Parker LINKnet AC30P, Руководство по установке оборудования

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A-16
Compliance
AC30 series Variable Speed Inverter
Increasing Motor Cable Length
Because cable capacitance and hence conducted emissions increase with motor cable length, conformance to EMC limits is only guaranteed
with the specified AC supply filter option up to a maximum cable length as specified on page A-15.
This maximum cable length can be improved using the specified external input or output filters.
Screened/armored cable has significant capacitance between the conductors and screen, which increases linearly with cable length (typically
200pF/m but varies with cable type and current rating).
Long cable lengths may have the following undesirable effects:
•
Tripping on ‘overcurrent’ as the cable capacitance is charged and discharged at the switching frequency.
•
Producing increased conducted emissions that degrade the performance of the EMC filter due to saturation.
•
Causing RCDs (Residual Current Devices) to trip due to increased high frequency earth current.
•
Producing increased heating inside the EMC ac supply filter from the increased conducted emissions.
•
These effects can be overcome by adding chokes or output filters at the output of the VSD.
Refer to ‘Chapter 6: Associated Equipment – Power Stack’ for AC output choke specifications.
EMC Motor Output Filter
This can help the drive achieve EMC and filter thermal requirements. It also ensures longer motor life by reducing the high voltage slew rate and
overvoltage stresses. Mount the filter as close to the VSD as possible.
Output Contactors
Output contactors can be used, although we recommend that this type of operation is limited to emergency use only or in a system where they
are required to provide a means of electrical isolation.
WARNING
Ensure that the inverter output is fully quenched before opening or closing the output contactor. Failure to do so can result in damage
to the unit.
External AC Supply EMC Filter
When an external AC supply EMC filter is required, mount it as close as possible to the drive.
Refer to ‘Chapter 6: Associated Equipment – Power Stack’ for recommended external EMC filters.
Internal Filter Disconnection
There are separate disconnects for the internal overvoltage suppressors to earth (identified by the label ‘VDR’) and the internal filter capacitors to
earth (identified by the label ‘YCAP’).
DC supplied inverters do not have overvoltage suppressors to earth.
Refer to ‘Chapter 4: Installation – Power Stack’ for details on how to disconnect them from earth.