Engine and devices grounded to hull?? This looks weird.

[clendee]

If I am 'for testing purposes' connecting the battery + and - directly to the alternator + and -, what sized cable should I be using for that?

 

Also, Ive read that alternators require sufficient revs to charge the batteries.

Edited April 25, 2023 by clendee

[Tony Brooks]

48 minutes ago, clendee said:

If I am 'for testing purposes' connecting the battery + and - directly to the alternator + and -, what sized cable should I be using for that?

 

Also, Ive read that alternators require sufficient revs to charge the batteries.

 

Simply for testing then 4 sq mm CCSA would do, but if the battery is well discharged it might overheat and catch fire, the output would also be limited.  We used to use 50/0.30mm cable on low output alternators but for 70 amps I would go larger.

 

I don't understand why you want to do this, why not simply trace the alternator pos and neg main leads to ensure that one way or another they connect the alternator to the batteries.

 

An alternator may or may not energise at idle revs, so you often have to give the engine some revs upon initial start up. Because of the large pulley ratio you have, I suspect that you will get a respectable output at idle, but this is bad for the alternator because its cooling fan will not move sufficient air. Without an ammeter it is hard to determine what speed to run the engine for battery charging but between 1000 and 2000 rpm is typical, then gradually reducing as the batteries charge and the charging current drops.

 

 

[clendee]

https://yewtu.be/watch?v=IGsFNjRC0mY
 

What do ye think of this guy?  I have watched MANY of his videos.  This one is on alternator troubleshooting.  He's mainly talking about sea going craft but I believe the principles still apply.   He is based in Canada, so wiring gauges are in AWG and AC implementations are at 110V. 

 

I understand it doesn't really solve my issues, but I thought things were very well explained, especially his other videos.

Edited April 26, 2023 by clendee

[Tony Brooks]

10 minutes ago, clendee said:

https://yewtu.be/watch?v=IGsFNjRC0mY
 

What do ye think of this guy?  I have watched MANY of his videos.  This one is on alternator troubleshooting.  He's mainly talking about sea going craft but I believe the principles still apply.   He is based in Canada, so wiring gauges are in AWG and AC implementations are at 110V. 

 

I managed to get through about three minutes or so before making a few random jumps.  A lot of words and apparently no knowledge of UK BSS requirements. Also for what I managed to watch nothing about fault-finding the circuits. Following his advice would put you at odds with a BSS inspector IF the BSS inspector strictly interpreted their rules and took time to examine the boat. This relates to the domestic master switch. My advice (well I would say this) is to stick to advice from people with experience of UK inland boating and be very wary of anything you find on UTube unless you can verify the presenter's experience and depth of expertise.

[clendee]

41 minutes ago, Tony Brooks said:

 

I managed to get through about three minutes or so before making a few random jumps.  A lot of words and apparently no knowledge of UK BSS requirements. Also for what I managed to watch nothing about fault-finding the circuits. Following his advice would put you at odds with a BSS inspector IF the BSS inspector strictly interpreted their rules and took time to examine the boat. This relates to the domestic master switch. My advice (well I would say this) is to stick to advice from people with experience of UK inland boating and be very wary of anything you find on UTube unless you can verify the presenter's experience and depth of expertise.

Ok, thanks for the heads up on this.  Yes it is a different regulatory body.  This presenter (from his previous vids) has safety at the forefront of his work.   Thanks for your thoughts, I'll be looking at my alternator in a few days and look forward to digging through the options.

 

But you are right, I'd love if there was a series for BSS standards.

Edited April 26, 2023 by clendee

[Tony Brooks]

When you next go to the boat I suggest that you approach the job like this.

 

Turn the master switches off AND disconnect both battery bank negatives.

 

Take the thick red wire of terminal 61 and connect it to B+. Insulate the other two cables for now.

 

Reconnect the batteries and turn on master switches.

 

Connect a multimeter set to 20V DC between the B+ terminal and a battery negative. It should read battery voltage. If it does not then:

 

1. Ensure the engine and domestic battery negatives are linked with thick battery sized cable (or if there is no other option use any cable but take it off once you get battery voltage).

 

2. Trace the B+ cable and ensure that one way or another it ends up at a battery positive, this may go via a master switch, but I think you earlier said it was connected to the domestic bank positive.

 

 

The next step is to sort out the B- cable.

