Could a sh775 kill a stator?

[DohcBikes]

Dude, the guy is a electrical engineer.

Thats neat. Im not a cabbie but i know how to drive. You know why engineers and those that work in the field often have a hard time getting along? Because one of them thinks they are superior and doesnt consider the person with hands on experience.

Like the solid state power box. Noone wants it because noone needs it. Its overthought. Just like this regrec deal.

Why you all have to be so close minded is beyond me. Keep kicking out double what you should for rrs it doesnt matter to me anymore.

[jsandidge]

Still no facts, but plenty of arrogance. His claims must be true. Might makes right.

[cowboyup3371]

Quit beating around the bush and actually answer the question - what is your proof? Lay it out for all of us to read so we can make an informed decision

Why you all have to be so close minded is beyond me. Keep kicking out double what you should for rrs it doesnt matter to me anymore.

I love how you say we are so close minded but you refuse to do what I asked for. I think you are nothing but hot air.

[mainiac]

So has any one here had a sh 775 fail? I replaced two regulators in three years and this spring installed a 775 with good results. Granted I only put on about 4500 miles this summer.

[Gorminrider]

I currently own four 80s GS and one 70s. I've owned and disposed of more than that many. In the last decade, I've only tested the voltage on one and found that it was charging correctly. I've only had a couple that didn't show indications of overheating at the stator bullet connectors and R/R outlet bullet connector. Some connector cleaning, and connector elimination (I prefer a soldered joint now) and a used Shindengen shunt type R/R off of a Gold wing is all I've ever done. I've never had a stator go bad. I bought a replacement stator once because when I performed tests, I did not have proper connection between the probe and the stator connector.

I believe that some of that is probably luck, but not all of it. It may be a factor that I rarely cruise at over 65 mph, so I'm rarely at the full output of the stator for extended periods. I generally tour on back roads.

Yes, I've seen that too at the bullet ends and I'm a fan of those Goldwing/Silverwing R/R's too... I should have added that I've replaced all batteries and 2 of the original R/R with these old Honda ones, while another bike has been running very well with an R/R replacement the Previous owner had put in...( I keep meaning to write down the model # !!) but I did have to rewind the stator on this particular bike too 6k miles further on...it had actually been repaired by a (quite -clever) bridging of a short! ...but I figure this R/R was put in at the same time as the repair and is working well for me now.

which brings me to that difficulty of analysis:usage. Previous and Present. I don't do much city driving either and it never gets that hot here for long Nor do I run heating accessories or extra loads...so I am not stressing the system except occassionally.

PLUS with three licensed bikes on the road, it's going to take longer to build up the mileage on any one of these rebuilt systems to say exactly what I did that is a fail, longterm.

I'll just keep an eye on my little voltmeter stuck on at the cluster. And every so often I think to put my finger on the R/R....warmish is ok, HOT is bad.

[posplayr]

Thats neat. Im not a cabbie but i know how to drive. You know why engineers and those that work in the field often have a hard time getting along? Because one of them thinks they are superior and doesnt consider the person with hands on experience.

Like the solid state power box. Noone wants it because noone needs it. Its overthought. Just like this regrec deal.

Why you all have to be so close minded is beyond me. Keep kicking out double what you should for rrs it doesnt matter to me anymore.

I started a poll in your honor.

http://www.thegsresources.com/_forum/showthread.php?243944-Series-R-R-installations-at-the-GSR

[roeme]

Loads of insults in here, rather than facts.

Start a technical discussion.

As everyone should know, the increased failures – let's assume for a moment it's real, not just anecdata – seen/reported by Dohcbikes' acquaintances could have a zillion of other causes:

1. Faulty batch (for whatever reason)
2. Counterfeits
3. Incorrect handling during transport (very unlikely)
4. Incorrect application (R/R ratings given by manufacturer differ dramatically between uncooled/cooled application).
5. Principle of operation is worse than Shunt style (this has been hinted at in here)
6. The SH775 isn't engineered well to begin with
7. There's a difference between how Quads are used, and how bikes are used.

Personally, with my limited EE knowledge, I don't understand why 5) even came up. Also, I don't think Shindengen would still exists if 6 were to apply.

