Nobels Bowthruster dead. Help!

[Markinaboat]

Hi,

 

Well, after living afloat for 15 yrs, we bought our current boat in November which has a 10hp Nobels (elec) thruster. Its worked perfectly. We took off 10 days ago to do the Oxford/Thames ring and yesterday I used the thruster and nowt happened other than the normal whirring noise. When we moored up, we tried it again and was a slower rumble. We were near Fenny Compton and the wonderful Graham Reeves got it in his dry dock hoping to find a blockage. But alas, it was clear. The solenoids are working fine so the assumption is that either the brushes and/or armature need replacing (boat was launched in 2002 but only 1300 hrs on the clock).

 

Aquafax no longer carry parts and they told me to phone Holland. Ive read another blog here on CWDF and read that marine megastore and Allbrights provide the parts, or brushes anyway. But how would I know the tyoe of brushes?

 

If anyone knows anyone well versed in fixing these that may be on our travels (heading south via Cropredy tomorrow then back to Brentfird on the Thames over the next two weeks) then we would be very grateful for contact info.

 

Thanks

[nicknorman]

Are you sure it isn't just that the BT batteries are flat? There are some pretty awful BT charging systems out there.

[Markinaboat]

Are you sure it isn't just that the BT batteries are flat? There are some pretty awful BT charging systems out there.

Definitely not. Same as starter batts. The solenoids click in, it wants to turn but restrcited. Bearings ok as turns freely by hand. Have used dozens of times.

[gaggle]

do you really really need to rely on the girlie button , if its broke be gratefull that you will not in the future have people smirking at you , sorry loked at emojo and cant see just jesting or laughing

, maybe that's against forum rules now

[RLWP]

The solenoids click in, it wants to turn but restricted.

 

Sounds very like a flat battery, that

 

Richard

[nicknorman]

Definitely not. Same as starter batts. The solenoids click in, it wants to turn but restrcited. Bearings ok as turns freely by hand. Have used dozens of times.

But presumably the starter batteries are at the back and the BT batteries are at the front? Long thin wires (even assuming they are connected) will only charge a BT battery very, very slowly. If you haven't already done so I would definitely recommend measuring the BT battery voltage before you start taking anything to bits.

[Markinaboat]

Doesnt anybody read anymore?

Edited September 8, 2016 by Markinaboat

[Markinaboat]

But presumably the starter batteries are at the back and the BT batteries are at the front? Long thin wires (even assuming they are connected) will only charge a BT battery very, very slowly. If you haven't already done so I would definitely recommend measuring the BT battery voltage before you start taking anything to bits.

Never assume anything.

 

This boat is not like the majority. There are no long thin wires. No charging issues. If you read the original post again, you'll see what the issue is. Thanks

[nicknorman]

Never assume anything.

If you read the original post again, you'll see what the issue is. Thanks

No, we'll see what you think the issue is. If "we the forum" accepted people's decisions was wrong with their boats when they ask for help, without questioning it, then nothing much would ever fixed. Anyway it seems that since you are not receptive to suggestions, I can help you no further.

[Markinaboat]

do you really really need to rely on the girlie button , if its broke be gratefull that you will not in the future have people smirking at you , sorry loked at emojo and cant see just jesting or laughing

, maybe that's against forum rules now

I was rather hoping that due yo my detailed post, I woukd only get intelligent replies. Physical impairment means that with the thruster, we can use the boat considerably more now. ... Looking for your mojo's

 

On a more serious note, I'll challenge you to a boat handling competition without BT's. ??

[Markinaboat]

No, we'll see what you think the issue is. If "we the forum" accepted people's decisions was wrong with their boats when they ask for help, without questioning it, then nothing much would ever fixed. Anyway it seems that since you are not receptive to suggestions, I can help you no further.

I did state earlier nick that the batts are the same as the starter batts. 24v system, spins a mighty 3L2 into life in 2 seconds.

