Yaskawa iQpump Drive User Manual - Manual (Page 39)

2.2 Wiring Main Circuit Terminals
YASKAWA TM.iQp.01 iQpump Drive User Manual 39
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Cable Length Between iQpump Drive and Motor
The iQpump should be installed as close as possible to the motor to minimize the length of load side power cable needed between the
iQpump drive and the motor.
If the cable between the iQpump drive and the motor is long, the high-frequency leakage current will increase, causing the iQpump drive
output current to increase as well. This may affect peripheral devices. To prevent this, reduce the cable length whenever possible, or if
necessary, adjust the carrier frequency (set in C6-02) as shown in Table 2.6 .
The line side power cables, load side power cables and the control wiring should all be run in a separate conduit. Careful attention to this
recommended design practice will avoid many potential motor and iQpump drive related problems.
Table 2.6 Motor Cable Length vs. Carrier Frequency (C6-02)
(See the limitations on carrier frequency, based on iQpump drive capacity and model number in Appendix B ).
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Ground Wiring
Observe the following precautions when connecting the ground wire:
1. 208-240 VAC iQpump drives should have a ground connection with resistance of less than 100 Ω.
2. 480 VAC iQpump drives should have a ground connection with resistance of less than 10 Ω.
3. Do not share the ground wire with other devices, such as motors or large-current electrical equipment.
4. Always use a ground wire that complies with technical standards on electrical equipment and minimize the length of the ground wire.
Leakage current flows through the iQpump drive. Therefore, if the distance between the ground rod and the ground terminal is too
long, potential on the ground terminal of the iQpump drive will become unstable.
5. When using more than one iQpump drive, be careful not to loop the ground wire. See Figure 2.4 .
Figure 2.2 Ground Wiring Examples
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Control Circuit Ground Terminals
The removable iQpump drive control terminal card provides two ground terminals (marked TB3 and TB4) to accept the control wire
shield connection. The control wire shield should be connected on this end only, the opposite end should be isolated with electrical tape.
Motor Cable Length 328ft. (100m) maximum More than 328ft. (100m)
Carrier Frequency 10kHz maximum 5kHz maximum
IMPORTANT Grounding of the iQpump enclosure and motor is required for proper system operation.
NO
OK
OK NOT OK