Motor Connection - GE AF-650 GP Design Manual

7.1.3 Motor Connection

NB!
Use a screened/armoured motor cable to comply with EMC emission specifications. For more information, see EMC Test Results.
See section General Specifications for correct dimensioning of motor cable cross-section and length.
Screening of cables: Avoid installation with twisted screen ends (pigtails). If it is necessary to break the screen to install a motor isolator or motor contactor, the
screen must be continued at the lowest possible HF impedance.
Connect the motor cable screen to both the decoupling plate of the frequency converter and to the metal housing of the motor.
Make the screen connections with the largest possible surface area (cable clamp). This is done by using the supplied installation devices in the frequency converter.
If it is necessary to split the screen to install a motor isolator or motor relay, the screen must be continued with the lowest possible HF impedance.
Cable-length and cross-section: The frequency converter has been tested with a given length of cable and a given cross-section of that cable. If the cross-section
is increased, the cable capacitance - and thus the leakage current - may increase, and the cable length must be reduced correspondingly. Keep the motor cable
as short as possible to reduce the noise level and leakage currents.
Switching frequency: When frequency converters are used together with Sine-wave filters to reduce the acoustic noise from a motor, the switching frequency
must be set according to the Sine-wave filter instruction in par. F-26 Motor Noise (Carrier Freq).
1. Fasten decoupling plate to the bottom of the frequency converter with screws and washers from the accessory bag.
2. Attach motor cable to terminals 96 (U), 97 (V), 98 (W).
3. Connect to earth connection (terminal 99) on decoupling plate with screws from the accessory bag.
4. Insert plug connectors 96 (U), 97 (V), 98 (W) (up to 7.5 kW) and motor cable to terminals labelled MOTOR.
5. Fasten screened cable to decoupling plate with screws and washers from the accessory bag.
All types of three-phase asynchronous standard motors can be connected to the frequency converter. Normally, small motors are star-connected (230/400 V, Y).
Large motors are normally delta-connected (400/690 V, Δ). Refer to the motor name plate for correct connection mode and voltage.
Illustration 7.7: Motor connection for units sizes 12 and 13 IP20
Open Chassis drive types (230V to 5HP, 460V/575V to 10HP)
Illustration 7.8: Motor connection for unit size 15 Nema 12 or
Nema 4 drive types (230V to 5HP, 460V/575V to 10HP)
AF-650 GP Design Guide
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