 

Further, why would the motor spin at full speed for some time without pushing ANY water out? Clearly, something got jammed but the overheat didnt cut in (or didnt need to, 10hp unit and can run for longer than others Ive seen/experienced) and its burnt out the brushed/atmsture.

 

I do hooe someone can point me the durection of someone who has experience of fixing these so we can continue yo enjoy the longest bost trip of our lives as well as getting er indoors back to work on time. ?

Edited September 8, 2016 by Markinaboat

[Markinaboat]

Sounds very like a flat battery, that

 

Richard

Rchard, woukd the solenoides operste if 24v wasnt getting to them? Woukd slso be a coincidence that the motor was spinning at the normal speed without any movement of water. Thanks

[nicknorman]

I did state earlier nick that the batts are the same as the starter batts. 24v system, spins a mighty 3L2 into life in 2 seconds.

No you didn't. You said "same as starter batts" in response to my comment about charging, so it was not clear whether you meant the same batteries, or the same charging system with the latter being a more logical sequitur from my post.

 

Anyway whilst you are still keeping the layout a secret, most boats have engine batteries somewhere near the rear and a BT at the front. This means long leads with connections that may or may not be faulty. My point was that it would be sensible to check the voltage on the actual BT terminals with the button pressed, to rule out some trivial problem with a connection or battery, before taking the motor to bits. But of course, you know best which is presumably why you are asking on here.

Rchard, woukd the solenoides operste if 24v wasnt getting to them? Woukd slso be a coincidence that the motor was spinning at the normal speed without any movement of water. Thanks

So now you are saying that the motor is spinning at normal speed with no movement of water? How could this possibly be anything to do with the motor brushes?

 

There will be some sort of shear pin / weak link arrangement between the propellor and the motor designed to protect the latter from a sudden stoppage. It sounds like this has done its job and disconnected the drive.

[PaulG]

Rchard, woukd the solenoides operste if 24v wasnt getting to them? Woukd slso be a coincidence that the motor was spinning at the normal speed without any movement of water. Thanks

Because it takes very little power to operate the solenoid, but a lot more power to operate the motor.

 

When you are trying to start a car with a flat battery you can often hear a click.

 

That click is the sound of a solenoid operating despite the fact that there is not enough power available to run the starter motor.

 

I don't want to put words into Richard's mouth, but I suspect that this is why he suspected a flat battery as they symptoms that you describe would be typical of that situation.

 

There are other things that could cause it, of course.

Edited September 8, 2016 by PaulG

[WotEver]

Assuming the thruster has close to 24V on it when the contactor pulls in then it sounds mechanical to me. Maybe shear pin as Nick suggests. That's the most intelligent reply I can come up with but requires some input from OP to check the voltage.

[RLWP]

Because it takes very little power to operate the solenoid, but a lot more power to operate the motor.

 

When you are trying to start a car with a flat battery you can often hear a click.

 

That click is the sound of a solenoid operating despite the fact that there is not enough power available to run the starter motor.

 

I don't want to put words into Richard's mouth, but I suspect that this is why he suspected a flat battery as they symptoms that you describe would be typical of that situation.

 

There are other things that could cause it, of course.

 

Yes, that's what I meant. I'm afraid I don't know enough about your setup to be able to comment on the 'motor runs but no water' issue. I suppose I would want to know that there wasn't something wrapped around the propeller

 

Richard

 

MORE: Is this it?

 

 

http://www.ybw.com/forums/showthread.php?443709-Can-anyone-help-in-identifiying-my-bowthruster

 

Richard

Edited September 8, 2016 by RLWP

[Markinaboat]

Similar Richard. Apologies to all if I ommitted this but Am sure I mentioned sonewhere above that the motor was running for several attempts over a period of time (1.5hrs?) before it then sounded like it was trying to turn. Now, just the solenoids operating The drive chain turns the prop according to the guys yesterday so rhey ruled out the shear pin. Either way, the motor is not now budging at all. 25.7v between solenoid terminal and earth stud.

