24V+ Isolated Ground Leak


Paul Stascavage
 

Almost since purchasing our boat, we had a small negative leak that was indicated by the Masse Light.  The electrician in Martinique could not locate the source easily, but said that it was very small and to just keep an eye on the zincs.

Although I tried located the source of this myself many times by disconnecting individual bonding wires, I was never able to locate it.  However, our zincs would get us through 2 years of service with what I considered normal loss (about 30 - 40%) so it didn’t worry me much.

A few months ago, the Masse Light stopped illuminating and I thought maybe something may have fixed itself (wouldn’t that be great?).  But a few weeks ago, when I dove on the zincs, I noticed they had excessive loss and they are slightly less than a year old.

This morning I got out my volt meter, and we do still have a slight negative leak of about 0.009 volts when connecting the voltmeter to the negative post on the battery bank and the bonding wire on the rudder post, but when I checked the positive side, there was a full 25 volts leak indicated!

We recently had our alternator rebuilt so I disconcerted that and found no difference.  I also recently changed the switches on the windless, so I am going to disconnect those and check there as well.  We also had a new VHF radio installed and I will check that, but as that is 12 volts I don’t think that will be it.

I am definitely not electrically proficient, but what boggles me is that when I turn off the battery bank switches, I still show the leakage when testing from the bank.  How is it that with the battery bank isolated, I could still have current going to the bonding system?  What am I missing here?

Any insight and suggestions regarding where I should logically begin my search would be greatly appreciated. I am currently most uncomfortable with that kind of voltage in the bonding system.

Thank you in advance for any and all replies.

All the best,

Paul Stascavage
SM #466 - s/v Rita Kathryn
Currently Exploring City Island, NY


www.RitaKathryn.com


Bill Hall
 

How old is the battery disconnect switch or is it corroded internally?

On Mon, Sep 6, 2021 at 11:40 AM Paul Stascavage via groups.io <pstas2003=yahoo.com@groups.io> wrote:
Almost since purchasing our boat, we had a small negative leak that was indicated by the Masse Light.  The electrician in Martinique could not locate the source easily, but said that it was very small and to just keep an eye on the zincs.

Although I tried located the source of this myself many times by disconnecting individual bonding wires, I was never able to locate it.  However, our zincs would get us through 2 years of service with what I considered normal loss (about 30 - 40%) so it didn’t worry me much.

A few months ago, the Masse Light stopped illuminating and I thought maybe something may have fixed itself (wouldn’t that be great?).  But a few weeks ago, when I dove on the zincs, I noticed they had excessive loss and they are slightly less than a year old.

This morning I got out my volt meter, and we do still have a slight negative leak of about 0.009 volts when connecting the voltmeter to the negative post on the battery bank and the bonding wire on the rudder post, but when I checked the positive side, there was a full 25 volts leak indicated!

We recently had our alternator rebuilt so I disconcerted that and found no difference.  I also recently changed the switches on the windless, so I am going to disconnect those and check there as well.  We also had a new VHF radio installed and I will check that, but as that is 12 volts I don’t think that will be it.

I am definitely not electrically proficient, but what boggles me is that when I turn off the battery bank switches, I still show the leakage when testing from the bank.  How is it that with the battery bank isolated, I could still have current going to the bonding system?  What am I missing here?

Any insight and suggestions regarding where I should logically begin my search would be greatly appreciated. I am currently most uncomfortable with that kind of voltage in the bonding system.

Thank you in advance for any and all replies.

All the best,

Paul Stascavage
SM #466 - s/v Rita Kathryn
Currently Exploring City Island, NY


www.RitaKathryn.com


 


Paul,

There is a 24-volt wiring bus behind the wood panel directly above the nav tabletop labeled 24-volt Permanent. This is hot when the switches are off. The only thing connected to that bus should be the 24-12v step-down transformer that powers the chain counter, the AM/FM Radio, and the 24v plugs at the nav station.

Locate this wiring bus. Is there anything connected to it other than the step-down transformer?

Sorry I do not have a better photo...this piece of a photo is all I could find, and note the extra red wire:
image.png

image.png
CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Mon, Sep 6, 2021 at 1:43 PM Bill Hall <billhall95688@...> wrote:
How old is the battery disconnect switch or is it corroded internally?

On Mon, Sep 6, 2021 at 11:40 AM Paul Stascavage via groups.io <pstas2003=yahoo.com@groups.io> wrote:
Almost since purchasing our boat, we had a small negative leak that was indicated by the Masse Light.  The electrician in Martinique could not locate the source easily, but said that it was very small and to just keep an eye on the zincs.

