[Amel Yacht Owners] Re: Prop Shaft Electrolysis


karkauai
 

Thanks, Alan.
I'm not sure I understand the capacitance thing, but that's what the electrician thinks, too.  What kind of fault would lead to a capacitance?  I take it that means something is storing up some energy that flows when the battery switch is turned off, but is rapidly depleted.  There are a lot of capacitors in these boats...are we talking about a fault in one of them, or a fault that somehow acts as a capacitor?

Really don't understand why the DC voltage between the negative battery pole and the bonding system goes up when the 220 breaker is closed (on).  That's somehow an AC power supply showing up as a DC voltage, even when the power to the chargers is shut off.   Arrrgh.

Thanks again,
Kent



From: "divanz620@... [amelyachtowners]"
To: amelyachtowners@...
Sent: Saturday, January 24, 2015 7:11 PM
Subject: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

 
Hi Kent,

Congratulations on the receipt of the C-drive...hope the installation goes well.

Regarding your electrical scenario.....it sounds like there's a capacitance between the earth bonding system and the negative battery connection.
If the boat was in the water that could be the seawater if the negative power to your SSB and tuner are connected to the SSB ground plate. But I guess you're not in the water so that doesn't work.

But somewhere there is some kind of capacitive leak from the 24V negative circuit to the earth bonding.
It could be a faulty appliance which has an earth bonding connection and 24V supply?

Regarding the engine beds, the engine is isolated from the beds by the mounts so I guess it doesn't matter if the beds are bonded or not, the engine parts that come in contact with seawater are bonded, that's the important thing.

Hope there are some gurus out there that can help you further.

Cheers
Alan
SV Elyse SM437
Gulf Harbour
 




Alan Leslie
 

Bills reply also helpful....
What I mean is that maybe there is an electrical device which is faulty and has a capacitive leak to ground.
As Bill says, likely cuplrits are the toilet macerator pumps.
As for the AC breaker causing similar symptoms...maybe you have a faulty 220VAC appliance as well i.e one with an internal ground fault...do all your 220VAC appliances work OK?  Do any of them trip the AC breaker when you turn them on ?
The only way to find it is to disconnect things until the symptoms go away and identify the culprit.
Cheers
Alan
SV Elyse SM437
Gulf Harbour.


karkauai
 

Thanks again, Alan,
All the 220 appliances seem to work fine.  The only thing that tripped the breaker once was a blow dryer when other things were already running.

When you say disconnect things...I've opened all the breakers on the boat now (engine room, galley, nav station, winches, windlass, bow thruster) and still get the  3-8V DC voltage between 24V negative pole and bonding system. Out of curiosity, I checked the positive battery pole with the bonding system and got 19V.  Do I need to actually disconnect power to each appliance/pump/etc, or is turning the breaker off adequate?

Kent



From: "divanz620@... [amelyachtowners]"
To: amelyachtowners@...
Sent: Saturday, January 24, 2015 9:36 PM
Subject: Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

 
Bills reply also helpful....
What I mean is that maybe there is an electrical device which is faulty and has a capacitive leak to ground.
As Bill says, likely cuplrits are the toilet macerator pumps.
As for the AC breaker causing similar symptoms...maybe you have a faulty 220VAC appliance as well i.e one with an internal ground fault...do all your 220VAC appliances work OK?  Do any of them trip the AC breaker when you turn them on ?
The only way to find it is to disconnect things until the symptoms go away and identify the culprit.
Cheers
Alan
SV Elyse SM437
Gulf Harbour.



Bill & Judy Rouse <yahoogroups@...>
 

Kent,

WRONG, the engine is isolated from the angle iron by the mounts. The wire from the zincs should connect with all of the other wires above the gray water bilge.

Bill
BeBe 387



On Sat, Jan 24, 2015 at 9:11 PM, Kent Robertson karkauai@... [amelyachtowners] <amelyachtowners@...> wrote:
 

Thanks, Bill,
We ran out of time, the electrician is coming back tomorrow.  In the meantime, I'll check with all of the 24V breakers off (galley, engine room, windlass, winches, etc).  If the voltage is gone, I'll switch them on one at time and see what happens...starting with the electric heads.