 

If a thickish cable is connected to B- put the volt meter between B+ and B-. It should read battery voltage, if it does not then:

 

1. Ensure the engine and domestic battery negatives are linked with thick battery sized cable (or if there is no other option use any cable but take it off once you get battery voltage).

 

2. Trace the B- cable and ensure that one way or another it ends up at a battery negative.

 

If there is no thickish black cable hanging about make up a short length of cable, similar size wise to that on B+, and connect it between B- and a mounting bolt. You can later change this for a cable that runs between B- and whichever battery many negative that the B+ connects to.

 

Now check by using the voltmeter between B+ and B-. it should read battery voltage. If it does not then the engine block may not be bonded to battery negative.

 

If all that checks out we then need to sort out the charge warning lamp.

 

One of the thin wires on 61 is almost certainly the warning lamp cable. The other may well run to the split charge relay 6mm blade positive terminal (the red and white one). This one is not required to get the alternator charging.

 

I assume/hope not to much messing about has been done with the panel wiring.

 

Turn on the ignition switch (do not start the engine).

 

The charge light should be OFF.

 

Take one of hose two thin wire, I would suggest the green one, and touch the metal part of the terminal on the cable to any clean metal, probably the alternator case. As you do so the charge light should come on. If it does not:

 

1. try the other cable.

 

2. Check the wiring on the diose plate accords with the diagram. Ensure the wires on 3,4,7&8 are in place.

 

3. Run a cable from terminal 58 on the ignition switch (ignition on) to one terminal on the charge warning lamp (red I think and a 6mm blade) and another from the other lamp terminal to 61 on the alternator. Before you connect this cable turn on the ignition and touch the cable terminal to negative as above, to check the bulb works. Note, this removes the parallel resistor that is on the diode board so the alternator may not energise (Bukh specific point).

 

Put the voltmeter across + to – of which ever battery the alternator is connected to and start the engine. Rev to say 1500 rpm. Hopefully the lamp will go out and the voltmeter will jump up.

If this does not happen then leave the engine running and use a small length of cable to touch between B+ and 61. The lamp should go out and the voltmeter jump to a higher reading.

 

 

If all this happens then you have a working alternator. If I does not I fear the alternator is faulty.

 

If you have had to bypass the diode board , I don’t think that you will have to, post a photo of the board and back of the panel.

 

 

Now the split charge relay.

 

Cut to lengths of the thicker red lead on the charger and fit eye terminal that will allow you to fit one length between one relay terminal and a terminal on one master switch and the other length on the other relay terminal and the other master switch.

 

Now to energise the relay.

 

If you take connect the red and white cable to the relay and touch the other end on B+ you should hear or feel the relay close. If so the relay circuit is fine.

 

You can reconnect to terminal 61 but it may bring back the buzzer “malfunction”. If it does then I ran mine with it connected to the alternator W terminal. This is not best practice but it worked reliably for many years until I fitted a VSR in place of the spilt charge relay to enable the solar to charge both banks unattended.

 

 

Report back and then we can look at your original question, but I fear that you need to trace where the two thicker black wires run to/from and tell us, we will also need to know about any other negative connections.

Edited April 26, 2023 by Tony Brooks

[clendee]

Thank you so much for this breakdown.

I look forward to returning the results of this experiment.

 

My signal can be a bit rubbish out there, but I hope to respond onsite.

 

I can say for sure that there is no cable connected to B- on the alternator

Please note, this is the old alternator, that I thought was blown.  That thick black cable to the left of the alternator goes to the negative of the starter battery (I believe, I will confirm this).

 

Also the image of my battery setup below, this is an early photo but its still the same setup but the bilge pump has been wired into the panel now and the negative was moved to the other house battery (positive on house battery 1, negative on house battery 2).

Edited April 26, 2023 by clendee

[Tony Brooks]

It does not look as if the engine battery and domestic bank negatives are linked, unless they are linked elsewhere. This complicates things a bit, but using similar sized cable, just put a link in for now and leave the rest as it is for later attention. The lack of this link might explain the feature you originally asked about.

 

Sorry about this, but unless all those battery clamps are soldered to the cables I think they should result in a BSS fail. This type of clamp and eye terminal on the cables are compliant and makes things far easier, like fitting that link cable.

