VFR has same R/R probs....

[Dave T.]

I was at the electrex site and found this useful info. I thought I'd share. It's the VFR problems link at their web site. Good info!! Vision has the same problems...

VRF Regulator Rectifer Basics
Inside there is a sox diode full wave rectifier, and every phase input can be switched to ground through a thyristor. The thyristors are switched by a regulator circuit that measures the DC output voltage from the rectifier bridge. We call this a shunting regulator. It is a very simple system, and doesn't work very efficient, but it does the job while not dissipating too much heat. That is why all OEM manufacturers still use this setup.

As you know the VFR has a problem in the charging circuit. There are a few reasons for this. First of all the regulator relies on the frame of the bike as it's heatsink. That in itself is not bad, as long as there is good thermal contact between the diodes and thyristors inside the unit to the housing, and as long as there is a good thermal contact between the housing and the frame. If that is taken care of, the heatsinking capabilities are just as good as an RR unit with a large built in heatsink.

The problems in the VFR system is as follows:
Problem #1 is the heatsinking to the frame. Our RR30 replacement unit needs to be mounted using white heatsinking paste, the same stuff that is used in fitting power transistors on cooling elements in amplifiers. We did quite a bit of testing using thermocouples that we built inside the RR before filling it with epoxy. That way you can test the temperature where it is most critical, on the components themselves. Honda should have fitted all their OEM regulator/rectifiers with some of this compound on the back. The RR30 unit also has excellent heatsinking from the components to the housing. That is the main feature in all of our regulator/rectifiers.

Problem #2: The stator is a high power unit. It resides in the heart of the very compact V-4 motor, and therefore it gets quite hot. The stator is used in the CBR models as well, and these bikes also use the same regulator/rectifier. CBR's have far fewer problems using the same setup. My idea is that the main difference is the location of the stator. The CBR is a line engine, and the stator is mounted on the end of the crank. It will not get as hot as the VFR model. Then Honda uses a delta wound stator. The voltage output of this stator is lower that from a comparable star wound unit, and the current output is quite a bit higher.

As you guys also have found out, quite often when a regulator/rectifier fails, a new one will fail after a fairly short time. It is a recurring problem (not on all bikes, but I have seen it quite often). The stator has 18 poles, 6 per phase. Every poles has (I don't know by head exactly) 20 turns of copper wire on it. In between the phase outputs in a delta wound system you will have 120 turns. Because of the hot spot in the engine, the copper winding's insulation starts to fail after some time. Most likely that will be somewhere from  one layer of windings to the next layer on a pole. This usually happens only under load and when the unit is hot.  Imagine a few of these shorts in between the phase outputs. You will have not 120 turns but say 50 or 60. The complete charging system will still be able to reach 14.4 Vdc, it is rated for about 400W.

As you know, when you have a transformer with only a few thick windings, you will get a very low voltage and a massive current output. The same happens in the VFR Delta stator. Those 60 turns will give a much lower Vac but a much higher Iac. And diodes in regulator/rectifiers don't like high currents. If they are rated for 35 Amps (like the ones we use in our RR30's) they can handle that whenever they get sufficient cooling. When they run hot, the max current they can handle drops down quite a bit, which makes dissipate even more heat, and finally one of the diodes fails! The stator we supply for some of the VFR's is wound in star. The total power output is about the same as the original (lower Iac times higher Vac makes about the same... I know this is simplified, there  is more to it....). But there is always two phases in between the phase connections. (=240 turns) The Vac is higher, and the Iac is lower. Even if there would be a short in between some layers of turns (I haven't seen that happen) you still wouldn't have the current output of the original stator, which is what destroys regulator diodes.







So far this (still unproven!) seems correct. It is difficult to prove, as you need to check the original stator for shorted windings whenever the systems is under load, and very hot. And it doesn't need to do it all the time even! Bikes that have had a few failing RR's stopped frying them after replacing the stator.

One last thing:

Problem #3:The output of the RR is fed through the wiring loom and some sort of junction box to the battery. Make sure you have perfect connections here. I found a number of problems with voltage drops over these lines. Check our fault finding chart on http://www.electrexusa.com It will guide you through the process. The best thing to do, if you see any voltage drops in between RR and battery (we are talking high current here, so any bad connection will give a significant voltage drop) is to feed the ouput of the RR straight to the battery terminals using a (good quality) inline fuse.