Although I tried located the source of this myself many times by disconnecting individual bonding wires, I was never able to locate it.  However, our zincs would get us through 2 years of service with what I considered normal loss (about 30 - 40%) so it didn’t worry me much.

A few months ago, the Masse Light stopped illuminating and I thought maybe something may have fixed itself (wouldn’t that be great?).  But a few weeks ago, when I dove on the zincs, I noticed they had excessive loss and they are slightly less than a year old.

This morning I got out my volt meter, and we do still have a slight negative leak of about 0.009 volts when connecting the voltmeter to the negative post on the battery bank and the bonding wire on the rudder post, but when I checked the positive side, there was a full 25 volts leak indicated!

We recently had our alternator rebuilt so I disconcerted that and found no difference.  I also recently changed the switches on the windless, so I am going to disconnect those and check there as well.  We also had a new VHF radio installed and I will check that, but as that is 12 volts I don’t think that will be it.

I am definitely not electrically proficient, but what boggles me is that when I turn off the battery bank switches, I still show the leakage when testing from the bank.  How is it that with the battery bank isolated, I could still have current going to the bonding system?  What am I missing here?

Any insight and suggestions regarding where I should logically begin my search would be greatly appreciated. I am currently most uncomfortable with that kind of voltage in the bonding system.

Thank you in advance for any and all replies.

All the best,

Paul Stascavage
SM #466 - s/v Rita Kathryn
Currently Exploring City Island, NY


www.RitaKathryn.com


John Clark
 

Hi Paul and Bill,
   Am I wrong in thinking that the voltage readings are correct?   Amperage through the bonding system would be a problem.  

My SM 37, has had varying anode lifetimes.  Marinas and shore power shorten life,  I am currently moored and have been working a job in St Thomas for a year and a half. Before that boat parked in Brunswick GA with no shore power.   Cumulative four days in marina in STT and 2018 zincs look good to me.  A few years ago we spent a good amount of time in Le Marin at the dock…zincs did not like that.

Another place to check is the rigging.  My friend on SM24 had a sudden outbreak of rust trails from the rigging mounts.  He had 24v on the rig from a worn cable.  I had a similar experience with a previous owner installed 24v outlet on the main mast that corroded.

Boats….always something.  


  

On Mon, Sep 6, 2021 at 3:57 PM CW Bill Rouse <brouse@...> wrote:

Paul,

There is a 24-volt wiring bus behind the wood panel directly above the nav tabletop labeled 24-volt Permanent. This is hot when the switches are off. The only thing connected to that bus should be the 24-12v step-down transformer that powers the chain counter, the AM/FM Radio, and the 24v plugs at the nav station.

Locate this wiring bus. Is there anything connected to it other than the step-down transformer?

Sorry I do not have a better photo...this piece of a photo is all I could find, and note the extra red wire:
image.png

image.png

On Mon, Sep 6, 2021 at 1:43 PM Bill Hall <billhall95688@...> wrote:
How old is the battery disconnect switch or is it corroded internally?

On Mon, Sep 6, 2021 at 11:40 AM Paul Stascavage via groups.io <pstas2003=yahoo.com@groups.io> wrote:
Almost since purchasing our boat, we had a small negative leak that was indicated by the Masse Light.  The electrician in Martinique could not locate the source easily, but said that it was very small and to just keep an eye on the zincs.

Although I tried located the source of this myself many times by disconnecting individual bonding wires, I was never able to locate it.  However, our zincs would get us through 2 years of service with what I considered normal loss (about 30 - 40%) so it didn’t worry me much.

A few months ago, the Masse Light stopped illuminating and I thought maybe something may have fixed itself (wouldn’t that be great?).  But a few weeks ago, when I dove on the zincs, I noticed they had excessive loss and they are slightly less than a year old.

This morning I got out my volt meter, and we do still have a slight negative leak of about 0.009 volts when connecting the voltmeter to the negative post on the battery bank and the bonding wire on the rudder post, but when I checked the positive side, there was a full 25 volts leak indicated!

We recently had our alternator rebuilt so I disconcerted that and found no difference.  I also recently changed the switches on the windless, so I am going to disconnect those and check there as well.  We also had a new VHF radio installed and I will check that, but as that is 12 volts I don’t think that will be it.