 

The thin red and black cables are not best practice UNLESS it is for a specific type of battery monitor, but as long as the BSS bod is happy it can stay for now. What does it feed?

 

Just another "not best practice" but almost certainly OK for the foreseeable. In an ideal world, the domestic main negative and positive would come from opposite corners of the bank, but this is far from urgent, and I doubt the theoretical disadvantage will become apparent.

 

This sort of thing is to be expected when you buy an older boat that has been subject to inexpert DIY.

Edited April 26, 2023 by Tony Brooks

[TheBiscuits]

1 hour ago, Tony Brooks said:

This sort of thing is to be expected when you buy an older boat that has been subject to inexpert DIY.

 

Oddly, I was thinking that apart from the crap type of terminal clamps that battery wiring looks far better than most of the rat's nests we get pictures of!

 

 

[Tony Brooks]

7 hours ago, TheBiscuits said:

 

Oddly, I was thinking that apart from the crap type of terminal clamps that battery wiring looks far better than most of the rat's nests we get pictures of!

 

 

 

True, as far as the look goes. But the more you look at the wiring, the worse it looks. I am sure those screw on battery clamps are against the BSS unless soldered.

[Tracy D'arth]

1 hour ago, Tony Brooks said:

 

True, as far as the look goes. But the more you look at the wiring, the worse it looks. I am sure those screw on battery clamps are against the BSS unless soldered.

They certainly used to be.  Get some cable protection around that hole in the steel before the cables chaff through and set on fire.

[Jen-in-Wellies]

1 hour ago, Tony Brooks said:

 

True, as far as the look goes. But the more you look at the wiring, the worse it looks. I am sure those screw on battery clamps are against the BSS unless soldered.

3.4.1 Are all battery cable connections effective and in good condition? R
For the cables listed at Check Item
3.2.2, visually check the type and
condition of all the cable connections
(including those at the batteries,
battery isolators, and the
engine/equipment, etc), where they
can be seen.
All battery cables listed at Check Item 3.2.2 must be fitted with
soldered or crimped lug connectors or other connections of
suitable proprietary manufacture.
All battery cable connections on cables listed at Check Item
3.2.2 must not show signs of damage or deterioration,
including:
• missing or loose components; or,
• excessively exposed and/or damaged cable strands; or
• heat damage; or,
• corrosion.
Applicability – battery terminals fitted with screw clamps are acceptable if the cable strands are
protected by the use of spreader plates or tinned cable ends in the terminal.

[clendee]

Thanks for all your feedback (above) re my battery connections. I understand the conditions are less than perfect.  I will purchase the necessary connectors and redo the battery connections as per BSS standards.

 

Ok, here is the current setup.  [Just saying as its connected now, before I start doing anything.]  Unfortunately, I've go some pain in my arms, in a tennis elbow kind of way which is limiting my capabilities, you couldn't write this stuff]

 

CURRENT SETUP

Alternator, red cable on 61 -> Left hand side of Relay -> Right and side of relay -> Master switch -> Domestic battery.

 

Alternator minus (-), there is a very small black cable on this post which seems to be connected to the casing of the alternator.  Near the alternator casing is a thick black cable [not directly connected to the alternator], and this cable runs back to the negative of the starter battery.

 

The negatives of the starter and domestic are not connected together (currently).

 

PROPOSED SETUP

Based on your notes, here are some presumptions Im making and what Im going to do:

1) Move the red cable from 61 to the B+ post

2) Bypass the relay with a red cable directly connected to main starter switch

3) Do a multimeter test on voltage between B+ and Neg starter battery.

 

I hope Im intrepeting this correctly.

 

I know this is just the initial section of your notes, Ive read them a few times trying to make sure I understand what Im doing.

 

You mention half way down the page to 'connect it between B- and a mounting bolt'. Not sure I understand what a mounting bolt is?

 

Sorry if these are dumb questions, I appreciate your patience.

Edited April 28, 2023 by clendee

[Tony Brooks]

No question is dumb if you don't know or understand the answer.

 

OK, that red cable on the relay needs moving to the domestic battery maser switch. For BSS the switched side, but may put it on the battery side.

 

Next, link the two battery bank negatives with thick cable. If you do not do this, you either have extra hull bonds or the engine or domestic fuses may not blow on faults, so you risk a fire. Once you do this you can test between positive and any negative, even bits of hull or engine as long as there is no paint or dirt on them. This is the normal way of wiring boats.

