Yaskawa Varispeed 626M5 - Manual (Page 61)

3.3 Wiring Main Circuit Terminals
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3.3.5 Wiring the Main Circuit
This section provides information on the main circuits of the Converter and Inverter and information on
wiring the ground lines.
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Wiring Precautions for Main Circuit Input
Installation of Molded-case Circuit Breaker (MCCB)
Make sure to connect MCCB between the main circuit power supply input and VS-656MR5 input termi-
nals R/L1, S/L2 and T/L3 to protect wiring.
Installation of Ground Fault Interrupter
The output of the Inverter is switched at high speed, which results in high-frequency leakage current. When
connecting a ground fault interrupter to the input terminals of the Converter, select an one designed for
inverters that eliminates the high-frequency leakage current and detects only the leakage current in fre-
quency bands that are harmful to the human body.
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Use a ground fault interrupter designed for inverters for each Converter, with a minimum sensing cur-
rent of 30 mA.
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A standard ground fault interrupter can be used for each Converter provided that it has a minimum
sensing current of 200 mA with a minimum response time of 0.1 s.
Installation of Magnetic Contactor
When the main circuit power supply is shut OFF in the sequence, a magnetic contactor (MC) can be used
instead of a molded-case circuit breaker (MCCB). However, when a magnetic contactor is switched OFF
at the main circuit power supply input side, regenerative braking does not function and the motor coasts
to a stop. (At this time, protective function activates to display a fault.)
Frequent turning ON and OFF the magnetic contactor for the main circuit power supply input may cause
the Converter and Inverter to malfunction. Turn the magnetic contactor ON and OFF once every 30 min-
utes at most.
Terminal Block Connection Sequence
Main circuit power supply input phases can be connected to any terminal regardless of the order of R/L1,
S/L2 and T/L3 on the terminal block.
Installation of AC Reactor
Make sure to install an AC reactor, which corresponds to the capacity of the individual Converter, to each
Converter for the Converter’s power-supply regeneration.
Do not connect any equipment other than the Converter to the secondary side of the AC reactor. If this
caution is not observed, an overcurrent may occur in the Converter. An AC reactor is effective in improving
the power factor of the power supply side.
Installation of Surge Suppressor
For inductive loads (magnetic contactors, magnetic relays, magnetic valves, solenoids, magnetic brakes,
etc.) connected near the inverter, install a surge suppressor.
A surge absorber is used to absorb energy accumulated in the coil of an inductive load. Use a surge absorber
with a capacity suitable for the coil. Do not, however, connect surge absorbers to output terminals U, V, W
of the Inverter. If a surge absorber is not used, the generated surge voltage of the coil will affect the control
signal line of the Inverter when the inductive load is turn ON and OFF. As a result, the control signal may
malfunction.
Prohibition of Installation of Phase Advancing Capacitor
Do not connect a phase advancing capacitor or surge suppressor to main circuit power supply input (R/L1,
S/L2, or T/L3). The phase advancing capacitor or surge suppresser may become overheated and damaged
by the harmonic components of the drive unit. Also, the drive unit may malfunction because of overcur-
rent.
Using Input Noise Filters
A noise filter installed on the power supply side eliminates external noise on the power line of the Inverter
and suppresses harmonic noise leaking from the Inverter to the power line. Use a noise filter designed for
an inverter, as shown in example 1. Refer to 14.3.7 Noise Filter for recommended filters.
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IMPORTANT