I am definitely not electrically proficient, but what boggles me is that when I turn off the battery bank switches, I still show the leakage when testing from the bank.  How is it that with the battery bank isolated, I could still have current going to the bonding system?  What am I missing here?

Any insight and suggestions regarding where I should logically begin my search would be greatly appreciated. I am currently most uncomfortable with that kind of voltage in the bonding system.

Thank you in advance for any and all replies.

All the best,

Paul Stascavage
SM #466 - s/v Rita Kathryn
Currently Exploring City Island, NY


www.RitaKathryn.com


Mark McGovern
 

Paul,

Bill beat me to it.  As a first check, I would turn off the switch on the Sailor 24v to 12v Step Down Transformer and see if the Masse light still illuminates when you test it.  If it does not, you know that it's something that is being powered by that transformer causing the leak.  As Bill said, there are only a few things that should be powered by that transformer so it should be pretty easy to trace down.

Here's a slightly better pics that might help you locate it:




--
Mark McGovern
SM #440 Cara
Belfast, ME USA


Paul Stascavage
 

Bill Hall,

The switches are original but they are working just fine.  I believe Bill R’s and Mark’s explanation regarding the ‘permanent circuit’ explains why I was still seeing the leak with the switches off, but I appreciate your thoughts.


Hello John,

My rudimentary understanding is where there is voltage there is current.

After I get this rectified, I am going to check and make sure there is no issue with the rigging.  I appreciate the suggestion.


Bill R and Mark,

There are two wires on the negative post of the ‘permanent’ bus but I have not traced them yet.  With your information, I was able to narrow the leak down to the instrument circuit.  With the instrument circuit breaker off, the positive leak goes away.  I will do some more investigating tomorrow and report back when I figure things out further or ask for more assistance if I hit a road block.

My sincere thanks to you both for your help.  I will sleep much better tonight knowing the leak has been temporarily removed.

All the best,

Paul Stascavage
SM #466 - s/v Rita Kathryn
Currently Exploring City Island, NY

www.RitaKathryn.com


Bill Hall
 

Interesting that there would be a permanent on circuit with a transformer.   Would tend to make one kind of crazy

On Mon, Sep 6, 2021 at 7:44 PM Paul Stascavage via groups.io <pstas2003=yahoo.com@groups.io> wrote:
Bill Hall,

The switches are original but they are working just fine.  I believe Bill R’s and Mark’s explanation regarding the ‘permanent circuit’ explains why I was still seeing the leak with the switches off, but I appreciate your thoughts.


Hello John,

My rudimentary understanding is where there is voltage there is current.

After I get this rectified, I am going to check and make sure there is no issue with the rigging.  I appreciate the suggestion.


Bill R and Mark,

There are two wires on the negative post of the ‘permanent’ bus but I have not traced them yet.  With your information, I was able to narrow the leak down to the instrument circuit.  With the instrument circuit breaker off, the positive leak goes away.  I will do some more investigating tomorrow and report back when I figure things out further or ask for more assistance if I hit a road block.

My sincere thanks to you both for your help.  I will sleep much better tonight knowing the leak has been temporarily removed.

All the best,

Paul Stascavage
SM #466 - s/v Rita Kathryn
Currently Exploring City Island, NY

www.RitaKathryn.com


 

Paul,

I bet some "certified electronic technician" was aboard and did something like "grounding and instrument." 

I have seen this more than once. And it is usually because someone is adding some device to the nav station.

Please send me a photo of the 24v Permanent Bus.

Bill


CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Mon, Sep 6, 2021 at 9:47 PM Bill Hall <billhall95688@...> wrote:
Interesting that there would be a permanent on circuit with a transformer.   Would tend to make one kind of crazy

On Mon, Sep 6, 2021 at 7:44 PM Paul Stascavage via groups.io <pstas2003=yahoo.com@groups.io> wrote:
Bill Hall,

The switches are original but they are working just fine.  I believe Bill R’s and Mark’s explanation regarding the ‘permanent circuit’ explains why I was still seeing the leak with the switches off, but I appreciate your thoughts.


Hello John,

My rudimentary understanding is where there is voltage there is current.

After I get this rectified, I am going to check and make sure there is no issue with the rigging.  I appreciate the suggestion.


Bill R and Mark,

There are two wires on the negative post of the ‘permanent’ bus but I have not traced them yet.  With your information, I was able to narrow the leak down to the instrument circuit.  With the instrument circuit breaker off, the positive leak goes away.  I will do some more investigating tomorrow and report back when I figure things out further or ask for more assistance if I hit a road block.

