Nidec 5200250 - Page 98

98 Unidrive M/HS Frame 5 to 6 Power Installation Guide
Issue Number: 9
5.1.22 Maximum motor lengths and types
Since capacitance in the motor cable causes loading on the output of the drive, ensure the cable
length does not exceed the values given in Table 5-24.
Use 105 °C (221 °F) (UL 60/75 °C temp rise) PVC-insulated cable with copper conductors having a
suitable voltage rating, for the following power connections:
• AC supply to external EMC filter (when used)
• AC supply (or external EMC filter) to drive
• Drive to motor
• Drive to braking resistor
Table 5-24 Maximum motor cable lengths
• Cable lengths in excess of the specified values may be used only when special techniques are
adopted; refer to the supplier of the drive.
• The default switching frequency is 3 kHz for Open-loop and RFC-A and 6 kHz for RFC-S mode.
The maximum cable length is reduced from that shown in Table 5-24 if high capacitance or reduced
diameter motor cables are used, refer to section 4.9.2 High-capacitance / reduced diameter
cables on page 58
Model
Maximum permissible motor cable length for each of the following switching frequencies
2
kHz
3
kHz
4
kHz
6
kHz
8
kHz
12
kHz
16
kHz
Size 5
200 m (660 ft)
150 m
(490 ft)
100 m
(330 ft)
75 m
(245 ft)
50 m
(165 ft)
37 m
(120 ft)
Size 6