 

On NO account take your step 2. No charging cable should be connected to the starter switch. In the majority of cases, the switch will burn out. Note - on many VEHICLES (not boats with two battery banks) the main charging cable uses the starter battery connection as a junction box, but why both the chap on your video and myself have explained why that is not the best idea.

 

Then do as I explained. Connect the thick black cable that you say is near the alternator to the B-. Leave the thin cable in place because I think it goes to the regulator, not the case. Even if it does go to the case the thick wire will supersede it, so the thin one will not do anything.

 

Now you confirm the thick black wire runs to the engine battery negative, there is no need to make a B- connection to anything other than where it goes to now. A mounting bolt is a bolt that mounts something, so a bolt holding the alternator onto the engine.

 

The alternator is very unlikely to charge without the warning lamp connected, so follow the steps related to that as well.

 

Once you get it charging, test the relay wiring as I described.

 

Once the alternator is working - it will be charging the domestic bank - make up the two thick wires to connect the relay to the master switches.

 

Good luck.

 

Basically put the thicker red and black cables where they should be, ensure the warning lamp works and the alternator should charge.

 

If you have time after all that, trace the two thicker black wires and the thin one on the hull bolt you originally asked about so we know what they are doing. Also ensure one battery negative (usually the engine negative) runs to the engine block or starter negative and then to the hull, using thick cables. The bond to hull is often on the engine bed close to the starter.

[Tony Brooks]

An update for anyone interested.

 

Clendee decided to contact me by email so the forum has not been privy to what has been said and found, but I think he is getting there.

 

He linked both battery bank negatives.

He put the vital cables on the alternator as instructed, but I think he gave himself a bum-steer by not comprehending what he was told. Anyway, it seems he has the domestic bank charging properly from the alternator.

 

I have described again how to wire the spilt charge relay and test it, so await confirmation that the engine battery is charging as well as the domestic. (At least we stopped him changing the main charging cable from the domestic band to the engine battery).

 

Update as and when.

[clendee]

Hi folks.

Thanks for all you help here, especially to Tony who guided me through this.  I got the alternator working with the help of the following diagram.  I have also purchased a voltage sensitive relay and installed that this morning. I now have a fully operational charging install on the boat and I am delighted.

Edited May 21, 2023 by clendee

[Tony Brooks]

1 minute ago, clendee said:

Hi folks.

Thanks for all you help here, especially to Tony who guided me through this.  I got the alternator working with the help of the following diagram.  I have also purchased a voltage sensitive relay and installed that this morning. I now have a fully operational charging install on the boat and I am delighted.

 

Great news and well done.

 

Now we need to answer the original question about those three black cables bolted to a random place on the hull.

 

First of all see if you can visually trace them, so we know where they come from.

 

If that does not work, then put all the boat's electrical equipment on and note all that work. Then disconnect the three cables. Any that do not then work must be "earthing" via that hull point. Once we know that and where they are we can work out a way of getting them to negative properly.

 

If you don't want to do all that, fit an insulated stud terminal, put them all on that, and connect from that to any negative, probably the negative stud on the starter or similar.

 

 

[clendee]

Thanks for continuing this topic Tony.

 

I am back at work at the moment so not on the boat again for a few days.
I will follow up on this once Im out on it again, it'll probably be the weekend.

 

I can tell you for sure that one of the cables is the leisure battery ground and another is the VSR ground.

The other two I'd need to do some tracing.

 

Edited May 21, 2023 by clendee

[Tony Brooks]

47 minutes ago, clendee said:

Thanks for continuing this topic Tony.

 

I am back at work at the moment so not on the boat again for a few days.
I will follow up on this once Im out on it again, it'll probably be the weekend.

 

I can tell you for sure that one of the cables is the leisure battery ground and another is the VSR ground.

The other two I'd need to do some tracing.

 

 

That is the result of originally NOT having the engine and domestic negatives linked and someone having problems getting things working.

 

If you know one is the main domestic battery negative, then I think it would be easiest to avoid running new wires and fit one of these to that metal U section.

and put all the cables on it and maybe document it so others know what it is all about.

