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***Chuck - Raymarine - Moderator***

Should the Motor leads be mated to a specific Motor A/B terminal of the ACU / course computer?

Autopilot drive units feature reversing DC motors. Accordingly, reversing the connection of a drive unit's Motor leads between a power source's positive and negative terminals will simply cause the motor to rotate in direction opposite that which it had previously rotated. Accordingly, during the dockside portion of the autopilot commissioning, should the drive unit move the rudder in the incorrect direction when a +/- 10 heading change is commanded, then one would simply:
- disconnect the motor lead which is presently connected to the ACU / course computer's Motor A terminal and instead connect it to the Motor B terminal; and
- disconnect the motor lead which had been connected to the ACU / course computer's Motor B terminal and instead connect it to the Motor A terminal.

While is possible also to address reversed drive unit motor phasing via the autopilot control head of Evolution or SPX autopilots, updates to the autopilot's software or execution of a Pilot Factory Reset command will revert drive unit motor phasing back to its the default setting, necessitating that one address reversed drive unit motor phasing via the autopilot control head each time that one of these actions take place. Accordingly, it is considered a best installation practice to ensure that reversed motor phasing is addressed in the manner specified within first paragraph of this FAQ.

Unlike other autopilot drive units, the wheel drives are only designed to be installed in one orientation and hence direction may be provided regarding which Motor terminals of the ACU will be used to connect each of the autopilot's motor leads. The wheel drive's brown Motor lead will be connected to the ACU / course computer's Motor A terminal. The wheel drive's blue Motor lead will be connected to the ACU / course computer's Motor B terminal.

RAYFAQ.