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Bonding and grounding on Maramu


smiles bernard
 

Hello folks

I’m just in the process of replacing the keel bolt bonding strap on my 1985 Maramu.

It’s led to some head scratching re bonding and grounding and the wiring runs on these lovely boats.

SeaLove has a copper ground plate on the skeg. I assume my radar is grounded to this. Perhaps also my furuno weatherfax etc

Can anyone be kind enough to explain where the connection to the ground plate typically surfaces?

Also to check my assumptions re the bonding system setup. . . .
I think all bonding cables run onto a connection in the transom as per the photo attached



It ‘looks’ like this copper plate is glasses into the hull and runs down the transom to surface near the rudder via the two tubes shown on the left in the photo below :


For some reason this surfaces as 2 separate cables that then are both connected to the rudder stock, and hence the anode on the rudder :




Does this bonding setup look about right ?

Slightly confused as to why there are 2 cables here ?


Many thanks in advance

Miles
Maramu 162


karkauai
 

You are seeing the grounding plate)cables for the SSB counterpoise.  The copper strap in the bilge is the keel connection to the bonding system and zincs (assuming it is like the SM) which connects to the zincs via the rudder post.
Kent
SM 243
Kristy

On Feb 22, 2020 4:02 PM, "smiles bernard via Groups.Io" <smilesbernard@...> wrote:

Hello folks

I’m just in the process of replacing the keel bolt bonding strap on my 1985 Maramu.

It’s led to some head scratching re bonding and grounding and the wiring runs on these lovely boats.

SeaLove has a copper ground plate on the skeg. I assume my radar is grounded to this. Perhaps also my furuno weatherfax etc

Can anyone be kind enough to explain where the connection to the ground plate typically surfaces?

Also to check my assumptions re the bonding system setup. . . .
I think  all bonding cables run onto a connection in the transom as per the photo attached



It ‘looks’ like this copper plate is glasses into the hull and runs down the transom to surface near the rudder via the two tubes shown on the left in the photo below :


For some reason this surfaces as 2 separate cables that then are both connected to the rudder stock, and hence the anode on the rudder :




Does  this bonding setup look about right ?

Slightly confused as to why there are 2 cables here ?


Many thanks in advance

Miles
Maramu 162





smiles bernard
 

Thanks for your reply Kent
Hmmm confused still.
Which bit in the photos is the ssb grounding plate connection?

I have 0 ohms when I test between the  copper strap In the transom locker and the rudder post connectors so assumed these are all bonding ?

Thanks again

Miles


On 22 Feb 2020, at 21:21, karkauai via Groups.Io <karkauai@...> wrote:


You are seeing the grounding plate)cables for the SSB counterpoise.  The copper strap in the bilge is the keel connection to the bonding system and zincs (assuming it is like the SM) which connects to the zincs via the rudder post.
Kent
SM 243
Kristy

On Feb 22, 2020 4:02 PM, "smiles bernard via Groups.Io" <smilesbernard@...> wrote:

Hello folks

I’m just in the process of replacing the keel bolt bonding strap on my 1985 Maramu.

It’s led to some head scratching re bonding and grounding and the wiring runs on these lovely boats.

SeaLove has a copper ground plate on the skeg. I assume my radar is grounded to this. Perhaps also my furuno weatherfax etc

Can anyone be kind enough to explain where the connection to the ground plate typically surfaces?

Also to check my assumptions re the bonding system setup. . . .
I think  all bonding cables run onto a connection in the transom as per the photo attached



It ‘looks’ like this copper plate is glasses into the hull and runs down the transom to surface near the rudder via the two tubes shown on the left in the photo below :


For some reason this surfaces as 2 separate cables that then are both connected to the rudder stock, and hence the anode on the rudder :




Does  this bonding setup look about right ?

Slightly confused as to why there are 2 cables here ?


Many thanks in advance

Miles
Maramu 162





Alan Leslie
 

Hi  Miles,

If your boat is like ours, which I assume it is......

On the skeg is a sintered bronze plate which is the ground for the SSB radio.
The wire from that should end up in the nav station area and only be connected to the ground connection on the SSB..
This cable often has BLU written on it.
This cable is only connected to the bonding system if there is no SSB.
If you have an SSB connected to this cable, there should not be a connection from this cable to the bonding system.

The bonding system is all the wires from metal items in connection with seawater connected together and eventually connected to the rudder shaft which is connected to the anodes on the rudder.

So if you don't have an SSB, it seems correct.
If you do, it isn't.

Cheers
Alan


James Lochhead
 

Our ground for the SSB is connected to the tuner that is located as far aft on the starboard side of the boat as you can go.  I think we have had some modifications to our boat in this area but ours sits behind a removable panel.


--

James
Maramu #147 (1984)


Matt Salatino
 

The SSB radio transmitter ground is different from the antenna tuner ground. They should not be in common.

~~~⛵️~~~Matt

On Feb 22, 2020, at 8:10 PM, James Lochhead <j_lochhead@...> wrote:

Our ground for the SSB is connected to the tuner that is located as far aft on the starboard side of the boat as you can go.  I think we have had some modifications to our boat in this area but ours sits behind a removable panel.


--

James
Maramu #147 (1984)


Alan Leslie
 

Hi Matt,

I don't think that's right.
Our ICOM setup, setup according to the installation instructions, has a heavy green yellow/wire from the SSB ground connection to the AT130 tuner.
Then there is a heavy green/yellow wire from the AT130 tuner to the bolt connection in the lazarette which has copper tape connecting that bolt to the sintered bronze plates on the skeg.
If you don't connect it like this , where does the ground for the SSB transmitter go? ... certainly NOT to the bonding system.
In our ICOM SSB, the transmitter ground is internally connected to the 12V negative supply line, hence the need for an isolated power supply so that there is no connection between ground and 24V negative, which would compromise the bonding system via the seawater path between the sintered bronze plate and the anodes.

Cheers
Alan
Elyse SM437


 

Alan,

Agree. 

Best,

CW Bill Rouse 
Amel Owners Yacht School
+1 832-380-4970 | brouse@...
720 Winnie, Galveston Island, Texas 77550 
www.AmelOwnersYachtSchool.com 
Yacht School Calendar: www.preparetocastoff.blogspot.com/p/calendar.html


   


On Sun, Feb 23, 2020, 2:31 AM Alan Leslie <s.v.elyse@...> wrote:
Hi Matt,

I don't think that's right.
Our ICOM setup, setup according to the installation instructions, has a heavy green yellow/wire from the SSB ground connection to the AT130 tuner.
Then there is a heavy green/yellow wire from the AT130 tuner to the bolt connection in the lazarette which has copper tape connecting that bolt to the sintered bronze plates on the skeg.
If you don't connect it like this , where does the ground for the SSB transmitter go? ... certainly NOT to the bonding system.
In our ICOM SSB, the transmitter ground is internally connected to the 12V negative supply line, hence the need for an isolated power supply so that there is no connection between ground and 24V negative, which would compromise the bonding system via the seawater path between the sintered bronze plate and the anodes.

Cheers
Alan
Elyse SM437