I'm installing autpilot. I have to ground the course computer. Instructions recommend using the ship's ground which would be connected with water. I don't have that so the alternative is to use the negative terminal of the battery. I already have a negative lead going to the computer. Can't I use that also for the ground since it is connected to the negative terminal of the attery?
Grounding X-5 Autopilot
- Thread starter Pat T
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Pat...
After reading the installation instructions a number of times to try to figure out what the "British language" on grounding meant, I finally ran a heavy green ground wire from the Autopilot's grounding post to the negative posts of my house battery bank. System has worked fine ever since.
This is done to create a "logic" ground for all those little "1's and 0's" that make up the digital language of computers. It is not the same as the "power ground" used in other 12 volt systems such as in cars.
After reading the installation instructions a number of times to try to figure out what the "British language" on grounding meant, I finally ran a heavy green ground wire from the Autopilot's grounding post to the negative posts of my house battery bank. System has worked fine ever since.
This is done to create a "logic" ground for all those little "1's and 0's" that make up the digital language of computers. It is not the same as the "power ground" used in other 12 volt systems such as in cars.
As long as the connections are all good, that wire is also connected to the engine ground which is connected to the propeller in the water, unless you've isolated the prop shaft with an un-bonded elastomer coupling..
It would be better to go straight to engine case ground, but with clean connections, the battery neg should be OK..
It would be better to go straight to engine case ground, but with clean connections, the battery neg should be OK..
Thanks guys. Sounds like using the engine case as a ground might be the way to go since it may be the shortest run. Says to use a 4mm wire for this which is equivalent to AWG #6 which seems pretty thick. Now how to I connect that thick wire to the small grounding connector on the computer. It appears I have to use a 1/4 inch slotted crimp on fastener which seems pretty small for a #6 wire don't you think?
Now that I'm at the boat I can see a possible attachment place on a transmission bracket for a ground. Would this also be a good place to attach a ground? I would guess this is dependent on the tranmission being able to carrying current? Not sure what a Hurth transmission case is made of?
The heavy gauge ground wire is to minimize any electical noise interference with the other instruments.
...I just completed the install & commissioning of the X5 on my C30. I ran a #10 ground to the closest house bank battery neg. post. It was about 6' away from the course computer. Everything seems to be working fine. Love that pilot.
Yea, I can't see using #6 wire for ground. I only have about a 12 ft. run to make. Besides, I can't figure how a #6 would connect to the course computer anyway.
There's most likely no difference between #6/10 or even 18 for electrical interference for the lengths discussed. The best would be a flat wide braided strap as it's surface area that's needed for interference mitigation. It would be a separate path other than the power gnd. Wire is usually an impedance to high frequencies. Take the fast rise/fall times of those 1s and 0s and convert to freq. That's where the high freqs come in.
My battery bank's negative wire is bolted to my Yanmar by about 2 feet of 00 AWG wire. The battery negative terminal is about a foot below the Autopilot computer mounting and a shorter run than to the engine itself. Same effective grounding.
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