The bonding wires still go to the strap that goes to the keel bolt, and there are two that go from the strap to the engine and the top of the CDrive.  None go from the strap to the angle irons, but the bonding wire that goes to the zincs is attached to the angle iron.  I guess if the engine is connected to the bonding wires from the rest of the boat, and is connected to the angle iron, the engine completes the circuit to the zincs.....right?

I did have the bonding strap to the keel bolt replaced about 5 years ago, and I had the engine replaced a couple years later.  I suppose that during one of those projects someone could have missed a connection somewhere.

I'll let you know what I find.
Kent


From: "'Bill & Judy Rouse' yahoogroups@... [amelyachtowners]" <amelyachtowners@...>
To: "amelyachtowners@..." <amelyachtowners@...>
Sent: Saturday, January 24, 2015 9:18 PM
Subject: Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

 
Kent,

It is hard to diagnose via an email which does not have all of the facts.

One question about your electrician...With the 24v battery switch ON, and the 220V shore power DISCONNECTED (UNPLUGGED), did the electrician try to locate a faulty 24 volt item that is connected to the bonding system? If he did not try this, I suggest that you might need another electrician.

The most likely item(s) that I can think of that is/are 24 volt, connected to the bonding system, and might be faulty is/are the macerator pumps on the side of the electric toilets, and/or the salt water toilet supply pumps (assuming that Kristy has the electric toilets. You might try turning OFF the WC breaker which is located in the engine room forward bulkhead (on BeBe 387). Use a volt meter to ensure that none of the pumps are still getting DC current...If the 3 volt voltage disappears, you found the culprit. Next, you will have to isolate which pump by disconnecting one at a time. Let me know if this works for you or not...if not, I need to know all of your 24 volt items and I will try to come up with another suspect item.

Also (on BeBe 387), all of the bonding wires were routed by Amel to the gray water bilge ground strap, where they were soldered to the top of the ground strap. I'm not sure, but I believe that your boat was originally built this way...if so, there has been a lot of changes. Let me know what you can about how your boat was originally wired, or someone else on this forum with a hull number before Kristy 243, can answer this question.

Best,

Bill
BeBe 387



On Sat, Jan 24, 2015 at 6:11 PM, divanz620@... [amelyachtowners] <amelyachtowners@...> wrote:
 
Hi Kent,

Congratulations on the receipt of the C-drive...hope the installation goes well.

Regarding your electrical scenario.....it sounds like there's a capacitance between the earth bonding system and the negative battery connection.
If the boat was in the water that could be the seawater if the negative power to your SSB and tuner are connected to the SSB ground plate. But I guess you're not in the water so that doesn't work.

But somewhere there is some kind of capacitive leak from the 24V negative circuit to the earth bonding.
It could be a faulty appliance which has an earth bonding connection and 24V supply?

Regarding the engine beds, the engine is isolated from the beds by the mounts so I guess it doesn't matter if the beds are bonded or not, the engine parts that come in contact with seawater are bonded, that's the important thing.

Hope there are some gurus out there that can help you further.

Cheers
Alan
SV Elyse SM437
Gulf Harbour
 






Bill & Judy Rouse <yahoogroups@...>
 

Kent,

If I were you, I would deal with the DC problem first...and I would do it with the shore power plug unplugged.

Bill
Bebe 387

On Sat, Jan 24, 2015 at 9:22 PM, Kent Robertson karkauai@... [amelyachtowners] <amelyachtowners@...> wrote:
 

Thanks again, Alan,
All the 220 appliances seem to work fine.  The only thing that tripped the breaker once was a blow dryer when other things were already running.

