Which alternator for a Yanmar / Barrus Shire 1950?

[Froggy]

Folks, we have a potentially dodgy alternator. I'll know more tomorrow when we've had an electrician take a look.

After resolving an issue with a perished alternator belt a couple of weeks ago (see separate thread) the control panel buzzer started up again this evening and one of the alternator lights was on. It's a Barrus Shire 1950 engine with twin alternators. I think it was the left alt light that came on, although not sure what alternator this would be. This time the belt is intact and we're suspecting maybe one of the alternators has packed up. There is no obvious sign of loose or broken wires, although I'll have another look tomorrow. So, a couple of questions:

 

1. Is there anywhere in particular i should look for broken wires or loose/corroded connections?

 

2. If the alternator has packed up does anybody know what models would be suitable replacements? This is an old engine, from memory i think it went out of production in the early 1990s. A quick internet search suggests it might not be the easiest of jobs sourcing a new alternator, so before i spend more time i thought i'd ask here.

Edited August 27, 2021 by Froggy

[ditchcrawler]

20 minutes ago, Froggy said:

Folks, we have a potentially dodgy alternator. I'll know more tomorrow when we've had an electrician take a look.

After resolving an issue with a perished alternator belt a couple of weeks ago (see separate thread) the control panel buzzer started up again this evening and one of the alternator lights was on. It's a Barrus Shire 1950 engine with twin alternators. I think it was the left alt light that came on, although not sure what alternator this would be. This time the belt is intact and we're suspecting maybe one of the alternators has packed up. There is no obvious sign of loose or broken wires, although I'll have another look tomorrow. So, a couple of questions:

 

1. Is there anywhere in particular i should look for broken wires or loose/corroded connections?

 

2. If the alternator has packed up does anybody know what models would be suitable replacements? This is an old engine, from memory i think it went out of production in the early 1990s. A quick internet search suggests it might not be the easiest of jobs sourcing a new alternator, so before i spend more time i thought i'd ask here.

Depending where your pond is there maybe someone close by who could repair it for you

[Tony Brooks]

Within reason alternator fittings seem to meet a similar standard so given a similar size and output most will fit, it will be possibly having to redo the connections that will be the problem. When my failed I simply took it to the nearest alternator specialist in the nearest large town and they supplied a higher output, suitable replacement.

 

As Brian points out, we can't help with recommendations etc. unless we have a rough location and a photo or two is always better than an engine make because the marinisers may well alter the auxiliaries fitted depending upon price/supply.

 

Check the multiway plug in the main wiring harness if you have one, there may be two, with one closer to the controls.

 

As you have been poking about down there, double-check the connections on the alternators.

[Tracy D'arth]

Phone RCR and they will fit another engine and gearbox.

[ditchcrawler]

3 hours ago, Tracy D'arth said:

Phone RCR and they will fit another engine and gearbox.

Not if its the domestic alternate, they only cover the starter one

[Froggy]

23 hours ago, Tracy D'arth said:

Phone RCR and they will fit another engine and gearbox.  😃

Strewth, that's a bit drastic!  😃

Edited August 29, 2021 by Froggy

[Froggy]

On 28/08/2021 at 07:17, Tony Brooks said:

Within reason alternator fittings seem to meet a similar standard so given a similar size and output most will fit, it will be possibly having to redo the connections that will be the problem. When my failed I simply took it to the nearest alternator specialist in the nearest large town and they supplied a higher output, suitable replacement.

 

As Brian points out, we can't help with recommendations etc. unless we have a rough location and a photo or two is always better than an engine make because the marinisers may well alter the auxiliaries fitted depending upon price/supply.

 

Check the multiway plug in the main wiring harness if you have one, there may be two, with one closer to the controls.

 

As you have been poking about down there, double-check the connections on the alternators.

 

 

Thanks for your advice Tony, and everybody else. I'm unable to attach a photo from my phone at present - file size is too big, I'll have another go from my laptop as soon as i get a chance. I can confirm that the alternator is fecked and will probably go down the route you suggest of taking it to a local refurbisher. I think i know the reason too - rear ventilation grill was badly clogged with small strands of fibre that seem to have come from the insulation around the exhaust manifold (i think) and pipe. This insulation is falling apart, and looks as if it might be made of asbestos or something. How important is this insulation, and what's its main purpose? Is it simply to keep the temperature down in the engine bay?

