The Length Of Motor Cable; Cable Length Suggestion For Drive In Full Load; Effect Of Surge Voltages For Motor And Suggestion - Delta C2000 series User Manual

The length of motor cable

1. Cable length suggestion for Drive in full load

a. Non-shielded cables:
For 5.5kW(7.5HP) model and below, max. cable length between the drive and motor is 328ft
(100m). For 7.5kW(10HP) model and above is 656ft (200m).
b. Shielded cables:
For 5.5kW(7.5HP) model and below, max. cable length between the drive and motor is 164ft
(50m). For 7.5kW(10HP) model and above is 328ft (100m).
If cable length is longer than the suggested above, 3-phase load reactor is required.

2. Effect of Surge voltages for motor and suggestion

When motor is driven by an AC motor drive with PWM control, the motor terminals will experience
surge voltages easily due to power transistors operation of AC motor drive and cable capacitance.
When the motor cable is very long (especially for the 460V series), surge voltages may reduce
insulation quality. To prevent this situation, please follow the rules below:
a. Use a motor with enhanced insulation (Please refer to following charts)
b. Connect an output reactor (optional) to the output terminals of the AC motor drive
c. The length of the cable between AC motor drive and motor should be as short as
possible (10 to 20 m or less)
For drive power range≧7.5kW(10HP)
Motor Insulation level
Input 460VAC
Input 230VAC
For drive power range≦5.5kW(7.5HP)
Motor Insulation level
Input 460VAC
Input 230VAC
Chapter 7 Optional AccessoriesC2000 Series
Saddle on both ends
Saddle on one end
Figure 2
1000V 1300V
66 ft (20m) 328 ft (100m)
1312 ft (400m) 1312 ft (400m)
1000V 1300V
66 ft (20m) 165 ft (100m)
328 ft (400m) 328 ft (400m)
7-11
1600V
1312 ft (400m)
1312 ft (400m)
1600V
165 ft (400m)
328 ft (400m)