Delta CP2000 Series, User Manual

Page: 159 / 868

Chapter 7 Optional Accessories

CP2000
7-50
Motor Cable Length
1. Leakage current to affect the motor and counter measurement
Due to larger parasitic capacitances in longer motor cables, longer cables increase the leakage
current. This can activate the over-current protection and display the incorrect current. In the worst
case, it can damage the drive.
If more than one motor is connected to the AC motor drive, the total motor cable length is the
sum of the cable length from the AC motor drive to each motor. For 460V series AC motor drives,
when an overload relay is installed between the drive and the motor to protect the motor from
overheating, the connecting cable must be shorter than 50m.
However, the overload relay could still malfunction. To prevent this, install an AC output reactor
(optional) to the drive and / or lower the carrier frequency setting (Pr.00-17).
2. Surge voltage to affect the motor and counter measurement
When a PWM signal from an AC motor drive drives the motor, the motor terminals can easily
experience surge voltages (dv/dt) due to IGBT switching 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, follow the rules listed 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 the values in the table below.
The following table list the suggested motor shielded cable length that comply with IEC 60034-17,
which is suitable for the motor with rated voltage under 500 V
AC
, and the insulation level of peak-to-peak
over (including) 1.35 kV
230V
Model
kW HP
Rated current
(Arms)
Without AC output reactor 3% With AC output reactor
Normal
Duty
Light
Duty
Shielded Cable
[meter]
Non-shielded cable
[meter]
Shielded Cable
[meter]
Non-shielded cable
[meter]
007 0.75 1 4.6 5 50 75 75 115
015 1.5 2 5 7.5 50 75 75 115
022 2.2 3 8 10 50 75 75 115
037 3.7 5 11 15 50 75 75 115
040 4 5 17 21 50 75 75 115
055 5.5 7.5 25 31 100 150 150 225
075 7.5 10 33 46 100 150 150 225
150 15 20 49 61 100 150 150 225
185 18.5 25 65 75 100 150 150 225
220 22 30 75 90 100 150 150 225
300 30 40 90 120 100 150 150 225
370 37 50 120 146 100 150 150 225
450 45 60 146 180 150 225 225 325
550 55 75 180 215 150 225 225 325
750 75 100 215 276 150 225 225 325
900 90 125 255 322 150 225 225 325
Table 7-59