We hope this information has been helpful to you.


Best regards!



Ritzo Muntinga

[rick_nowak]

so, if i read this correctly, then the only really new thing here is to make sure that one has a tight thermal bond between the rr and the frame, in particular to use dielectric mounting compound between the case and frame mounting points, possibly also removing paint, protruding nibs of whatever on both pieces with a file and ensuring that one has the best possible bond.  sure beats relocation/fans/etc.
it's also good to see from another direction the wisdom of deleting connectors and soldered joints.  
dielectric mounting compound (grease) can be most easily acquired by most people at --Radio Shack--.  cost is 2-3 bucks i think.  usually comes in tubes and you don't need a lot.
now, if one could get ones hands on a star wound stator instead of the more heat prone delta type........

[Dave T.]

One thing though. The Vision has the heat sink "built in" to it. The VFR's doesn't come with heat sink. It mounts to a plate on the side of the bike beneath the right side of the seat.

I am having a problem with my R/R "overcharging" at high rpm's. One thing I figured out this morning it that the brown wire "sensing" wire was at a lower voltage than the red output wire. I found a voltage drop either at the ignition (key) switch, or where the brown wire is tied into the harness (in the headlight bucket?). Since the actual voltage from the brown wire is lower than the actual output voltage (red), the R/R isn't sinking enough current to ground.

Also, the Vision stator is wound in a "Wye" type configuration already (star). ?Delta is wound in a triangle type form.

I thought my red wire was sending back low voltage, but turns out that it was the brown wire.

Another thing I figured out, if one of the diodes in the R/R is "shorted" you will get dead batteries. The diodes in the R/R keep the red +12V from the battery from shorting to ground.

I just though more V owners would like to know more about voltage regulation and possible problems.  ;D

[jasonm.]

Our R/R is mounted to the back of the PLASTIC battery box. Not much of a heat sink there.....

[admin]

thanks for the informative post.
If I get anything out of this that would be helpful
other than the things we are already aware of, it sounds
like one way to improve reliability would be to use a smaller
guage of the wire and increase the number of windings.
can anyone comment on this?

where the r/r already has a heat sink built into it,  relocating
it might help, I have no idea how warm these get other
than catching heat from the exhaust. has anyone put a
temp sensor on one of these while riding to get a sense of this?

-Ron

[Rick G]

In the case of the Vision , moving the RR to a better ventilated location IS   a benefit , the plastic  battery case is only a mounting point , the RR has its own heat sink, unlike the VFR, which depends on the frame  to disipate excess heat.  I think the answer is an oil cooler . We have discussed this befor , but no one , as yet, has come up with any definate information.  

[Cdnlouie]

The RR heats up all on its own real quick, that is probably why most manufacturers hide it.  It is very easy to be burned on a RR (been there done that in my early wrench years) therefore it is a safety hazard on a motorcycle.

The exhaust location justs compounds the issue of the RR being able to do its job.

Thanks for the info D.T.

[ElectWreck]

just a note about wire sizes, etc... the common choices for rewind wire in the US would be 20AWG (.030") or 18AWG (.038").  The difference in cross section is about 50%, quite a bit.  The wire that came off my stator must have been metric, it was between the two above, but closer to the 18AWG.  My bike's stator had about 30 turns on each pole, acutally some poles had one more, some one less, but the total per phase was the same.  I asked a couple of electrical engineers about changing the number of windings and they wouldn't make a recomendation, saying that if the  PIV (Peak Inverse Voltage) was exceeded it would likely break down the rectifier; perhaps the thyristor mitigates the high voltage problem.  The PIV limit is a function of temperature, heat is bad.  

regarding the battery; it is fairly close to the RR in the wiring harness.  The voltage feedback wire senses the voltage in the vicinity of the headlight.  If there is a two volt drop between the source of the feedback wire and the R/R, the R/R will try to compensate for the voltage drop, with the unhelpful side effect of overcharging the battery.

[Lucky]

Then I think the obvious question is why didn't they wire the brown wire directly to the battery (or at least the starter solinoid?)  if this would be a voltage draw, the perhaps we should move the sensing wire to the ignition switch..

[ElectWreck]

I think the feedback wire goes through the switch so that there is no feedback (and thus no drain on the battery) when the key is turned off.

