Delta Electronics AC Motor Drive VFD-EL - Manual (Page 27)

Chapter 2 Installation and Wiring|
2-6 Revision August 2008, 2ELE, V1.02
D. PNP mode with external power
Sw1
Factory
setting
NPN
PNP
24
Vdc -
+
CAUTION!
1. The wiring of main circuit and control circuit should be separated to prevent erroneous actions.
2. Please use shield wire for the control wiring and not to expose the peeled-off net in front of the
terminal.
3. Please use the shield wire or tube for the power wiring and ground the two ends of the shield
wire or tube.
4. Damaged insulation of wiring may cause personal injury or damage to circuits/equipment if it
comes in contact with high voltage.
5. The AC motor drive, motor and wiring may cause interference. To prevent the equipment
damage, please take care of the erroneous actions of the surrounding sensors and the
equipment.
6. When the AC drive output terminals U/T1, V/T2, and W/T3 are connected to the motor terminals
U/T1, V/T2, and W/T3, respectively. To permanently reverse the direction of motor rotation,
switch over any of the two motor leads.
7. With long motor cables, high capacitive switching current peaks can cause over-current, high
leakage current or lower current readout accuracy. To prevent this, the motor cable should be
less than 20m for 3.7kW models and below. And the cable should be less than 50m for 5.5kW
models and above. For longer motor cables use an AC output reactor.
8. The AC motor drive, electric welding machine and the greater horsepower motor should be
grounded separately.
9. Use ground leads that comply with local regulations and keep them as short as possible.
10. No brake resistor is built in the VFD-EL series, it can install brake resistor for those occasions
that use higher load inertia or frequent start/stop. Refer to Appendix B for details.
11. Multiple VFD-EL units can be installed in one location. All the units should be grounded directly
to a common ground terminal, as shown in the figure below. Ensure there are no ground
loops.