When you say disconnect things...I've opened all the breakers on the boat now (engine room, galley, nav station, winches, windlass, bow thruster) and still get the  3-8V DC voltage between 24V negative pole and bonding system. Out of curiosity, I checked the positive battery pole with the bonding system and got 19V.  Do I need to actually disconnect power to each appliance/pump/etc, or is turning the breaker off adequate?

Kent


From: "divanz620@... [amelyachtowners]" <amelyachtowners@...>
To: amelyachtowners@...
Sent: Saturday, January 24, 2015 9:36 PM
Subject: Re: [Amel Yacht O wners] Re: Prop Shaft Electrolysis

 
Bills reply also helpful....
What I mean is that maybe there is an electrical device which is faulty and has a capacitive leak to ground.
As Bill says, likely cuplrits are the toilet macerator pumps.
As for the AC breaker causing similar symptoms...maybe you have a faulty 220VAC appliance as well i.e one with an internal ground fault...do all your 220VAC appliances work OK?  Do any of them trip the AC breaker when you turn them on ?
The only way to find it is to disconnect things until the symptoms go away and identify the culprit.
Cheers
Alan
SV Elyse SM437
Gulf Harbour.




karkauai
 

Thanks again Bill,

I'll start again in the morning with the shore power disconnected.

On Kristy, the insulating (vibration dampening) motor mounts are between the hull and the angle irons.  The engine is bolted directly to the angle irons (with spacers that align it with the CDrive).  There is no insulation between the engine and the angle irons.  Is that not how all SM's are set up?

Kent



From: "'Bill & Judy Rouse' yahoogroups@... [amelyachtowners]"
To: "amelyachtowners@..."
Sent: Saturday, January 24, 2015 10:28 PM
Subject: Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

 
Kent,

If I were you, I would deal with the DC problem first...and I would do it with the shore power plug unplugged.

Bill
Bebe 387

On Sat, Jan 24, 2015 at 9:22 PM, Kent Robertson karkauai@... [amelyachtowners] <amelyachtowners@...> wrote:
 
Thanks again, Alan,
All the 220 appliances seem to work fine.  The only thing that tripped the breaker once was a blow dryer when other things were already running.

When you say disconnect things...I've opened all the breakers on the boat now (engine room, galley, nav station, winches, windlass, bow thruster) and still get the  3-8V DC voltage between 24V negative pole and bonding system. Out of curiosity, I checked the positive battery pole with the bonding system and got 19V.  Do I need to actually disconnect power to each appliance/pump/etc, or is turning the breaker off adequate?

Kent


From: "divanz620@... [amelyachtowners]" <amelyachtowners@...>
To: amelyachtowners@...
Sent: Saturday, January 24, 2015 9:36 PM
Subject: Re: [Amel Yacht O wners] Re: Prop Shaft Electrolysis

 
Bills reply also helpful....
What I mean is that maybe there is an electrical device which is faulty and has a capacitive leak to ground.
As Bill says, likely cuplrits are the toilet macerator pumps.
As for the AC breaker causing similar symptoms...maybe you have a faulty 220VAC appliance as well i.e one with an internal ground fault...do all your 220VAC appliances work OK?  Do any of them trip the AC breaker when you turn them on ?
The only way to find it is to disconnect things until the symptoms go away and identify the culprit.
Cheers
Alan
SV Elyse SM437
Gulf Harbour.






Alan Leslie
 

Yes ...you are right...sorry...but if the engine itself is connected to the ground bonding system then the angle irons don't need to be as they are connected to the engine.
Sorry for the incorrect information (the result is the same )...I;ll try to do better next time !!

opening all the DC breakers only disconnects the +ve feed, the negative is still connected to the appliances.
You may need to disconnect the negatives one at a time to find the leak.

Cheers
Alan
SV Elyse SM437
Gulf Harbour


karkauai
 

Aha!  OK, that makes sense Alan.  Back to the salt mines.
Kent


On Jan 24, 2015, at 11:08 PM, divanz620@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Yes ...you are right...sorry...but if the engine itself is connected to the ground bonding system then the angle irons don't need to be as they are connected to the engine.