 

Ideally, the main lead from the domestic negative (apart from the link to the engine negative) will go to the main negative bus bar that is located close to the fuse/MCB panel, usually just inside the cabin. The all domestic equipment negatives run back to that bus bar. However, it looks as if the part you photographed is a long way from where the main negative domestic bus bar is usually located, so just ensuring it is insulated from the hull would do the job.

[clendee]

I have purchased a negative post online, similar to the picture you shared above.  I will move all the negative cables onto it as you suggested.

 

In a previous message you posted...

"What you think about grounding is not quite true. If there is no negative to the hull bond and a positive shorted to the hull, the result would be that no fuses would blow or circuit breakers trip and the whole hull would become live. That could easily cause excessive hull corrosion."

 

I believe in moving all the cables to the negative post would leave no ground line to the hull, is this ok?

[Tracy D'arth]

No.  You need one heavy cable grounded to the hull from the negative post. Use a different adjacent grounding point to the hull from the 240v AC shore line ground.

You must already have a ground cable to the hull as you can start the engine!  Check where all those negative cable go to.

[Tony Brooks]

27 minutes ago, clendee said:

I have purchased a negative post online, similar to the picture you shared above.  I will move all the negative cables onto it as you suggested.

 

In a previous message you posted...

"What you think about grounding is not quite true. If there is no negative to the hull bond and a positive shorted to the hull, the result would be that no fuses would blow or circuit breakers trip and the whole hull would become live. That could easily cause excessive hull corrosion."

 

I believe in moving all the cables to the negative post would leave no ground line to the hull, is this ok?

 

Once again you seem to fail to understand or fail to read what I have said, so to repeat:

 

The domestic bank negative is linked to the engine battery negative by the 25sq mm CCSA (minimum) cable - I think that you have now done this.

 

Another Heavey duty negative cable runs from the domestic bank negative to the negative bus bar in or close to the domestic electrics distribution/fuse/MCB board.

 

Another 25 sq mm CCSA (minimum) cable runs from the engine bank negative to the hull bond point that is usually on the engine bed.

 

If the engine is flexibly mounted (most are) it is usual to continue that negative to the hull bond point to an engine negative bond. This MIGHT be a terminal on the starter body or any nut or bolt on the engine.

 

NOTE: the last two bond points can be reversed, so battery > engine > hull, or battery > hull > engine.

 

The hull is bonded to BOTH battery banks because both bank negatives are linked.

 

 

 

Your engine battery negative must be bonded to the engine in some way otherwise you could not start it.

 

You said that you have linked both bank negatives, so the domestic battery is also bonded to the engine.

 

I don't know if you have flexibly mounted engine or not, or if you have the negative bond between engine and hull IF IT NEEDS ONE (rigidly mounted engines may not).

 

You told me that one of the wires in question came from the domestic battery negative, so as you have now ensured the domestic negative is bonded to the hull/engine via the main engine battery negative, the termination in question can now be isolated from the hull.

 

Edited May 23, 2023 by Tony Brooks

[clendee]

5 hours ago, Tony Brooks said:

"Once again you seem to fail to understand or fail to read what I have said"

 

Once again you seem to fail to understand that I am a 12V electrics novice.

I am so sorry I don't 'get it' on one shot.  

 

I have  been cordial, appreciative, thankful and doing my best to understand.  We all learn in different ways.  The only way to intrepret on this forum is via the written word.  Yes it takes me a few times to get my head around it.

 

Cut me some slack. 

 

 

[Tony Brooks]

2 minutes ago, clendee said:

 

Once again you seem to fail to understand that I am a 12V electrics novice.

I am so sorry I don't 'get it' on one shot.  

 

I have  been cordial, appreciative, thankful and doing my best to understand.  We all learn in different ways.  The only way to intrepret on this forum is via the written word.  Yes it takes me a few times to get my head around it.

 

Cut me some slack. 

 

 

 

How many times do you have to repeat things before you get jarred off. For other members, there is also a fair bit of private email conversion between the two of use where I seemed to be expected to repeat what I had already said on more than one occasion.

 

I accept that you are a novice at 12/24V boat electrics which is why I have been as patient as I have with you, but if, having joined the domestic and engine battery negatives and ensured the engine battery negative is bonded to the hull and/or the block, you can not see that in doing that you have bonded the domestic (& engine battery) negative to the hull then maybe it would be safer to employ a professional than try to learn remotely.

 

 

[Momac]

I would have to remove that label