My sincere thanks to you both for your help.  I will sleep much better tonight knowing the leak has been temporarily removed.

All the best,

Paul Stascavage
SM #466 - s/v Rita Kathryn
Currently Exploring City Island, NY

www.RitaKathryn.com


Paul Stascavage
 

Good morning Bill,

I did have a certified electrician aboard a few months back, but all he did was install a new vhf antenna, cable, and vhf unit. I was with him the whole time and am certain that he didn’t install this wire on the negative side of the permanent bus (photo attached). I removed that wire and still have the short with the navigation breaker on  


I also disconnected the vhf unit including the antenna and I still have the short with the navigation breaker on. 

I’m not sure where to logically start next. Any suggestions would be appreciated. 


All the best,

Paul


 

Paul,

Thanks for the photo, but I cannot see the wires at the top of the photo.

If I remember correctly, the wires at the top of this 24v Permanent BUS are from the battery bank and the wires at the bottom should only be 2 wires, 1 positive and 1 negative which are connected to the Permanent 24v to 12v converter.

The two extra wires (darker blue and black) on the left (negative side of the BUS are connecting whatever device they are connected to directly to the 24 negative BUS of the battery bank and bypassing the main battery switch. Start there and disconnect those two wires, then see what turns off. There are several things wrong with these extra wires including the missing opposing positive wire connection. 

When you get a chance, please take another photo.

Everyone else reading this, please don't make new connections to the battery bank without understanding the right way to do it and the pitfalls of doing it wrong. Also, do not allow a technician to use this BUS for any connection...none, nada!


Bill


CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Tue, Sep 7, 2021 at 8:42 AM Paul Stascavage via groups.io <pstas2003=yahoo.com@groups.io> wrote:

Good morning Bill,

I did have a certified electrician aboard a few months back, but all he did was install a new vhf antenna, cable, and vhf unit. I was with him the whole time and am certain that he didn’t install this wire on the negative side of the permanent bus (photo attached). I removed that wire and still have the short with the navigation breaker on  


I also disconnected the vhf unit including the antenna and I still have the short with the navigation breaker on. 

I’m not sure where to logically start next. Any suggestions would be appreciated. 


All the best,

Paul


Mark McGovern
 

Paul,

No problem. Glad I could help you narrow it down.

I want to correct this statement you made to John: "where there is voltage there is current"

It is possible to have voltage without current flow.  However, you cannot have current flow without voltage.  Voltage means there is the "potential" to have current flow.  Think of a battery.  If you measure the voltage across the positive and negative terminals with a multimeter, you will see voltage between those two points.  Therefore, there is the "potential" to have current flow between them.  However, there is no current flow because the circuit is not complete.  If you were to put a wire between the terminals, you would complete the circuit and then you will have current flowing in the wire (don't try this part with a 100aH lead acid battery!) 

Therefore, if you measure the voltage between the 24v house bank (+) and the Yellow/Green bonding wire you will see a voltage reading that is very close to your house bank voltage (24-28v).  If you measure voltage between the 24v house bank (-) and the Yellow/Green bonding wire with a really good multimeter you might also see a very small voltage potential (probably millivolts or zero).

Here's my understanding of how the "Masse" leak detector works.  The Masse + and Masse - tester puts an LED light bulb in a switched circuit between 24v (+)  or 24v (-) and the Yellow/Green bonding wire.  When you close the switch it completes half the circuit.  If there are no connections between 24v (+)  or 24v (-) and the Yellow/Green bonding wire, nothing happens.  However, if somewhere on the boat you have a connection between 24v (+) or 24v (-) and the Yellow/Green bonding wire that completes the OTHER half of the circuit.  Therefore, current will flow and the LED light bulb will light up.  The more current flowing, the brighter the light.

I periodically "test the tester" by purposely connecting 24v (+) or 24v (-) (one at a time) to bonding and then switching the Masse + and Masse - to make sure the LED light lights up.  I do this behind the Nav station "curtain" as there is relatively easy access to 24v (+), 24v (-) and the Yellow/Green bonding wire.  Usually I do it right after I read a thread like this one!  The test has always worked and thankfully, I have never found a leak.  

Hope this helps!

--
Mark McGovern
SM #440 Cara
Seal Bay, ME USA


Paul Stascavage
 

Here is a new photo Bill

i have disconnected the extraneous wire bit the short still exists. I will try to trace those wires but they don’t appear to be the cause of the current issue as I’m certain that they have been there since I took ownership. 


