Version 3.05
| Optidrive Eco User Guide |
23
www.invertekdrives.com
4.6. Drive and Motor Connection
The drive inherently produces fast switching of the output voltage (PWM) to the motor compared to the mains supply, for motors
which have been wound for operation with a variable speed drive then there is no preventative measures required, however if the
quality of insulation is unknown then the motor manufacturer should be consulted and preventative measures may be required.
The motor should be connected to the Optidrive U, V, and W terminals using a suitable 3 or 4 core cable. Where a 3 core cable
is used, with the shield operating as an earth conductor, the shield must have a cross sectional area at least equal to the phase
conductors when they are made from the same material. Where a 4 core cable is utilised, the earth conductor must be of at least
equal cross sectional area and manufactured from the same material as the phase conductors.
The motor earth must be connected to one of the Optidrive earth terminals.
For compliance with the European EMC directive, a suitable screened (shielded) cable should be used. Braided or twisted type
screened cable where the screen covers at least 85% of the cable surface area, designed with low impedance to HF signals are
recommended as a minimum. Installation within a suitable steel or copper tube is generally also acceptable.
The cable screen should be terminated at the motor end using an EMC type gland allowing connection to the motor body through
the largest possible surface area.
Where drives are mounted in a steel control panel enclosure, the cable screen may be terminated directly to the control panel
using a suitable EMC clamp or gland, as close to the drive as possible.
Automatic switchgear should not be installed between the drive output and the motor, opening and closing contacts in this circuit whilst
the drive is energised will inevitably reduce the lifetime of the drive and could cause product failure. If an isolator is required to be placed
between the drive and the motor in order to comply with local regulations, the device must not be operated when the drive is running.
4.7. Motor Terminal Box Connections
Most general purpose motors are wound for operation on two supply voltage. This will be indicated on the nameplate of the motor.
The operational voltage is normally selected when installing the motor by selecting either STAR or DELTA connection. STAR always
gives the higher of the two voltage ratings.
Incoming Supply Voltage
Motor Nameplate Voltages
Connection
230
230 / 400
Delta
400 / 460
400 / 690
575
575 / 1000
400
230 / 400
Star
575
330 / 575
4
Elec
trical Installation
