Delta VFD-ED Series User Manual

Chapter 6 Optional Accessories | VFD-ED
6-47
The motor cable length
 Required cable length when the motor drive is at full load.
1. Non-shielded cable: For 5.5 kW (7.5 HP) and below models, the maximum cable length is 100 m
(328 ft). For 7.5 kW (10 HP) and above models, the maximum cable length is 200 m (656 ft)
2. Shielded cable: For 5.5 kW (7.5 HP) and below models, the maximum cable length is 50 m (165
ft). For 7.5 kW (10 HP) models, the maximum cable length is 100 m (328 ft).
3. To be compatible with the European Standards EN12015 & EN12016, follow one of the following
in addition to the precautions on page 6-45:
(1) Use shielded cables
(2) The motor cable must be shorter than 2 m (6 ft).
If the cable length is longer than the recommended lengths above, install an output reactor.
NOTE:
1. If the cable length is too long, the stray capacitance between cables increases and may cause
leakage current. In this case, It activates the over-current protection, increases leakage current,
or may affect the current display. The worst case is that it may damage the AC motor drive.
2. 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.
3. For the 460V series AC motor drive, when you install an overload thermal relay between the drive
and the motor to protect the motor from overheating, the connecting cable must be shorter than
50 m; however, an overload thermal relay malfunction may still occur. To prevent the malfunction,
install an output reactor (optional) to the drive or lower the carrier frequency setting (Pr.00-12).
 Consequence of the surge voltages on the motor
When a motor is driven by a PWM-type AC motor drive, the motor terminals experience surge
voltages due to component conversion of AC motor drive and cable capacitance. When the motor
cable is very long (especially for the 460V series), surge voltages may damage the insulation. To
prevent this, follow these rules:
1. Use a motor with enhanced insulation (refer to the tables below).
2. Reduce the cable length between the AC motor drive and motor to suggested values.
3. Connect an output reactor (optional) to the output terminals of the AC motor drive.
For 7.5 kW (10 HP) and higher models:
Insulation level of motor
1000V
1300V
1600V
460 V
AC
input voltage
20 m (66 ft)
100 m (328 ft)
400 m (1312 ft)
230 V
AC
input voltage
400 m (1312 ft)
400 m (1312 ft)
400 m (1312 ft)
Table 6-40
For 5.5 kW (7.5 HP) and lower models:
Insulation level of motor
1000V
1300V
1600V
460 V
AC
input voltage
20 m (66 ft)
50 m (165 ft)
50 m (165 ft)
230 V
AC
input voltage
100 m (328 ft)
100 m (328 ft)
100 m (328 ft)
Table 6-41

Delta VFD-ED Series Specifications

General

Brand	Delta
Model	VFD-ED Series
Category	DC Drives
Language	English