Furthermore, I presume that the R/R's on a quad are statistically under more stress compared to a bike; since many quads are used to get various work done (hauling stuff, winching, etc) and spend more time stationary or in a low-speed application.

posplayr already has taken a somewhat scientific approach by polling the GSR about their SH775 experience.

Dohcbikes, can you please provide more data? We're getting nowhere otherwise.

Also; if I understand you correctly, you're saying shunt-style regulation is superior to series style. Can you please elaborate, in a technical fashion please. From what I understand, the regulation used in the SH775 works by triggering SCR diodes at the correct phase angle, until then the stator windings will be left open – as opposed to shunt, where the windings will be essentially short-circuited.

It seems like a total no-brainer to me.

[Gorminrider]

Thats neat. Im not a cabbie but i know how to drive. You know why engineers and those that work in the field often have a hard time getting along? Because one of them thinks they are superior and doesnt consider the person with hands on experience.

Like the solid state power box. Noone wants it because noone needs it. Its overthought. Just like this regrec deal.

Why you all have to be so close minded is beyond me. Keep kicking out double what you should for rrs it doesnt matter to me anymore.

Not at all. I like opinions. I think that bobrogers looking up of a recall (here: http://www.thegsresources.com/_forum...92#post2348892) is useful information - doesn't it specifically apply to your info brother's reasons why they are replacing these (Thanks bob, even if I am on your"ignore list" too.

My brother has been a service writer for a polaris dealership for several years. They replace the exact reg/reg you guys recommend on this site all the time because they regularly fail and ruin stators. it's not any better than any other, and arguably worse. For the past year they have been recommending mosfet regrecs (aftermarket, which is not their norm because they are a dealership) and have concluded that they are superior.

what is your proof? Lay it out for all of us to read so we can make an informed decision

There's plenty of hearsay and "empirical evidence" on this forum . Do you want his brother to certify himself as a Polaris "service writer" to post the same thing?. I can't imagine why DohcBikes makes this up. It is what is for what it is worth.

arguably worse

however, WILL get you into a discussiont and maybe that's what is wanting more..

[posplayr]

There's plenty of hearsay and "empirical evidence" on this forum . Do you want his brother to certify himself as a Polaris "service writer" to post the same thing?. I can't imagine why DohcBikes makes this up. It is what is for what it is worth.

It is pretty clear he is a troll seeking attention. His only evidence is that he changes out parts based on what his brother told him. He probably can't even describe what the differences are between SHUNT,SERIES and MOSFET R/R's!

[cowboyup3371]

There's plenty of hearsay and "empirical evidence" on this forum . Do you want his brother to certify himself as a Polaris "service writer" to post the same thing?. I can't imagine why DohcBikes makes this up. It is what is for what it is worth. however, WILL get you into a discussiont and maybe that's what is wanting more..

He has made a claim they are worse than any other yet hasn't backed it up with proof. Posplayer backed up his initial claims about the SH775 a few years ago with both the high-level expert stuff and actual proof through riding. After several others on this forum supported Posplayer's claims through their own actual experience as written here, more began to use the product and provided proof as to its effectiveness. I personally have seen how well the SH775 works through my own actual experience enough to the point I bought one for my daughter.

Where is his proof to support his claims? Where are the links to the service bulletins or actual reviews of the product failing MORE than a shunt series? He needs to give us something more than wild claims that will refute what many of us already know is true based on our actual experiences.

[tom203]

It is pretty clear he is a troll seeking attention. ...

yes, probably recently lost his job spamming for the clinton campaign- needs new outlet for his hostility.

[Gorminrider]

http://www.thegsresources.com/_forum/showthread.php?243915-Could-a-sh775-kill-a-stator&p=2349127#post2349127

From what I understand, the regulation used in the SH775 works by triggering SCR diodes at the correct phase angle, until then the stator windings will be left open – as opposed to shunt, where the windings will be essentially short-circuited.

Well, to me it's not a no-brainer. I just vaguely remember reading my audels book and I skipped the hard bits but I've a vague troubleI have with the series-type R/R's... collapsing fields . Everytime the "circuit" opens the counter-field generated by the current produced cutting flux collapses- just a bit like an ignition coil...(and I am not the expert to judge the consequence of this-something about eddies and such producing heat in the armatures...? but you can see the voltage spikes in posplayers pdf. They have to go somewhere. You can't cut off power to a coil without consquence....