Paul


Paul Stascavage
 

Mark,

Thank you for correcting my statement to John and the education regarding voltage vs current.

I am very confused.

The bulb on the Masse Test Light is NOT illuminating on either the POSITIVE or the NEGATIVE side although it used to on the NEGATIVE side. The illumination started shortly after taking ownership in 2016. I had the electrician in Martinique look into that negative leak and he said is was a very small current and not to worry about it but keep an eye on the zincs - which is what I have done since.

Fast forward the clock to a few months ago, and the Masse stopped illuminating on the NEGATIVE side however, when I looked at the zincs, they were very deteriorated so I decided I should test for a leak with the volt meter.

Yesterday I was seeing a very small leak on the negative side of approximately 0.009 volts but I saw 25+ volts on the positive side and that is what got me all worked up and initiated the post.  When taking my readings yesterday I went directly from the battery bank to the yellow/green on the rudder post.  The testing I did last night and this morning was on the wall (or as you say curtain) behind the Nav Station.  At this location, I show house bank voltage on the POSITIVE side and 0.14 volts on the NEGATIVE side with the navigation instrument breaker in the ON position.  I am seeing 0.07 volts on both the POSITIVE and NEGATIVE side when testing with the navigation breaker in the OFF position.  I’m getting these readings when testing between the POS or NEG terminals and the Yellow/Green Bonding wire on the bus labeled “NAVIGATION” just to the right or aft of the bus labeled “PERMANENT”.

You are saying that house bank voltage on the POSITIVE side is normal?

If this is the case, how do I properly test for leakage as I believe the Masse Test Light may not be functioning currently?

All the best,

Paul Stascavage
SM #466 - s/v Rita Kathryn
Currently Exploring City Island, NY

www.RitaKathryn.com


Paul Stascavage
 

John,

According to Mark, it appears that your statement regarding the readings being correct are correct.

I was freaking out seeing house bank voltages (24 V+) between the POSITIVE side and BONDING side, but according to Mark, this is indeed what we should see.

I verified that my Masse Test Light is indeed working, as Mark suggested, by jumping POSITIVE to BONDING then NEGATIVE to BONDING and seeing if the respective light illuminates - they did.

As Mark explained it, seeing voltage only indicates potential for current flow.  

Hence, it appears we don’t currently have a leak - no measurable current flow.  I’m going to change the zincs and keep a close eye on the new ones.

Thank you Bill H, Bill R, John, and Mark for your help.  In the end, it turns out I didn’t have a problem in the first place, but you all helped me reach that conclusion, and learn a good deal in the process.

All the best,

Paul Stascavage
SM #466 - s/v Rita Kathryn
Currently Exploring City Island, NY

www.RitaKathryn.com


Alan Leslie
 

Hi Paul,

I think things have gone a little awry in this discussion.

The positive and negative sides of your battery bank should float i.e.NOT be connected anywhere to the bonding system  (the green/yellow wires to the zincs, sometimes erroneously called "ground")

So, with your multimeter on VDC  you should measure close to no volts (no potential) between +ve to the bonding wire, and -ve to the bonding wire.

The fact that you read +25 VDC between the +ve and the bonding wire  tells you that, somewhere, the -ve from your battery bank is connected to the bonding.

This is what the MASSE lights tell you....either +ve is connected to the bonding or -ve is connected to the bonding, somehow.

The fact that when you flip the navigation breaker to OFF (it's a double pole breaker and breaks both +ve and -ve) the 25VDC between +ve and bonding goes away, tells you that the -ve is connected to the bonding somewhere AFTER that breaker.

So, this means that on some piece(s) of equipment powered by that breaker there is a connection between -ve and the bonding.

As Bill said, this can often be a "meticulous" electrician taking a wire from an instrument "ground" connection to the bonding.
A lot of instruments have their "ground" connection internally connected to -ve and that will cause this issue.
It could also be that this "meticulous" electrician took a wire from the metal case of some piece of equipment powered by this breaker, and connected it to the bonding.

You need to identify each piece of equipment that is powered by that breaker and check to see if there is a wire from it connected to the bonding system...when you find it (them), remove it.

None of your electronic equipment should have the "ground" connection connected to the bonding. The bonding is for electrolysis prevention, and is connected to all the metal parts in the boat that are in contact with sea water. It is NOT electrical "ground".

