ALTERNATOR INSTALLATION WARNING

[swift1894]

Just noticed Leece Neville instructions say before installing an alternator, that battery voltage should be charged to above 12.45 volts. If not "Failure to do so could contribute to immediate damage of the alternator"!!!

So if your batteries are flat and you start your engine to recharge your batteries via the alternator.......

[Tony Brooks]

Just noticed Leece Neville instructions say before installing an alternator, that battery voltage should be charged to above 12.45 volts. If not "Failure to do so could contribute to immediate damage of the alternator"!!!

So if your batteries are flat and you start your engine to recharge your batteries via the alternator.......

 

 

I would be interested in Gibbo's comment on this but as far as I am concerned it sounds like a**e covering and possibly slightly dodgy design. Any alternator should be designed to protect itself against producing excess charging current and if it does not then it's a design fault in my book (given adequate cooling).

 

Just think how many of us have at some time managed to discharge the batteries to below that value and how many alternators we ruined when we started the engine. Of course it could mean that Lucas and co produce a better alternator.

[Albion]

I would be interested in Gibbo's comment on this but as far as I am concerned it sounds like a**e covering and possibly slightly dodgy design. Any alternator should be designed to protect itself against producing excess charging current and if it does not then it's a design fault in my book (given adequate cooling).

 

Just think how many of us have at some time managed to discharge the batteries to below that value and how many alternators we ruined when we started the engine. Of course it could mean that Lucas and co produce a better alternator.

 

I would be interested to know how the Leece-Neville knows that it is just installed as opposed to already having been installed and having to charge a flat battery normally. If it is capable of charging a deeply discharged battery in normal use why is it likely to be damaged by a discharged battery in a first time installation?

Roger

[Timleech]

Just noticed Leece Neville instructions say before installing an alternator, that battery voltage should be charged to above 12.45 volts. If not "Failure to do so could contribute to immediate damage of the alternator"!!!

So if your batteries are flat and you start your engine to recharge your batteries via the alternator.......

 

Are these general instructions, or for a specific model? I'm particularly curious because I might need to do exactly what they seem to be warning against, and don't recall seeing anything in the instructions that came with the alternator.

 

Tim

[dmr]

I have read reports of automotive alternators failing when faced with a flat battery but these are (sometimes) only intended to top up the starter battery, and low weight will also be a design target.

A proper marine alternator should be able to handle a large discharged battery bank without overheating, this is after all their purpose in life! and this is why they cost more.

Leece Neville have a good reputation so I would hope that this is an oversight in the documentation rather than a "get out" clause.

 

...........Dave

[swift1894]

Are these general instructions, or for a specific model? I'm particularly curious because I might need to do exactly what they seem to be warning against, and don't recall seeing anything in the instructions that came with the alternator.

 

Tim

 

http://www.prestolite.com/literature/tech/alts/TSB-1132_Installation_Instructions_8LHA-8LHP.pdf

 

page 3 paragraph 3

Edited July 8, 2012 by swift1894

[Timleech]

http://www.prestolite.com/literature/tech/alts/TSB-1132_Installation_Instructions_8LHA-8LHP.pdf

 

page 3 paragraph 3

 

Thanks. I'll try to find out more.

 

Tim

[OldGoat]

Thanks. I'll try to find out more.

 

Tim

 

 

How strange, I'm a great fan of Prestolite / Leece-neville kit as they are mostly heavy duty items.

I used to run a girt big 24V/175 amp alternator and I did some awful things to it -0 and it kept on running.

With the 8LHA models you're getting a lot of power out of a small package - so that may be connected.

 

There used to be an email contact in the UK who can be very helpful. Perhaps Tim know about it.

[Keeping Up]

Just guessing, but is it a first-time-only installation issue, because these alternators are self-exciting (you don't have to switch on an "ignition" switch) so presumably rely on residual magnetism which may be absent in a factory-new model? It really is a guess because I'm not familiar with the workings of these alternators.

[Timleech]

Just guessing, but is it a first-time-only installation issue, because these alternators are self-exciting (you don't have to switch on an "ignition" switch) so presumably rely on residual magnetism which may be absent in a factory-new model? It really is a guess because I'm not familiar with the workings of these alternators.

 

If it's anything along those lines, then there must surely be a risk of damage if the alternator is connected via an isolation switch, if starting the engine after a long idle period. Further info is needed, I shall see what I can discover.

 

Tim

[Albion]

Just guessing, but is it a first-time-only installation issue, because these alternators are self-exciting (you don't have to switch on an "ignition" switch) so presumably rely on residual magnetism which may be absent in a factory-new model? It really is a guess because I'm not familiar with the workings of these alternators.

That sounds a distinct possibility and the instructions cover some that have residual magnetism and those that may not.

