Re: [Amel Yacht Owners] Ground Behind Nav Station
toggle quoted messageShow quoted text
I have purchased a silver/silver chloride probe (look on boat zincs dot com) which is used with your multimeter to check "hull potential". It was about $125 U.S. plus shipping, and is the least expensive way to see if you have a current leak.
My understanding is that even if you have some inappropriate connections between battery and bonding systems, you may not have a problem...yet. It may take a fault in some electrical component to get the destructive current leak.
If you check hull potential and find a leak, it would be prudent to stop everything and find the problem.
If hull potential is normal you have more time to sort it all out.
It is recommended that I check hull potential every time I add or replace equipment, tie up to a new dock, change anchorage, and once a month even if nothing has changed. If it shows a problem, investigate further.
I'm still in the process of going through all electrical gear on the boat to check connections. It's a lot of crawling around, but I'm learning where all the wires run and how things work.
Since correcting the problems with the charger and bonding of the CDrive and engine, I don't see any voltage between the batteries (12 or 24V). It will be interesting to see what I find when we're back in the water and I can use my new hull potential monitor.
I'm still learning, so if anyone sees something here that doesn't look right, please chime in.
On Apr 13, 2015, at 8:22 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:
Thank you as always for taking the time. Am I correct in that the Green/Yellow wires should NOT have any connection to the battery neg(-)?
I really wish I understood this better. But no time like the present to learn. The part that makes me scratch my head on this is the Furuno heading sensor (which I am assuming is original)
Yes, please photo the original terminal for me. Thanks again.
With best regards,
Super Maramu 2000
I don't have the answers that you are looking for.
If I were to guess, my guess would be that some electric device has been added to the battery bank and its case connected to the bonding system. For example, when I first moved on the boat, I noticed some green/yellow wires that were purposefully terminated near the SSB and GPS. Each of these devices had a ground lug and it appeared to me that the installer forgot to connect the yellow/green wire. This voice inside my head told me, "don't fix what you do not understand." I left them as they were, while another voice was telling me to connect them. It could be something that simple.
The issue is that many device cases are connected (grounded) to the (-) side of the DC power. In thias situation, when you connect the green/yellow bonding wire to the case, you have also connected the (-) pole of the battery bank to the bonding system.
Hopefully I have given you some places to look.
Also, I looked at that terminal block photo. It appears to me that a lot has been added there. And it appears that most are unlabeled. I would disconnect all of the leads, check your battery bank (+) to the bonding yellow/green and see if that voltage disappeared. If it did, reconnect 1 set +&- at a time to find the device. Each time you connect one, label it. If disconnecting all of them did not locate your problem, still reconnect one at a time and label it. You might consider connecting a multiple fused-block to the original terminal block, then connect each item to its own fuse. Neater and better. Something like this with a negative bus: https://www.bluesea.com/products/5025/ST_Blade_Fuse_Block_-_6_Circuits_with_Negative_Bus_and_Cover
OK, I have filled your available time for a week. If you like, I will take a photo of that terminal block as it came from Amel because I have not added anything. Let me know.