Sorry for the incorrect information (the result is the same )...I;ll try to do better next time !!

opening all the DC breakers only disconnects the +ve feed, the negative is still connected to the appliances.
You may need to disconnect the negatives one at a time to find the leak.

Cheers
Alan
SV Elyse SM437
Gulf Harbour


Bill & Judy Rouse <yahoogroups@...>
 

Kent,

I thought the engine was isolated from the frame by the motor mounts, but I am not on the boat and cannot verify that.

When they repowered your boat did they isolate the 12 volt ground with a negative start solenoid? Also, the alternator would have to be for an isolated ground. Is the large alternator originalnwith original wiring. Is it an isolated ground? These are some things that your electrician should be looking at.

I have a friend who added a large Balmor alternator to his Bavaria. He forgot to specify isolated ground. Within about two years his sail drive had to be replaced because electrolysis had eaten it up.

Bill Rouse
BeBe Amel 53 #387
sent from my tablet

On Jan 24, 2015 10:49 PM, "Kent Robertson karkauai@... [amelyachtowners]" <amelyachtowners@...> wrote:
 

Aha!  OK, that makes sense Alan.  Back to the salt mines.
Kent


On Jan 24, 2015, at 11:08 PM, divanz620@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Yes ...you are right...sorry...but if the engine itself is connected to the ground bonding system then the angle irons don't need to be as they are connected to the engine.

Sorry for the incorrect information (the result is the same )...I;ll try to do better next time !!

opening all the DC breakers only disconnects the +ve feed, the negative is still connected to the appliances.
You may need to disconnect the negatives one at a time to find the leak.

Cheers
Alan
SV Elyse SM437
Gulf Harbour


Olivier Beaute
 

Good evening Kent,

the engine is "hard bolted" to the iron frame, which is installed on rubber mounts.
Each and every metallic item should be bonded (no resistance between two pieces of metal).

The fact that you had the engine replaced is probably the cause  of your leak. Did you replace the alternators too?
When you find a voltage between the ground (engine frame) and the +24V, did you try to connect a bulb there? If the light shows, then it is a leak, if not it's a capacitance (not dangerous).
The leak may come from your alternators that may not be isolated ones. You won't be able to trace this kind of leak with breakers, there aren't any breaker on the alternators.
This means you must disconnect them and check the leak after each disconnection. Start with disconnecting the positive on the 24V alternator, then the positive on the 12V alternator. Be careful to put some adhesive tape on the wire's end (because this is +24V or +12V alive!!).
Then disconnect -24V and -12V.
If you still get some voltage, it may come through the excitation circuit on the alternators (small wires)., then disconnect them too (although they should be fed only while the engine is running, but you never know...)

Tell me your observations.

Good luck.

Olivier




On Sunday, January 25, 2015 3:03 PM, "'Bill & Judy Rouse' yahoogroups@... [amelyachtowners]" wrote:


 
Kent,
I thought the engine was isolated from the frame by the motor mounts, but I am not on the boat and cannot verify that.
When they repowered your boat did they isolate the 12 volt ground with a negative start solenoid? Also, the alternator would have to be for an isolated ground. Is the large alternator originalnwith original wiring. Is it an isolated ground? These are some things that your electrician should be looking at.
I have a friend who added a large Balmor alternator to his Bavaria. He forgot to specify isolated ground. Within about two years his sail drive had to be replaced because electrolysis had eaten it up.
Bill Rouse
BeBe Amel 53 #387
sent from my tablet
On Jan 24, 2015 10:49 PM, "Kent Robertson karkauai@... [amelyachtowners]" <amelyachtowners@...> wrote:
 
Aha!  OK, that makes sense Alan.  Back to the salt mines.
Kent


On Jan 24, 2015, at 11:08 PM, divanz620@... [amelyachtowners] <amelyachtowners@...> wrote:

 
Yes ...you are right...sorry...but if the engine itself is connected to the ground bonding system then the angle irons don't need to be as they are connected to the engine.
Sorry for the incorrect information (the result is the same )...I;ll try to do better next time !!

opening all the DC breakers only disconnects the +ve feed, the negative is still connected to the appliances.
You may need to disconnect the negatives one at a time to find the leak.