Roger

[nb Innisfree]

Perhaps not relevant to OPs prob but our large frame 24v 100A Leece Neville self excited for about 3 yrs before it stopped charging in mid charge! Turned out it was a manual excite model, don't know how it managed all that time, residual magentism I presume. Also this model now comes with a fixed 28v regulator, I was told by an alternator supplier that Prestolite had some fail (burn out I think) due to reg voltage being set too high. Makes me have some doubts about Leece Neville alts.

[swift1894]

Thanks. I'll try to find out more.

 

Tim

 

Saw this in http://www.batteryfaq.org/

 

9.2.13. Alternators are not designed to recharge dead (flat) or frozen batteries because the stator can be burned up or diodes could fail.

 

Maybe that's the reason.

[bowten]

Saw this in http://www.batteryfaq.org/

 

9.2.13. Alternators are not designed to recharge dead (flat) or frozen batteries because the stator can be burned up or diodes could fail.

 

Maybe that's the reason.

That puts the cat amongst the pigeons.

[Timleech]

Just guessing, but is it a first-time-only installation issue, because these alternators are self-exciting (you don't have to switch on an "ignition" switch) so presumably rely on residual magnetism which may be absent in a factory-new model? It really is a guess because I'm not familiar with the workings of these alternators.

 

Yes, that - plus a measure of US-style covering of backsides - is the answer. There are ways and means to get it excited even if the batteries are low.

 

Tim

[Timleech]

Perhaps not relevant to OPs prob but our large frame 24v 100A Leece Neville self excited for about 3 yrs before it stopped charging in mid charge! Turned out it was a manual excite model, don't know how it managed all that time, residual magentism I presume. Also this model now comes with a fixed 28v regulator, I was told by an alternator supplier that Prestolite had some fail (burn out I think) due to reg voltage being set too high. Makes me have some doubts about Leece Neville alts.

 

The adjustable regs have been phased out on some models, because people were setting them to high. They need to be set when the batteries are fully charged, people were setting them before the batts were full with the result that the voltages became much too high as the batteries became near full.

 

Tim

[nb Innisfree]

The adjustable regs have been phased out on some models, because people were setting them to high. They need to be set when the batteries are fully charged, people were setting them before the batts were full with the result that the voltages became much too high as the batteries became near full.

 

Tim

 

Ah that seems to explain things, though I was careful to set voltage when batts were 100% SoC the reg on our first Leece Neville gave up and we only realised after we caught a whiff of electrolyte drifting out on to the rear deck! had to keep to tickover to stay below 29v otherwise it rose to 35ish volts. Fortunately we spotted it in time and I fitted a high voltage warning buzzer after that.

 

One nice thing about these alts is the full output at low revs but a downside is lack of cooling, I must fix up a cooling fan someday.

Edited July 8, 2012 by nb Innisfree

[Gibbo]

I'm still struggling with this one. I can see absolutely no technical reason why a properly designed alternator could "instantly" fail as a result of a low state of charge battery on initial installation. I can see no reason why it could happen on subsequent start ups.

 

In fact, I can see no reason why even a badly designed alternator could fail "instantly" with a low state of charge battery.

 

My gut feeling is that something got lost between the engineering department and the marketing department (not an uncommon occurrence).

 

Leece Neville do produce alternators that are specifically not designed to recharge batteries and I wonder if something has been pasted from the wrong technical sheet into some marketing paperwork.

 

Either way, I think I'd be taking it back as being "not fit for purpose".

[Timleech]

I'm still struggling with this one. I can see absolutely no technical reason why a properly designed alternator could "instantly" fail as a result of a low state of charge battery on initial installation. I can see no reason why it could happen on subsequent start ups.

 

In fact, I can see no reason why even a badly designed alternator could fail "instantly" with a low state of charge battery.

 

My gut feeling is that something got lost between the engineering department and the marketing department (not an uncommon occurrence).

 

Leece Neville do produce alternators that are specifically not designed to recharge batteries and I wonder if something has been pasted from the wrong technical sheet into some marketing paperwork.

 

Either way, I think I'd be taking it back as being "not fit for purpose".

 

I spoke to the local UK agents about this, they said there could be an issue with a new alternator on low batteries failing to self-excite, but they had never come across an alternator failure for that reason. There is a dodge for applying full field to kick it into life, & they offered if I had a particular worry to run one up on the test bench to establish some magnetism in the core. I'm a bit mystified as to why this isn't done routinely in the factory, suggests they are not dynamically tested before they leave.

 

Tim

Edited July 12, 2012 by Timleech

[Gibbo]

I spoke to the local UK agents about this, they said there could be an issue with a new alternator on low batteries failing to self-excite, but they had never come across an alternator failure for that reason. There is a dodge for applying full field to kick it into life, & they offered if I had a particular worry to run one up on the test bench to establish some magnetism in the core. I'm a bit mystified as to why this isn't done routinely in the factory, suggests they are not dynamically tested before they leave.

 

Failure to self excite is definitely a possibility (but it was have to be pretty badly designed to do so). But the link clearly states that it could cause instant damage.

 

The info from your local agent does seem to point to something being lost in translation between different departments.