[CA] [CA11] drive clutch not engaging

[[email protected]]

Installing Evolution Autopilot (ACU-200), and going through the setup, the drive clutch doesn't even try to engage. I can externally engage the clutch, and the helm will move.

Have I missed a setting of some sort?

Drive unit is from my previous autopilot (Cetek-Benmar model "M")

On Edit:
When I put the A/P in "auto", the voltage to the clutch is 0.054V. If I disconnect the clutch and measure the output, it's 13.8v. It appears that the clutch is loading down the system. Would a relay be the solution?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Bob,

Unfortunately, it would not be possible to identify the type of autopilot drive unit is installed based upon the type of third party autopilot which it had been interfaced to. We would also not have typically recommended an ACU-200 for use with any third party drive unit other than an Octopus mechanical stern drive or mechanical helm drive. Should the third party drive unit be compatible with an Evolution autopilot, then an ACU-400 would have typically been recommended. As Evolution autopilot algorithms are based upon a 10-12 second hard over time window, it would first be recommended that rudder be moved fully to one side, that the clutch and motor leads be disconnected from the ACU's, that the clutch leads be connected to an independent source of voltage, and that the motor leads then also be connected to an independent source of voltage to drive the motor to the opposite stops. Should the hard over time be outside of this window, then the drive unit would need to be replaced with a Raymarine drive unit of the appropriate style and capacity for the vessel and its steering system.

If the drive is compatible, then the next step would be to identify the type of drive which is installed (hydraulic linear, mechanical linear, etc.) and mate it to an ACU-400. Should the drive continue to load down the clutch output of the ACU-400, then it may indeed be necessary to install a relay.

[[email protected]]

Upon further testing, I determined that the clutch solenoid measured 1 ohm, but when I activate it, it draws only 1.06 amps. The ACU-200 is supposed to sink 2 amps, so this is somewhat confusing.
Nevertheless, a simple headlight relay seems to have solved the problem.
Hard-over time is somewhere around 20 seconds.
Boat is an O'day 37 (disp. 7 tons).
Rudder reference is not installed.
Have not done sea test yet. . .dockside only.
Type I rotary drive.

[Chuck - Raymarine - Moderator]

Bob,

Please note that the hard over time is well outside of that which the Evolution autopilots are designed to support. Accordingly, should the drive unit not be replaced (Type 1 12V: M81135 recommended for a vessels up to 11,000 kg), then this installation would unfortunately have to be considered unsupported.