Table of Contents
Advertisement
Chapter 7 Optional Accessories CFP2000
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
peak-to-peak over (including) 1.35 kV.
Model
VFD007FP4EA-41/-52/
VFD007FP4EA-52S
VFD015FP4EA-41/-52/
VFD015FP4EA-52S
VFD022FP4EA-41/-52/
VFD022FP4EA-52S
VFD037FP4EA-41/-52/
VFD037FP4EA-52S
VFD040FP4EA-41/-52/
VFD040FP4EA-52S
VFD055FP4EA-41/-52/
VFD055FP4EA-52S
VFD075FP4EA-41/-52/
VFD075FP4EA-52S
VFD110FP4EA-41/-52/
VFD110FP4EA-52S
VFD150FP4EA-41/-52/
VFD150FP4EA-52S
VFD185FP4EA-41/-52/
VFD185FP4EA-52S
VFD220FP4EA-41/-52/
VFD220FP4EA-52S
VFD300FP4EA-41/-52/
VFD300FP4EA-52S
VFD370FP4EA-41/-52/
VFD370FP4EA-52S
VFD450FP4EA-41/-52/
VFD450FP4EA-52S
VFD550FP4EA-41/-52/
VFD550FP4EA-52S
VFD750FP4EA-41/-52/
VFD750FP4EA-52S
VFD900FP4EA-41/-52/
VFD900FP4EA-52S
Rated Amps of AC
Reactor (Arms)
kW
HP
Normal
Light
Duty
Duty
0.75
1
1.7
1.5
2
3
2.2
3
4
3.7
5
6
4
5
9
10.5
5.5
7.5
10.5
7.5
10
12
11
15
18
15
20
24
18.5
25
32
22
30
38
30
40
45
37
50
60
45
60
73
55
75
91
110
75
100
110
150
90
125
150
180
Without AC Output Reactor
Shielded
Non-shielded
cable [meter]
cable [meter]
3
4.2
5.5
50
8.5
13
18
24
32
38
100
45
60
73
91
150
7-24
, and the insulation level of
AC
3% With AC Output
Reactor
Shielded
Non-shielded
cable [meter]
cable [meter]
75
75
150
150
225
225
115
225
325
Table 7-19
Advertisement
Table of Contents
