Yaskawa Matrix Converter - Manual (Page 376)

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„ Required Time to be Ready
The MxC needs one second more than general-purpose inverters to prepare for operation. Be careful of this
delay if using an external reference input.
* This time is required if no optional device is used with the MxC. If an optional transmission device is used, the time required for the MxC to be ready for
operation will vary in accordance with the start up time of the optional transmission card.
„ Number of Motors
An MxC is capable of operating only one motor. Do not use a single MxC to operate several motors.
„ Improving the Power Factor
No AC reactor or DC reactor is required to improve the power factor.
„ Selection of Power Capacity
Use a power supply that is greater than the rated input capacity (kVA) of the MxC. If the power is lower than
the rated capacity of the MxC, the device will be unable to run the application properly and a fault will occur.
The input capacity of the MxC, S
CONV
(kVA), can be calculated by the following formula.
S
CONV
= × I
in
× V
in
÷ 1000
(I
in
: MxC Rated input current [A], V
in
: Applicable power line-to-line voltage [V])
„ Connection to Power Supply
The total impedance of the power supply and wiring for the rated current of the MxC is %Z = 10% or more. If
the impedance of the power supply is too large, then power voltage distortion may occur. If the wiring is too
long, then be sure that proper preventative measures such as thick cables or series wiring have been taken to
lower the impedance of wiring.
„ Grounding the power supply
Observe the following precautions when grounding the MxC.
• Because Mxc is designed to run with a 1:1 ratio relative ratio relative to the power supply, it is highly rec-
ommended that the power supply has its own dedicated ground.
• Other devices should be grounded as directed in the specifications for those device.
• Particular care needs to be taken when connecting sensitive electronic equipment (such as OA devices).
Separate ground lines to prevent problems from noise, and install a noise filter.
„ Precaution on Using Peripheral Devices
If installing a noise filter on the power-supply side of the MxC, use a specified noise filter such as a FINEMET
zero-phase reactor.
Model
Required Time to be Ready After Power
is Turned On
Varispeed AC (MxC) Approx. 1.5 seconds *
Varispeed G7/F7 Approx. 0.5 seconds *
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