[Tony Brooks]

38 minutes ago, Froggy said:

 

 

Thanks for your advice Tony, and everybody else. I'm unable to attach a photo from my phone at present - file size is too big, I'll have another go from my laptop as soon as i get a chance. I can confirm that the alternator is fecked and will probably go down the route you suggest of taking it to a local refurbisher. I think i know the reason too - rear ventilation grill was badly clogged with small strands of fibre that seem to have come from the insulation around the exhaust manifold (i think) and pipe. This insulation is falling apart, and looks as if it might be made of asbestos or something. How important is this insulation, and what's its main purpose? Is it simply to keep the temperature down in the engine bay?

 

The insulation is a BSS requirement, apart from PERHAPS helping to stop third degree burns if you fell/tripped gainst those parts that can get red hot in use.

 

Depending upon age, those wrappings may be asbestos, but on more modern boats they will be glass fibre. My advice if you are unsure is to get new non-asbestos wrapping. Soak the existing wrappings until you are sure they are sodden all the way though and then wear a decent face mask and carefully unwrap it, putting it straight into a double plastic bag for disposal.

 

[Froggy]

Thanks Tony. Engine was built somtime in the 1990s i think (Barrus Shire 1950). Is it a BSS requirement in order to stop the risk of the boards above catching fire?

Edited August 29, 2021 by Froggy

[Tony Brooks]

2 minutes ago, Froggy said:

Thanks Tony. Is it a BSS requirement to stop the risk of the boards above catching fire?

 

I doubt it. That would be covered by the inspector looking for signs of heat damage, and it depends upon how close the parts are to the boards. It should go some way to preventing items close to or accidentally coming into contact igniting.

[ditchcrawler]

1 minute ago, Tony Brooks said:

 

I doubt it. That would be covered by the inspector looking for signs of heat damage, and it depends upon how close the parts are to the boards. It should go some way to preventing items close to or accidentally coming into contact igniting.

I think it use to be but was dropped a few years back, not 100% sure

[Tracy D'arth]

With a water cooled heat exchanger exhaust manifold the risk of scorching anything nearby is minimal even without lagging. Its now purely for personal protection in that situation I reckon.

[Froggy]

Ok, thanks for all your help. It's easily checked re BSS i guess. The priority is to get our alternator refurbished or replaced prompto. We dont have any domestic power at all from battery bank now it's been disconnected. I'll keep you posted how things go and post a photo later if possible.

[Tony Brooks]

Just now, Froggy said:

Ok, thanks for all your help. It's easily checked re BSS i guess. The priority is to get our alternator refurbished or replaced prompto. We dont have any domestic power at all from battery bank now it's been disconnected. I'll keep you posted how things go and post a photo later if possible.

Connect a length of the thickest cable you have by you (or buy a decent jump lead set) between the engine battery pos and domestic battery pos and use the engine alternator to charge both banks. Take the cable off as soon as you sotp the engine.

[Froggy]

29 minutes ago, Tony Brooks said:

 

I doubt it. That would be covered by the inspector looking for signs of heat damage, and it depends upon how close the parts are to the boards. It should go some way to preventing items close to or accidentally coming into contact igniting.

 

27 minutes ago, ditchcrawler said:

I think it use to be but was dropped a few years back, not 100% sure

 

17 minutes ago, Tracy D'arth said:

With a water cooled heat exchanger exhaust manifold the risk of scorching anything nearby is minimal even without lagging. Its now purely for personal protection in that situation I reckon.

 

Ok, thanks for all your help. It's easily checked re BSS i guess. The priority is to get our alternator refurbished or replaced prompto. We dont have any domestic power at all from battery bank now it's been disconnected. I'll keep you posted how things go and post a photo later if possible.

