Selection Of The Motor Cable; Connection Of The Motor - KEB COMBIVERT F6 Instruction Manual

Connection Power Unit
2.7.2

Selection of the motor cable

Correct selection and wiring of the motor cable is very important:
• lower abrasion of the motor bearings by leakage currents
• improved EMC characteristics
• lower symmetrical operating capacities
• less losses by transient currents
Picture
2.7.2
PE
U
PE
W
2.7.3

Connection of the motor

As a standard the connection of the motor must be carried out in accordance with the follow-
ing table:
Connection of the motor
230 V
Delta
Motor connection in star connection
PE
GB - 30
Cross section of a shielded motor cable with tripartited protective earth con-
ductor
It is recommended to use symmetric shielded motor cables at
high motor ratings (>30 kW). At these cables the protective earth
conductor is tripartited and uniformly placed between the phase
V
lines.
A cable without protective earth conductor can be used if the
local regulations allow this. Then this protective earth conductor
PE
must be placed externally. Certain cables accept also the shield-
ing as protective earth conductor.
Pay attention to the data of the cable manufacturer!
230/400 V motor
3
U1 V1 W1
W2 U2 V2
The connecting-up instructions of the motor manufacturer are generally valid !
Inverter switch at the output with a du/dt of approx. 5kV/µs.
Protect motor Voltage peaks that endanger the insulation system at the
against voltage motor can occur especially in case of long motor cables (>
peaks ! 15 m). A motor choke, a du/dt filter or sine-wave filter can be
used to protect the motor.
400 V
Star
Motor connection in delta connection
400/690 V motor
400 V
Delta
3
PE
U1 V1 W1
W2 U2
690 V
Star
V2