7.5.3 Motor Bearing Currents
All motors installed with AF-650 GP 90 kW or higher power drives should have NDE (Non-Drive End) insulated bearings installed to eliminate circulating bearing
currents. To minimize DE (Drive End) bearing and shaft currents proper grounding of the drive, motor, driven machine, and motor to the driven machine is required.
Standard Mitigation Strategies:
1.
Use an insulated bearing
2.
Apply rigorous installation procedures
-
Ensure the motor and load motor are aligned
-
Strictly follow the EMC Installation guideline
-
Reinforce the PE so the high frequency impedance is lower in the PE than the input power leads
-
Provide a good high frequency connection between the motor and the frequency converter for instance by screened cable which has a 360°
connection in the motor and the frequency converter
-
Make sure that the impedance from frequency converter to building ground is lower that the grounding impedance of the machine. This can
be difficult for pumps
-
Make a direct earth connection between the motor and load motor
3.
Lower the IGBT switching frequency
4.
Modify the inverter waveform, 60° AVM vs. SFAVM
5.
Install a shaft grounding system or use an isolating coupling
6.
Apply conductive lubrication
7.
Use minimum speed settings if possible
8.
Try to ensure the line voltage is balanced to ground. This can be difficult for IT, TT, TN-CS or Grounded leg systems
9.
Use a dU/dt or sinus filter
7.6 Control Cables and Terminals
7.6.1 Access to Control Terminals
All terminals to the control cables are located underneath the terminal cover on the front of the frequency converter. Remove the terminal cover by means of a
screwdriver (see illustration).
130BT304.10
Illustration 7.30: Unit Size 12, 13,23, 24, 33 and 34
130BT334.11
Illustration 7.31: Unit Size 15, 21, 22, 31 and 32
AF-650 GP Design Guide
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Содержание AF-650 GP Series
Страница 5: ...AF 650 GP Design Guide 4 1...
Страница 53: ...AF 650 GP Design Guide 52 4...
Страница 97: ...Please note airflow directions 6 1 5 Mechanical Dimensions AF 650 GP Design Guide 96 6...
Страница 98: ...Please note airflow directions AF 650 GP Design Guide 97 6...
Страница 99: ...Please note airflow directions AF 650 GP Design Guide 98 6...
Страница 100: ...Please note airflow directions AF 650 GP Design Guide 99 6...
Страница 173: ...Max cable length 150 m AF 650 GP Design Guide 172 9...
Страница 179: ...AF 650 GP Design Guide 178 9...