 

•  

 

[Froggy]

6 minutes ago, Tony Brooks said:

Connect a length of the thickest cable you have by you (or buy a decent jump lead set) between the engine battery pos and domestic battery pos and use the engine alternator to charge both banks. Take the cable off as soon as you sotp the engine.

 

Thanks, that might be useful at a later date but at the moment the alternator has been removed and both of the alternators plus the water pump work off the same belt.

[Tony Brooks]

1 minute ago, Froggy said:

 

Thanks, that might be useful at a later date but at the moment the alternator has been removed and both of the alternators plus the water pump work off the same belt.

 

Ah, an early tin alternator Shire then. I never could understand why Barrus had abandoned good engineering practice with that design. There is not really enough belt wrap on the pulleys. It was not that long before they did the job properly. From that it makes it very likely that your exhaust wrapping is glass fibre but I would still treat it as asbestos.

 

[Froggy]

Tin alternator? How very, very dare you!

 

😉

 

Yes, i can remember reading some criticism of that design a few years back, possibly on another thread i posted. It works well enough, although the belt needs tightening every few weeks, which may or may not be related - it could just be that the last belt was of poor quality.

[Tracy D'arth]

1 hour ago, Froggy said:

Tin alternator? How very, very dare you!

 

😉

 

Yes, i can remember reading some criticism of that design a few years back, possibly on another thread i posted. It works well enough, although the belt needs tightening every few weeks, which may or may not be related - it could just be that the last belt was of poor quality.

No, the belt has an almost impossible task to drive 3 pullies from 1 with a loading of around 3 HP with only a third of a pully circumference active area.

[Froggy]

Ok, i've managed to edit the file sizes of the pictures i took in order to upload here. The alternator is a Mando brand, this is embossed into the casing at the back; however there is no other information visible regarding a serial number or amp rating. 

I'm taking this to a refurbishment company later today but your advice might help me make a decision as to whether to refurbish or replace it. There's one very similar on eBay rated at 50 amp. That might well be the rating for this one, but i've been led to believe that 50 amps would be insufficient to supply a service battery bank, and if this alternator is actually higher than 50 amps i certainly wouldn't want to downgrade. If this actually was 50 amps though, and we went for, say, an 80 or 90 amp alternative, would there be any downside to doing so? Our system includes a Victron inverter rated at 1500w.

[Tony Brooks]

For many years, 50 amps was enough to power the whole boat. It's only the modern need for a load of electrical gizmos that makes a larger alternator desirable, like your 1500W inverter and all it powers. It comes down to balancing your electrical demand to the bank size and the time taken to recharge the bank to close to 100%. I doubt anyone can give you an answer unless you do a power/energy audit for your specific boat and your specific use of it.

 

If that is a single V belt, then you are limited anyway by the power the belt can transmit. From what you say, you are on the limit now. It maybe time to fit a VSR so you combine the output from both alternators to charge the batteries.

[Froggy]

38 minutes ago, Tony Brooks said:

For many years, 50 amps was enough to power the whole boat. It's only the modern need for a load of electrical gizmos that makes a larger alternator desirable, like your 1500W inverter and all it powers. It comes down to balancing your electrical demand to the bank size and the time taken to recharge the bank to close to 100%. I doubt anyone can give you an answer unless you do a power/energy audit for your specific boat and your specific use of it.

 

If that is a single V belt, then you are limited anyway by the power the belt can transmit. From what you say, you are on the limit now. It maybe time to fit a VSR so you combine the output from both alternators to charge the batteries.

 

But if this is a 50 amp alternator and we opted, say, to replace with an 80 amp one, could that cause problems? For example, would it increase the likelihood of belt squeal/slippage? Or would the regulator compensate accordingly? We're not sure what exactly failed on the alternator at this point, we've been advised it's either the regulator or the coil winding. If the latter, could the coil winding have burned out because too high a demand was placed on it? With our 1500 inverter, we occasionally use a hoover rated at, i think, 1000w and a microwave, rated at 750w. The other high demand item is a 240v fridge, which we only use occasionally. These items aren't usually used at the same time but my other half said she was using the microwave at the same time as the fridge around the same time the alternator failed. Could it be that the coil burned out because too much demand was being placed on it, and if so, would it be better practice in future to run these items without the engine running and then charge the battery bank back up later? As mentioned earlier, after removing the alternator we discovered the vents were badly clogged so this could have contributed to overheating.

