Chapter 3 - Power Connections Note! To avoid interfering with control signals, route the control wiring away from the power wiring. Avoid long runs of control wiring parallel with power wiring. Input Power Wiring The ACS 300 is suitable for use on a circuit capable of deliv- ering not more than 65,000 RMS symmetrical amperes at 240 or 480 volts maximum for the 200 - 240 volt or 380 - 480 volt models respectively. Caution! The maximum permissible number of DC bus chargings per minute is four. This has to be taken in consideration when using an input power contactor. Motor Wiring The ACS 300 provides solid-state motor overload protec- tion.
Motor thermal protection is activated using the TEMP LIM parameter. If this feature is not used, the motor con- nected to the ACS 300 requires overload protection in accordance with the National Electric Code (U.S.A). The rapid voltage changes cause capacitive current in the motor cable. This current increases with the switching fre- quency and motor cable length. This phenomenon can cause substantially higher current measured by the ACS 300 than the actual motor current, and can cause over- current tripping. Do not exceed 300 ft. motor cable length. The capacitive current can be reduced by installing an out- put choke.
If the motor cable length exceeds 300 ft., please contact your local distributor or ABB office. 16 ACS 300 User’s Manual