Adverc/Alternator fault?

[Theo]

Here is a copy of what I sent to Adverc yesterday. They are enjoying their weekend, I suppose, so I thought that I would ask the opinions of the forum

I have had my Adverc since June last year and fitted in in mid July, if I recall correctly.

In the past weeks I have detected what might (or might not be) a problem and would appreciate your advice.

The first thing that I noticed was that my normally reliable BMC 1.5 was surging in revs when on tickover and when running at canal speed. I soon tracked this down to the fact that the alternator was delivering a cyclically varying current.

This afternoon I noticed, while waiting for a lock to fill with the engine on tick over, that the alternator warning light was glowing cyclically while the engine was surging as before. The light's glowing is difficult to observe because the fault is not always there and I cannot predict when it appears. My aim is to unplug the Adverc to see if that makes a difference.

A fact which might be relevant is that the alternator (Bosch 100A) is about 8 years old and has getting on for 5,000 hours running time. I suppose that the brushes could be wearing out. When I fitted the Adverc they looked quite warn as were the slip rings.
I would be interested in hearing your comments.

Regards

What do the cognoscenti reckon?

Nick

[valrene9600]

Cognoscenti! Is that a type of pasta.

[ditchcrawler]

I think I would have just unplugged it and seen what the outcome was.

I have spoken to Adverc a long time ago when I fitted mine, I didn't have an "ignition" light or switch in the circuit and found them quite helpful and happy to discuss things, but that was about 12 years ago.

[MoominPapa]

I have an Adverc fitted and it goes through a phase of cyclic instability as the batteries charge. At the start with deeply discharged batteries it opens up the alternator full-bore. After the batteries get to about 85% and 14.4/14.8v it will start to cycle. Eventually it settles down again as the batteries reach full charge, I don't regard this as a problem. Alternator light does NOT glow though, and only happens at 14.4v charge voltage limit, so your problem may be something else if battery voltage is not there. Worn brushes would be a good guess.

 

MP.

[dmr]

I really think you should actually disconnect the Adverc and see what happens, and also inspect your brushes and slip rings, rather than just telling the people at Adverc about these things.

 

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

[by'eck]

I had similar issue with just one of my Leece Neville alternators when weight on the ignition switch key turned it off. Note I also had an external regulator fitted albeit a Sterling one. The pulsing interval on then off was around 20 seconds. Worked fine when ignition was turned back on though.

[roland elsdon]

you might be looking at this the wrong way. Our alternator light and advec light come on at low revs and need a good burst of revs to extinguish in the am. So it could be the engine surge causing the light to come on rather than alternator load causing the engine to surge.

Alternator is on minimum load at idle unless it is massively geared up, and the alternator would have trouble increasing its output at low revs sufficint to cause a load on a high powered fast idle engine sufficient to surge. If at higher revs the light goes out and the volts rise I at a normal rate it's unlikely to be advec. If in doubt 10 quid meter from halfords napkin to check advec, their check procedure is online in technical specs.

[Theo]

I have an Adverc fitted and it goes through a phase of cyclic instability as the batteries charge. At the start with deeply discharged batteries it opens up the alternator full-bore. After the batteries get to about 85% and 14.4/14.8v it will start to cycle. Eventually it settles down again as the batteries reach full charge, I don't regard this as a problem. Alternator light does NOT glow though, and only happens at 14.4v charge voltage limit, so your problem may be something else if battery voltage is not there. Worn brushes would be a good guess.

 

MP.

 

That's interesting. The signs are similar to yours, apart from the light glowing and that has only happened the once. The cycling has been happening for a while though, but it wasn't always like that. It will be interesting to hear what they have to say about it.

 

On a slightly different tack. I could renew the brushes but I am almost certain that I would have to renew the regulator at the same time. I can't exactly remember but I suspect that the brushes are and integral part of the regulator assembly on the Bosch alternator. I also imagine that even if I could renew the brushes there is still be problem of the slip rings, They will be worn to match the old brushes will there be a problem with bedding in with a new set of brushes on the old slip rings?

 

Nick

[Theo]

I really think you should actually disconnect the Adverc and see what happens, and also inspect your brushes and slip rings, rather than just telling the people at Adverc about these things.

 

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

 

The problem is that the fault is intermittent. The Adverc takes a bit of getting at and by the time it is got at the surging problem has gone away and I have to wait for some days before it appears again. The warning light glowing has only happened once, yeaterday just before a thunderstorm. It didn't happen during the four hours cruising that we did today. There were no locks to negotiate and we only went on to tickover once we had arrived at the mooring. Didn't happen then.