Edited August 31, 2021 by Froggy

[Tony Brooks]

8 minutes ago, Froggy said:

 

But if this is a 50 amp alternator and we opted, say, to replace with an 80 amp one, could that cause problems? For example, would it increase the likelihood of belt squeal/slippage? Or would the regulator compensate accordingly? We're not sure what exactly failed on the alternator at this point, we've been advised it's either the regulator or the coil winding. If the latter, could the coil winding have burned out because too high a demand was placed on it? With our 1500 inverter, we occasionally use a hoover rated at, i think, 1000w and a microwave, rated at 750w. The other high demand item is a 240v fridge, which we only use occasionally. These items aren't usually used at the same time but my other half said she was using the microwave at the same time as the fridge around the same time the alternator failed. Could it be that the coil burned out because too much demand was being placed on it, and if so, would it be better practice in future to run these items without the engine running and then charge the battery bank back up later? As mentioned earlier, after removing the alternator we discovered the vents were badly clogged so this could have contributed to overheating.

 

Yes, it is likely to result in more belt squeal and shredding.

 

Regulators have absolutely nothing to do with how much  current an alternator is delivering. In the early stages it's the alternator's maximum output and in the latter sages, when the regulator is controlling the charging voltage, it is the batteries plus any load that are controlling the charging current.

 

If the alternator burned out because of too high a demand, it would be a faulty design, lack of rotational speed, or lack of cooling air. From what you say, it's probably the latter.

 

ALTERNATORS ARE DESIGNED TO LIMIT THEIR MAXIMUM OUTPUT TO A SAFE LEVEL unless the boater fits an add one or charges at too slow a speed.

 

If you run them without any charging, you will deplete your batteries more, possibly shorten their life, and cause a higher charging current when charging starts again. As alternators should self limit for current, it is always best to run such items when the engine is running to minimise the loss of battery life.

 

[Froggy]

10 minutes ago, Tony Brooks said:

 

Yes, it is likely to result in more belt squeal and shredding.

 

Regulators have absolutely nothing to do with how much  current an alternator is delivering. In the early stages it's the alternator's maximum output and in the latter sages, when the regulator is controlling the charging voltage, it is the batteries plus any load that are controlling the charging current.

 

If the alternator burned out because of too high a demand, it would be a faulty design, lack of rotational speed, or lack of cooling air. From what you say, it's probably the latter.

 

ALTERNATORS ARE DESIGNED TO LIMIT THEIR MAXIMUM OUTPUT TO A SAFE LEVEL unless the boater fits an add one or charges at too slow a speed.

 

If you run them without any charging, you will deplete your batteries more, possibly shorten their life, and cause a higher charging current when charging starts again. As alternators should self limit for current, it is always best to run such items when the engine is running to minimise the loss of battery life.

 

 

 

Thanks Tony, your knowledge is much appreciated. Would that additional squeal/shredding only happen if a high demand was being placed on it by too many appliances being run whilst the engine was running? Certainly, before the last belt snapped (and it was at least three years old), the first sign that it needed tightening was what i assume was belt squeal that would then cease after about 5 minutes (except when the belt was very loose). So i guess that our first step is to find out what the failed alternator rating was, and hopefully the refurbisher can tell us this, and then try to either have it repaired or source something with a similar rating? If we can only source a higher amp replacement could we get away without belt squeal if we limit the demand on the current whilst the engine is running?

Edited August 31, 2021 by Froggy

[Tony Brooks]

Not just by too many appliances, also by very discharged batteries.  Belt squeal is actually the belt slipping on a pulley and a sit does so it tends to heat up and the rubber soften, that increases it's "grip" so it stops slipping and thus squealing.

 

Because of the peculiarities of your particular marinsation I can not advise you to fit a larger alternator. You may or may not get away with a larger one, but it is an expensive way to find out it does not work (2 alternators).