When I operate PAN-A series in the constant current (CC) mode, do I need to turn the VOLTAGE control knob clockwise to the maximum?

If you turn the VOLTAGE control knob clockwise to the maximum, PAN-A series may output the maximum voltage depending on the load condition.
Please set the appropriate output voltage the load can accept.
For the details, read the user’s manual – chapter of Basic Operation – Using as a constant current power supply.