 

I have inspected the brushes. They are worn, as are the slip rings, but I don't know if they are worn enough to cause a problem. Should brushes be changed as a matter of course, before they get badly worn? How many hours would that be, on average?

 

Nick

Edited June 26, 2016 by Theo
Edited to add a bit

[Theo]

I had similar issue with just one of my Leece Neville alternators when weight on the ignition switch key turned it off. Note I also had an external regulator fitted albeit a Sterling one. The pulsing interval on then off was around 20 seconds. Worked fine when ignition was turned back on though.

 

Adverc explicitly say that the engine should not be run with the ignition key turned off. So I don't. Except for an instant when I shut the engine down. I have the habit of turning the key before pulling the stop pull. It's only for an instant to avoid the racket that the warning buzzer makes if the engine stops with the ignition switch still on.

 

N

[rupertbear]

 

Adverc explicitly say that the engine should not be run with the ignition key turned off.

 

 

I'm puzzled by this. Assuming a diesel engine, surely all that the 'ignition' switch does is apply power to the starter solenoid? Why would it need to be on whilst running?

[Theo]

 

I'm puzzled by this. Assuming a diesel engine, surely all that the 'ignition' switch does is apply power to the starter solenoid? Why would it need to be on whilst running?

 

I imagine that it is to do with the energising of the regulator in the alternator which remains functional with the Adverc fitted.

 

N

[ditchcrawler]

 

I'm puzzled by this. Assuming a diesel engine, surely all that the 'ignition' switch does is apply power to the starter solenoid? Why would it need to be on whilst running?

Adverc pick a supply up from there

[rupertbear]

OK, this is specific to Adverc, then? I'm just wanting to make sure that there isn't a gap in my understanding. Does my original question stand?

 

Assuming a diesel engine, surely all that the 'ignition' switch does is apply power to the starter solenoid?

[ditchcrawler]

OK, this is specific to Adverc, then? I'm just wanting to make sure that there isn't a gap in my understanding. Does my original question stand?

 

Assuming a diesel engine, surely all that the 'ignition' switch does is apply power to the starter solenoid?

No it MAY also supply power to the fuel pump and also the engine stop/run control

[rupertbear]

Thanks for that, now happy that there isn't anything I wasn't aware of.

[Theo]

OK, this is specific to Adverc, then? I'm just wanting to make sure that there isn't a gap in my understanding. Does my original question stand?

 

Assuming a diesel engine, surely all that the 'ignition' switch does is apply power to the starter solenoid?

 

It is specific to my setup which includes an Adverc. I am unsure if my worn alternator is upsetting the Adverc or if the Adverc itself is at fault.

 

Today I have been running with the Adverc disconnected and the alternator appeared to be running normally. What I cannot tell is if the alternator is sending spikes through the electrics which is upsetting the Adverc. The only way I could test this is to change the alternator but that seems a rather expensive test. I a wondering if there is anything else I could try.

 

What I did yesterday is take a complete set of test voltages as detailed in the instructions. There are a few odd ones AFAICT but I don't know what they are telling me. I have not yet been able to send them to Adverc for them to comment.

 

Here they are. I use a split charge relay not a blocking diode.

 

Posting them later.

Edited June 28, 2016 by Theo
I will post them later formatting is a problem ATM

[Theo]

 

It is specific to my setup which includes an Adverc. I am unsure if my worn alternator is upsetting the Adverc or if the Adverc itself is at fault.

 

Today I have been running with the Adverc disconnected and the alternator appeared to be running normally. What I cannot tell is if the alternator is sending spikes through the electrics which is upsetting the Adverc. The only way I could test this is to change the alternator but that seems a rather expensive test. I a wondering if there is anything else I could try.

 

What I did yesterday is take a complete set of test voltages as detailed in the instructions. There are a few odd ones AFAICT but I don't know what they are telling me. I have not yet been able to send them to Adverc for them to comment.

 

Here they are. I use a split charge relay not a blocking diode.

 

Posting them later.

 

Here they are! Click on the image so that you can read the voltages.

 

Edited June 28, 2016 by Theo

[sjc]

I am assuming the Adverc replaces the alternator regulator ? In which case it certainly looks like an Adverc fault. Sadly I am not familiar with the cable colours on your chart, could you add signal names so we can see what each one is doing ( eg : main output, regulator feed, ignition lamp etc etc ). The values you say are varying, are they at the 0.5Hz frequency as well ?

[ditchcrawler]

I am assuming the Adverc replaces the alternator regulator ? In which case it certainly looks like an Adverc fault. Sadly I am not familiar with the cable colours on your chart, could you add signal names so we can see what each one is doing ( eg : main output, regulator feed, ignition lamp etc etc ). The values you say are varying, are they at the 0.5Hz frequency as well ?