Hope this helps

Cheers

Alan
Elyse SM437



Martin Birkhoff
 

Hi all,

is there a technical drawing or sketch showing the components of a SM or 54 connected to the bonding system. If a sketch doesn´t exist a list of components would be helpful too. 
Background is I found a loose bonding cable beneath the engine and have no idea where it was fixed. 

Regards

Martin

Mago del Sur 54#40
Alicante, Spain


Alan Leslie
 

Hi Martin,

Many Amel boats have been modified (ours included) and perhaps this binding wire was for a piece of equipment that had a metallic connection to saltwater, but that piece of equipment is no longer there. 
For example we replaced the Calpeda Air con pump with a March pump. The Calpeda pump is all metal and has a bonding wire connected usually to the metal one way valve on the outlet. The March pump has no metal parts in contact with salt water hence no need for a bonding wire...so it is no longer connected.

Rather than a list of components, as I said many Amels have been modified, you should check and be sure that EVERY metallic part that is in contact with sea water has a bonding wire attached to it...and that bonding wire is connected to the rudder zincs.

Cheers
Alan
Elyse SM437


 

Paul,

I helped you find a potential problem with the two unknown wires connected to the negative side of the 24v PERMANENT BUS.

Did you trace those?

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 Wed, Sep 8, 2021, 5:57 AM Alan Leslie <s.v.elyse@...> wrote:
Hi Martin,

Many Amel boats have been modified (ours included) and perhaps this binding wire was for a piece of equipment that had a metallic connection to saltwater, but that piece of equipment is no longer there. 
For example we replaced the Calpeda Air con pump with a March pump. The Calpeda pump is all metal and has a bonding wire connected usually to the metal one way valve on the outlet. The March pump has no metal parts in contact with salt water hence no need for a bonding wire...so it is no longer connected.

Rather than a list of components, as I said many Amels have been modified, you should check and be sure that EVERY metallic part that is in contact with sea water has a bonding wire attached to it...and that bonding wire is connected to the rudder zincs.

Cheers
Alan
Elyse SM437


Mark McGovern
 

Alan,

From your answer I'm guessing I'm the one who sent things a bit awry.  Thanks for trying to get things back on track.  Clearly, I have a similar issue to Paul. I am hoping you can help me understand what I am seeing on my boat:

1.  Masse + light does not light when I move switch to Masse +
2.  Masse - light does not light when I move the switch to Masse -
3.  If I purposely connect a wire from +ve to Bonding, Masse + light turns on when I move the switch to Masse +
4.  If I purposely connect a wire from -ve to Bonding, Masse - light turns on when I move the switch to Masse -
5.  I measure pretty close to house bank voltage between +ve and Bonding (26.5v).
6.  I measure house bank voltage between +ve and -ve (26.5v)
7.  I measure zero volts between -ve and Bonding
8.  I measure 10-12 mega ohms resistance between -ve and Bonding

So based on this information and what you wrote, it appears that somewhere I have a connection between -ve and Bonding.  That connection is clearly not a good connection given that the Masse - light does not light up (unless I purposely make a good connection between -ve and Bonding) and given the really high resistance I have between -ve and Bonding.  Would you agree? If not, what do you think is happening?

Thanks,
Mark

--
Mark McGovern
SM #440 Cara
Belfast, ME USA


Alan Leslie
 
Edited

Hi Mark,

Yes, it would seem that you have a very slight leak between the -ve and the bonding.

When you say that the MASSE -  light doesn't come on, have you observed it in the dead of night with no ambient light?

I can give you an illustration of what I had once.
I noticed a faint glimmer, only observable at night on the MASSE -. Couldn't see it in the daytime.
By a process of elimination I found the cause.
It was the AC power pack used to power the laptop. 
Because at that time I still had the Calpeda Air con pump, the bonding was also connected to the AC ground through that pump - standard Amel.
The AC/DC power pack for the laptop must have had a high resistance internal connection from DC-ve to AC ground, because when I unplugged the AC connection the MASSE - light went off, similarly if I disconnected all the USB connections I had between the laptop and the nav instruments, the MASSE - light went off.
BUT I could only see the MASSE - light in the dark....daytime it looked fine.

In a previous boat I had a similar issue with a negative wire that was wet....no real connection to anything, just damp.

Something like that could be the cause of your circumstance.

In Paul's case, it seems clear to me that it's something on the powered side of the nav instruments cct breaker that is causing his issue.

Cheers
Alan
Elyse SM437