Per the shunt-type, it seems to me they are not "short circuited".because the stator itself has no circuit except through the R/R. . The shunting R/R is "the load". I imagine a lightbulb replacing it.... Will my stator burn out in this scenario? Taken alone, It should not....So,why do some R/Rs burn out? The speed at which they turn off and on is part of it(especially the old ones) and so...FETs versus a plain SCR which I guess tends to get stuck half way through full conduction by the rapid cycling and thereby heats up too much.... But it's true the stator is "producing" and has resistance(inductance) in it's windings as part of the circuit...it just gets sooo complicated to add the heating in the armature itself, eddy currents and the actual engine heat from the nearby 40-90 hp mill it's attached to...(that mill is the largest heater in the area and deserves a little more "credit" I think )

But against my misgivings and my guesses are all your experiences and maybe I'll get one too, down the road.

[posplayr]

http://www.thegsresources.com/_forum...27#post2349127



Well, to me it's not a no-brainer. I just vaguely remember reading my audels book and I skipped the hard bits but I've a vague troubleI have with the series-type R/R's... collapsing fields . Everytime the "circuit" opens the counter-field generated by the current produced cutting flux collapses- just a bit like an ignition coil...(and I am not the expert to judge the consequence of this-something about eddies and such producing heat in the armatures...? but you can see the voltage spikes in posplayers pdf. They have to go somewhere. You can't cut off power to a coil without consquence....

Per the shunt-type, it seems to me they are not "short circuited".because the stator itself has no circuit except through the R/R. . The shunting R/R is "the load". I imagine a lightbulb replacing it.... Will my stator burn out in this scenario? Taken alone, It should not....So,why do some R/Rs burn out? The speed at which they turn off and on is part of it(especially the old ones) and so...FETs versus a plain SCR which I guess tends to get stuck half way through full conduction by the rapid cycling and thereby heats up too much.... But it's true the stator is "producing" and has resistance(inductance) in it's windings as part of the circuit...it just gets sooo complicated to add the heating in the armature itself, eddy currents and the actual engine heat from the nearby 40-90 hp mill it's attached to...(that mill is the largest heater in the area and deserves a little more "credit" I think )

But against my misgivings and my guesses are all your experiences and maybe I'll get one too, down the road.

The SERIES regulation strategy uses something called Synchronous rectification, which means that it operates in sync with the AC waveform. The frequency changes with RPM so it needs to keep track of that RPM and phase of the AC waveforms.

The current is also AC and you will notice that in most of the plots of the Compufire, the current is switched off at zero crossings of the current minimizing any L dI/dt (inductive) transients because a switch from zero amps(closed loop) to zero amps(open loop) has an dI/dt=0.

The voltage goes way up because it is open loop but it is also associated with zero current. When the switches are closed (through the dynamic rectification process) the stator output is tied to the battery voltage which tends to limit how high the stator voltage can go.

And yes the SHUNT type R/R literally shorts the stator legs(with an SCR or MOSFET depending on which is being used) . If you want to try it, short all three stator legs together and take a ride on your bike. You will fry the stator.

You could do the same thing with you house wiring, stick a penny into the fuse box, so it wont blow and short out one of your house outlets. The wires in the house will fry.

The things that most people miss is that the PM alternator is a essentially a constant AC current source once you get over say 3K RPM.
The power dissipated in the statro is based on Ohms law P=I^2xR . It is entirely possible that if there are enough conductive cooling paths , and oil to keep the statro in thermal equilibrium then you will get a relatively constant heat output from the stator.

But here is the rub, if the temperature of the stator, rises so to does the resistance of the wire in the stator and so it produces more power which makes it hotter which increase the temperature still further. It is basically an unstable process limited only by the engines ability to absorb and expel that heat.
I think this is teh primary reason for teh separation in experience that people have. People with big CC bikes that ride them hard burn up stator , like people with small CC bikes that run then flat out all the time do as well.