No it over rides the internal regulator. If you unplug the Adverc the internal regulator takes over again

[MoominPapa]

 

Here they are! Click on the image so that you can read the voltages.

 

Capture.PNG

 

These look to be fine, and doing what ours does too. When the Adverc is active it's increasing the charge voltage from the 14.1 that the alternator supplies to 14.4 which is the lower of the two values the Adverc switches between. I suspect if you watch it for five or ten minutes you'll see it rise to 14.8. The instability of the charge current seems to be characteristic, as I see exactly the same thing: it's interactions between the alternator excitation and load-related changes in engine speed and changes in battery voltage either side of the set point. All of these things have a delay, so you can get small oscillations about the set point. As long as the voltage stays close to the set point, it's not a problem.

 

Check what it looks like when the batteries are heavily discharged. The charge current should be stable then, as it's controlled by the maximum output of the alternator. Also when the batteries are completely charged, as I said, on mine the oscillation settles down again. I suppose it wouldn't matter if it didn't.

 

The only thing that possibly looks odd is the brown/black voltage. Is it really varying that much? The green/black reading implies that you alternator is positive controlled, ie the excitation goes from the D+ terminal via the brown wire to the adverc and then from the adverc via the green wire to the rotor and finally back to negative via the other brush. It's worth checking the brown wire's connection to the D+ terminal and for breaks in the brown wire. Expecially if you don't get the same reading between D+ and black as you get brown/black. The Adverc brown wire should be connected to D+ on the alternator.

 

 

 

MP

[Theo]

The problem is developing. Today the oscillations were sufficiently wild to give a high voltage warning on the Smartgauge (E03. We are on type two batteries.). At the same time it tripped the inverter.

 

I sent the voltage readings to Adverc and Mark soon phoned back and told me that, as MP has said, the voltage readings are fine. He also said that the alternator behaviour is fine. I knew that, certainly on the time frame that I can look at without an oscilloscope. the other thing that he said is that if an Adverc fails, it just stops working in a major way. It doesn't behave like this. He advised me to check the connections and specifically 2 black leads and the brown lead at the alternator, to make sure that the green is not shorting to earth somehow, and the red battery sensor lead is properly connected to the battery.

 

I will do all that soon and let you know how it goes.

 

Thanks for all the comments and help.

 

Nick

[ditchcrawler]

 

the red battery sensor lead is properly connected to the battery.

 

 

Nick

I had problems with an iffy connection there

[MoominPapa]

The problem is developing. Today the oscillations were sufficiently wild to give a high voltage warning on the Smartgauge (E03. We are on type two batteries.). At the same time it tripped the inverter.

 

I sent the voltage readings to Adverc and Mark soon phoned back and told me that, as MP has said, the voltage readings are fine. He also said that the alternator behaviour is fine. I knew that, certainly on the time frame that I can look at without an oscilloscope. the other thing that he said is that if an Adverc fails, it just stops working in a major way. It doesn't behave like this. He advised me to check the connections and specifically 2 black leads and the brown lead at the alternator, to make sure that the green is not shorting to earth somehow, and the red battery sensor lead is properly connected to the battery.

 

I will do all that soon and let you know how it goes.

 

Thanks for all the comments and help.

 

Nick

 

From the voltage readings, look hard at the brown lead, especially of measuring the voltage at the D+ terminal gives different results to the brown lead at the Adverc. See my earlier comments.

 

MP.

[Keeping Up]

These look to be fine, and doing what ours does too. When the Adverc is active it's increasing the charge voltage from the 14.1 that the alternator supplies to 14.4 which is the lower of the two values the Adverc switches between. I suspect if you watch it for five or ten minutes you'll see it rise to 14.8.

The Adverc never gives 14.8 volts, the two voltages are 14.1 and 14.4 (plus or minus temperature compensation) unless you have opened it up and adjusted the potentiometer inside.

 

Nick we once had a similar problem to yours. It turned out that the time constant of the Adverc and alternator just happened to equal the time constant of the alternator and batteries. By the time the Adverc had convinced the alternator that the voltage needed reducing, and the alternator had attempted to reduce the voltage, it was already too low and the Adverc was telling the alternator to increase it again. The result was an oscillation. Adverc technical were unable to understand the issue or suggest a solution. I found that changing either the alternator or the batteries fixed it. I was wondering whether slugging the sense wire with a large capacitor to ground, on the Adverc side of the temperature sensor, might fix it; but by then my batteries had had it so I replaced them and never had a problem again.