ACU 100/EV1 Autopilot Deviation

[ferssini]

Hi,

As I have read from the Installation & Operation Manual, and also here in this Forum, the maximum deviation recommended for the EV1 is 15°.
After almost 6 months of sailing since it was installed, mine is showing 14°, which should be OK, but I am concerned that it is too close to the recommended limit. For my location, the stated deviation should be 8° (True North vs Magnetic North).

Q: In order to get a lower deviation reading, should I move the Sensor Core to another location, or should it be enough if I turn it a few degrees, using the pointing arrow as reference? I believe that the Sensor is now reasonably aligned with the boat's centreline (longitudinal axis) but, as it is mounted parallel to the centreline, it is rather difficult to determine if it is well aligned.

Q: Is it possible to determine the direction of the deviation (E or W) due to a possible misalignement of the instrument?

Thanks in advance for your help.
Best Regards

[Steve - Raymarine - Moderator]

You are talking about two different things. The stated Variation for your location is 8 degrees. That is an understanding of the magnetic variance of your area from magnetic north. The Deviation reported by the autopilot EV-1, is a maximum deviation from ferrous metal or electronic interference around the EV-1 from the complete compass rose, the direction of the interference is not reported when the Deviation is calculated.

That only way to lower the Deviation is to relocate the EV-1 sensor, keeping in mind the location or any ferrous metal or electronic equipment and moving the EV-1 as far away as possible.

[ferssini]

Understood.
Thanks a lot!
Best Regards

[Steve - Raymarine - Moderator]

Anytime, let us know if you have any future questions.

[ferssini]

Hi Steve,

As an update of this post, I am pleased to tell you that I have moved the EV1 Core Sensor to a new location on my sailboat and got a 3° deviation, instead of the previous 14° at the original location. So, as the popular saying states: "location, location, location"!

I have a final question:

Q: the p70 has an option called "aligning compass to GPS"; as I have an MDF connected to the seatalk ng network, should I perform this operation to get the most accurate "heading" reading, or should the EV1 Core Sensor do it by itself while navigating as part of the learning process?

Thanks a lot for your help.
Best Regards

[Steve - Raymarine - Moderator]

The align compass to GPS is mainly for alignment, the Evolution system will dial in the heading while navigating as part of the learning process with your vessel.

[ferssini]

Steve,
As per your kind answer, I understand that it is better to keep the Core Sensor as it is now and let the EV1 continue its automatic learning process. Is that correct?
Rgds

[Steve - Raymarine - Moderator]

Correct.