Cheers
Alan
SV Elyse SM437
Gulf Harbour




karkauai
 

Wow!  I don't have a clue about the start solenoid, Bill.  The 24v alternator and wiring are the same ones that were on the boat when I bought it in 2008...I assume they were original but don't know for certain.  I'll pass this on to the electrician who is working with me.

Thanks!!!
Kent


On Jan 25, 2015, at 9:02 AM, 'Bill & Judy Rouse' yahoogroups@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Kent,

I thought the engine was isolated from the frame by the motor mounts, but I am not on the boat and cannot verify that.

When they repowered your boat did they isolate the 12 volt ground with a negative start solenoid? Also, the alternator would have to be for an isolated ground. Is the large alternator originalnwith original wiring. Is it an isolated ground? These are some things that your electrician should be looking at.

I have a friend who added a large Balmor alternator to his Bavaria. He forgot to specify isolated ground. Within about two years his sail drive had to be replaced because electrolysis had eaten it up.

Bill Rouse
BeBe Amel 53 #387
sent from my tablet

On Jan 24, 2015 10:49 PM, "Kent Robertson karkauai@... [amelyachtowners]" <amelyachtowners@...> wrote:
 

Aha!  OK, that makes sense Alan.  Back to the salt mines.
Kent


On Jan 24, 2015, at 11:08 PM, divanz620@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Yes ...you are right...sorry...but if the engine itself is connected to the ground bonding system then the angle irons don't need to be as they are connected to the engine.

Sorry for the incorrect information (the result is the same )...I;ll try to do better next time !!

opening all the DC breakers only disconnects the +ve feed, the negative is still connected to the appliances.
You may need to disconnect the negatives one at a time to find the leak.

Cheers
Alan
SV Elyse SM437
Gulf Harbour


karkauai
 

Hi Mike,
I just got this from one of the real Amel gurus.  Don't know if significant, but I know that the start solenoid on the Yanmar is different from the old Volvo.
Whatchathink?
Kent


On Jan 25, 2015, at 7:00 PM, Kent Robertson <karkauai@...> wrote:

Wow!  I don't have a clue about the start solenoid, Bill.  The 24v alternator and wiring are the same ones that were on the boat when I bought it in 2008...I assume they were original but don't know for certain.  I'll pass this on to the electrician who is working with me.

Thanks!!!
Kent


On Jan 25, 2015, at 9:02 AM, 'Bill & Judy Rouse' yahoogroups@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Kent,

I thought the engine was isolated from the frame by the motor mounts, but I am not on the boat and cannot verify that.

When they repowered your boat did they isolate the 12 volt ground with a negative start solenoid? Also, the alternator would have to be for an isolated ground. Is the large alternator originalnwith original wiring. Is it an isolated ground? These are some things that your electrician should be looking at.

I have a friend who added a large Balmor alternator to his Bavaria. He forgot to specify isolated ground. Within about two years his sail drive had to be replaced because electrolysis had eaten it up.

Bill Rouse
BeBe Amel 53 #387
sent from my tablet

On Jan 24, 2015 10:49 PM, "Kent Robertson karkauai@... [amelyachtowners]" <amelyachtowners@...> wrote:
 

Aha!  OK, that makes sense Alan.  Back to the salt mines.
Kent


On Jan 24, 2015, at 11:08 PM, divanz620@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Yes ...you are right...sorry...but if the engine itself is connected to the ground bonding system then the angle irons don't need to be as they are connected to the engine.

Sorry for the incorrect information (the result is the same )...I;ll try to do better next time !!

opening all the DC breakers only disconnects the +ve feed, the negative is still connected to the appliances.
You may need to disconnect the negatives one at a time to find the leak.

Cheers
Alan
SV Elyse SM437
Gulf Harbour