 

Update. The motor still turns both ways, like a battery is flat, at a snails pace, as thiugh retricted. Coukd it be very slight corrosion/rust on syrfaces of solenoid connections although has always appeared the same when ive made visual inspections.

Edited September 8, 2016 by Markinaboat

[WotEver]

25.7v between solenoid terminal and earth stud.

That's not particularly relevant. What do you have across the motor when a button is depressed?

 

Faulty contactors or low charge on BTs are the most common problems. Sounds like yours may be the contactor.

[Markinaboat]

That's not particularly relevant. What do you have across the motor when a button is depressed?

Faulty contactors or low charge on BTs are the most common problems. Sounds like yours may be the contactor.

Thanks. Will check tonight as casting off now.

[bizzard]

Thanks. Will check tonight as casting off now.

Knitting?

[Tony Brooks]

Similar Richard. Apologies to all if I ommitted this but Am sure I mentioned sonewhere above that the motor was running for several attempts over a period of time (1.5hrs?) before it then sounded like it was trying to turn. Now, just the solenoids operating The drive chain turns the prop according to the guys yesterday so rhey ruled out the shear pin. Either way, the motor is not now budging at all. 25.7v between solenoid terminal and earth stud.

 

Update. The motor still turns both ways, like a battery is flat, at a snails pace, as thiugh retricted. Coukd it be very slight corrosion/rust on syrfaces of solenoid connections although has always appeared the same when ive made visual inspections.

 

Unless they were locking the prop in some way to stop it turning then it may well turn at hand rotate speed but not when it has to produce thrust. If the prop uses a slipping rubber bush instead of a sheer pin then it would certainly turn at hand speed even though the bush is worn.

 

The way you describe the motor turning at normal speed for several operations, then slowing down, then stopping and apparently recovering for a short while makes me suspect a flat battery and I have read the topic from end to end. The way you are releasing information in dribs and drabs and ignoring questions make giving much constructive help impossible.

 

I would be interested to know the voltage when the thruster is actually running or trying to run:

 

1. across the battery lead posts

2. across the battery terminals,

3. across the contactor input terminal

4. Across the motor brushes or the contactor output terminals.

 

That should show up any contactor or battery problems.

[Markinaboat]

Knitting?

No, although I did drop one!

Edited September 8, 2016 by Markinaboat

[Markinaboat]

Tthanks to all for your help, have only jst moord up at Banbury.

 

I gather that if there was a tempray obstruction, then the load could have corroded the terminals.

 

Tony, how do I identify the motor brushes/contactor output terminals (are these on the motor side of the solenoid contacts?)

 

Batteries are fine, Twin Optima AGM's to give 24 volt. Theyre in the engine room and also for starting the 3L2. Cables ae massve, boat built by WFBCO and lsunched in 2002. Subsequently owned by an electrical engineer (Bentley). Elec system is overkill with voltage stabilisers, all MV equipment incl 6kva genny. As previously mentioned, boat was sparceoy used with 1300 hrs on the engine. All in all, a well thought out and efficient system.

 

This was an immedate/sudden change with the BT which is immensely powerful.

 

Apologies if I was a little touchy this morning, bad night and the comment "dont need them etc". They've made a massive didference to my chronic back when mooring up in windy conditions etc.

 

As mentioned earlier, it definitely sounds like its trying to turn but very slowly. Whether the prop is turning I can't say though now its back in the water.

Edited September 8, 2016 by Markinaboat

[WotEver]

Tony, how do I identify the motor brushes/contactor output terminals (are these on the motor side of the solenoid contacts?)

Yep - see what's on those terminals when a button is pressed.

[Markinaboat]

Yep - see what's on those terminals when a button is pressed.

They're the large terminals that I saw 25v on, the large ones on the left but from what others have said above, that's not showing what's getting to the actual motor as they're the solenoid terminals.