On a new S-Flex installation, why does the motor run correctly in bypass and incorrectly in AFC?

Issue:
The motor runs forward in bypass but reverse in AFC.

Product Line:
S-Flex

Environment:
S-Flex with BYPASS feature

Cause:
None

Resolution:
In BYPASS mode, the power supply phase rotation passes straight through to the motor.  In AFC mode, the VFD chops the AC power to DC and then creates an independent phase rotation on the Pulse Width Modulation output to the motor.  Therefore, a new installation can initially result in various combinations of forward/reverse motor rotation in BYP/AFC modes.  The Instruction Bulletin provides the preferred method to correct the motor rotation in both BYP and AFC modes.  See the attached file.

Publicerad för:Schneider Electric Sverige