656DC5 that is exclusively for generators. (For further information, contact
your YASKAWA representative.)
• Select the generator capacity approx. twice as large as the VS-656DC5 input power sup-
ply capacity. (For further information, contact your YASKAWA representative.)
• Set such deceleration time or load so that the regenerative power from the motor will be
10% or less of the generator capacity.
„ When A Phase Advance Capacitor or Thyristor Controller Is Provided
for the Power Supply
No phase advance capacitor is needed for the VS-656DC5. Installing one on the VS-
656DC5 will result in reduction of power factor.
For the phase advance capacitor that has already been installed on the same power supply
system as the VS-656DC5, attach a series reactor to prevent oscillation with the VS-
656DC5.
Contact your YASKAWA representative, if any derive generaing voltage surge or voltage
distortion such as DC motor drive thyristor controller or magnetic agitator is installed on the
same power supply system.
„ Prevention from EMC (Radio Noise) or Harmonics Leak Current
No preventive action from harmonics current is needed. However, some preventive actions
from EMC (radio noise) or harmonics leak current are necessary as well as the general
inverter drives.
If any device that is apt to be affected by noise is near the VS-656DC5, use a noise filter of
the above-mentioned reactor type (zero-phase reactor).
Use a leakage relay or an earth leakage breaker designed for Inverters (products provided
with prevention from harmonics leak current), when necessary.
„ Guideline for Harmonics Reduction
The guideline for harmonics is available for users who receive 6.6 kV or more from the
power supply system.
„ Influence by Power Supply Distortion
When the power supply voltage is distorted, or when several devices are connected in paral-
lel to the same power supply, the harmonics contents become larger since the harmonics of
the power supply system enter the VS-656DC5.