I can see why the wiring diagram was designed the way it is, the real problem is in the materials/connectors used.  They worked ok when they were new, but with age they are highly problematic.  It might not be a bad idea to run 10AWG or 12AWG stranded wire from the R/R to the battery and to the  key switch.  The 60/65 watt headlight power running through the switch can become a problem, so a relay for the headlight would seem appropriate.  Relocating the R/R to an area where it can get better cooling, either through better heat sinking through the frame, or in better airflow as in front of the radiator seems like a good thing to do.

I don't know if the stator went first on my bike and took the R/R with it, or if the R/R went and took the stator; either way, it allowed the battery to drain within a few miles, the headlight drains it fairly quickly.  It was during the day so I couldn't tell that the headlight was also getting dim.  When the water got warm enough to need the fan there wasn't enough power to run the fan.  The reduced voltage made the temp gage run lower than it should, so even though the engine was getting really hot the gage said it was cool.  Then the engine siezed.  Just as I disengaged the clutch the rear wheel locked up.  It was a sad day, it was a long walk home.  It started up again after I recharged the battery, but I'm concerned that I may have scuffed or collapsed a piston.  Yuk!

It's better to keep the electricals in shape.

[jasonm.]

I read Some guys with VFRs have used Processor cooling fans to keep the R/Rs from frying. Idea is to keep the air moving. Just have to find a good way of mounting one.

[Humber]

It will never cool your reg since the rear head dissapates to much heat.

By the way, I moved my reg. to the front last season and after 3 months it died.... so maybe cooling the reg. is another blind alley... probalby won't help with the problem...

[scootertramp]

Problem #3:The output of the RR is fed through the wiring loom and some sort of junction box to the battery. Make sure you have perfect connections here. I found a number of problems with voltage drops over these lines. Check our fault finding chart on http://www.electrexusa.com It will guide you through the process. The best thing to do, if you see any voltage drops in between RR and battery (we are talking high current here, so any bad connection will give a significant voltage drop) is to feed the ouput of the RR straight to the battery terminals using a (good quality) inline fuse.


how would I do this?
 help please?

[Humber]

guys... it is not exactly like that... that's right that an interceptor uses the frame for dissipating heat... but not all of them... 86 VFR is as our V... the RR has fins, the housing may be used as a negative, and there is a brown wire in it for regulating output....

I don't know when was the change but my friend's VFRs failed two times.... an 86 as a first.. and some 3 days ago a '95.

SO... he called me and asked for help since I am in thiss charging stuff all the time... I went there and what I see...

'95 reg is different.... there is no brown on it... so there is an internal regulator in it... housing is not negative.... checked the reg.. burnt... but but


as my friend is green, he suspected alternator and took off the left stator cover...

I was a little bit surprised... because the bike was standing on the left side stand... and the oil level was full... and it didn't spill over the crankcase....

so... my conclusion is that there is either no oil in the VFR's stator while the bike is running or there is small amount of it there.... but sure... less than in a VISION...

I assume that Vision stator is cooled better than interceptor's one... so the reason for stator failure in our bikes must lie somewhere else.... all in all... the newest 02 interceptor uses the same stator... and the design remained the same....

so... the clue is out of there....

[Walt_M.]

Sounds more and more like the connectors are key to the Vision failures. I have redone my AC side and now, I will fix the DC. I have also decided to use crimp type butt splices instead of soldering the connections. I have been using them exclusively in my work in the electrical utility industry and they are quite reliable. My CPU cooling fan on the R/R is still running too but I am thinking about reversing the rotation and/or adding an air duct.

[Humber]

soldering... don't believe... there is a guy DAN BYERS.... he burnt ELECTREX two times...

of course.. it helps.. but I think relocating r/r makes a world of difference...

don't understand me wrong... I know that people over here experience charging problems.... but I am not among them... although I have an original stator on my bike and R/R... (connectors began to melt 2 years ago.. so I soldered and relocated),  she managed to run for 62k km/s without any failure... and at the moment I can't see any reasons to worry...

but... this doesn't change the fact that this bike is a shit in respect of electrical issues..... and I won't change my mind.. I am really scepticall about her and pesimist in general.... it's bullshit when sb says that other bikes have the same problems.... lucky sometimes does;))) A lot of my friends own 20 year old Jap stuff... XJs, CBs, GSFs, Magnas, Sabres, KZ, GPZ the list is looong.... and nobody suffers because of damn charging...

neither do I... but I have to monitor my electricity all the time... and to keep a spare stator while on the way...