Delta C2000 Series User Manual page 144

Motor Cable Length
1. Leakage current to affect the motor and counter measurement
If the cable length is too long, the parasitic capacitance between cables will enlarge and may
increase leakage current. It will activate the protection of over current, and increased leakage current
will not ensure the correction of current value in display. The worst case is that AC motor drive may
damage.
If more than one motor is connected to the AC motor drive, the total wiring length is the sum of
the wiring length from AC motor drive to each motor.
For the 460V series AC motor drive, when an overload relay is installed between the drive and
the motor to protect motor from overheating, the connecting cable must be shorter than 50m. However,
an overload relay malfunction may still occur. To prevent the malfunction, install an output reactor
(optional) to the drive or lower the carrier frequency setting (Pr. 00-17).
2. Surge voltage to affect the motor and counter measurement
When motor is driven by a PWM signal of AC motor drive, the motor terminals will experience
surge voltages (dv/dt) easily due to power transistors conversion of AC motor drive and cable
capacitance. When the motor cable is very long (especially for the 460V series), surge voltages (dv/dt)
may reduce insulation quality. To prevent this situation, please follow the rules below:
a. Use a motor with enhanced insulation
b. Connect an output reactor (optional) to the output terminals of the AC motor drive
c. Reduce the motor cable length to suggested value
The suggested motor shielded cable length in the following table complies with IEC 60034-17,
which is suitable for the motor with rated voltage under 500 VAC, and the insulation level of
peak-to-peak over (including) 1.35kV
230V Model
VFD007C23A
VFD015C23A
VFD022C23A
VFD037C23A
VFD055C23A
VFD075C23A
VFD110C23A
VFD150C23A
VFD185C23A
VFD220C23A
VFD300C23A/E
VFD370C23A/E
VFD450C23A/E
VFD550C23A/E
VFD750C23A/E
VFD900C23A/E
Without AC reactor
Rated current
Shielded Cable
(ND) (Arms)
[meter]
5 50
8 50
11 50
17 50
25 50
33 100
49 100
65 100
75 100
90 100
120 100
146 100
180 150
215 150
255 150
346 150
Chapter 7 Optional AccessoriesC2000
Non-shielded
cable [meter]
75
75
75
75
75
150
150
150
150
150
150
150
225
225
225
225
7-37
With AC reactor
Shielded Cable Non-shielded
[meter] cable [meter]
75 115
75 115
75 115
75 115
75 115
150 225
150 225
150 225
150 225
150 225
150 225
150 225
225 325
225 325
225 325
225 325
Table 7-45