Some people with 750/850 that ride more reserved are probably the ones with the best stator reliability using SHUNT r/r's.

I know that putting a oil sprayer onto the stator reduced engine oil temperature in my 1166.

[Gorminrider]

posplayer-yes, I had to go off and think about that but,I was wondering per the 0 current from your pdf (ssr_VS fh012aa) where it shows the current drops instantly to 0..., it does this because...

The SERIES regulation strategy uses something called Synchronous rectification, which means that it operates in sync with the AC waveform. The frequency changes with RPM so it needs to keep track of that RPM and phase of the AC waveforms.

I didn't know they did that though it's plain enough from your pdf, now you mention it.

I don't see where the "collapsing field" goes( but come to think on it) it is much weaker than I am thinking because , there aren't really enough windings to produce a powerful spike are there?- and is simply cancelled/merged ... I was supposing that was the spike I see in your pdfs but apparently not....

And yes the SHUNT type R/R literally shorts the stator legs(with an SCR or MOSFET depending on which is being used)

but isn't there a voltage drop across the regulator? across all these "semiconductors?" a bit more than 1/2 a volt I figure each one to be when charging or applied to the bikes demands... concurrent so to speak with the shunting, ( a separate stage from rectification as I understand it from diagrams I have ? ) so it has to be a larger portion of total DC Voltage, not just the half volt mentioned in rectification...with the other portion being across the stator..

If you want to try it, short all three stator legs together and take a ride on your bike. You will fry the stator.

actually, this very experiment IS on my list.. I will sooner or later get a spare not-too-bad one and finish it off this way! I guess I'll have to, to be "satisfied".

I know that putting a oil sprayer onto the stator reduced engine oil temperature in my 1166.

Yes! I read that with interest. I am seriously toying with the idea that a large heatsink on the casing might help if it didn't interfere with my gearshift!

[posplayr]

posplayer-yes, I had to go off and think about that but,I was wondering per the 0 current from your pdf (ssr_VS fh012aa) where it shows the current drops instantly to 0..., it does this because...

I didn't know they did that though it's plain enough from your pdf, now you mention it.

I don't see where the "collapsing field" goes( but come to think on it) it is much weaker than I am thinking because , there aren't really enough windings to produce a powerful spike are there?- and is simply cancelled/merged ... I was supposing that was the spike I see in your pdfs but apparently not....

but isn't there a voltage drop across the regulator? across all these "semiconductors?" a bit more than 1/2 a volt I figure each one to be when charging or applied to the bikes demands... concurrent so to speak with the shunting, ( a separate stage from rectification as I understand it from diagrams I have ? ) so it has to be a larger portion of total DC Voltage, not just the half volt mentioned in rectification...with the other portion being across the stator..

actually, this very experiment IS on my list.. I will sooner or later get a spare not-too-bad one and finish it off this way! I guess I'll have to, to be "satisfied".

Yes! I read that with interest. I am seriously toying with the idea that a large heatsink on the casing might help if it didn't interfere with my gearshift!

Current can't stop instantly, if it did V = L dI/dt (time derivative), voltage, would have to be infinite. ; where did you see that?

AC current cycles go through zero twice per cycle. If you open the loop at zero current there is no voltage spike.

The voltage regulator is the short and yes that short might be a small voltage (less than 0.5V) but that is why the R/R gets hot.

Each stator leg, in 120 degrees of succession, generates it's AC waveform( due to mechanical phasing of rotor magnets and the stator poles). Just because you tie two legs of the stator together does not stop the current (look at the current measurements while the MOSFET SHUNT FH012AA R/R is shorted) in either leg and does not mean there is zero voltage across either leg. The sum of the legs is zero(of the voltage in the R/R short), but not each individually. Assuming a Wye configuration, during the short that floating neutral is nowhere near ground anymore.

If you measured Leg to neutral to would not see zero on any leg if there is current flowing. You would need to solder a wire to this point to be able to make this measurement.

As the engine rotates, a portion of that mechanical power is converted to electrical power through the PM alternator. This assumes there is current flowing. If you open the circuit, then there is no current flow and there is no power lost/generated. You allow current to flow and there is power conversion and the stator and the R/R get warm due to the resistive components of their respective reactant.