---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Fri 02/27/09: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:57 AM - Re: Voltage Regulation (Gill Gutierrez) 2. 12:53 PM - Re: Voltage Regulation (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E) 3. 01:34 PM - Re: Voltage Regulation (Gill Gutierrez) 4. 03:43 PM - Re: Voltage Regulation LONG REPLY! (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E) 5. 05:11 PM - Re: Voltage Regulation (TXYak) 6. 08:51 PM - (no subject) (Fixers4you@aol.com) ________________________________ Message 1 _____________________________________ Time: 09:57:41 AM PST US From: "Gill Gutierrez" Subject: RE: Yak-List: Voltage Regulation This maybe generator related. I would check the generator brushes and springs. Make sure brushes are clean, move easily and are seated and brush springs are properly installed. Gill -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of TXYak Sent: Thursday, February 26, 2009 8:05 AM Subject: Yak-List: Voltage Regulation Question regarding Voltage Regulation in a Yak 52. First, this is a project airplane and has not been flown yet in the US. I have gotten it running, but have no voltage regulation. When I first started it, I had the Gen Fail light at low RPM...as I increased power @ 40% the light went out(started charging) Around 45% the Gen Fail light would come back on and pop the overvoltage breaker. I connected a voltmeter to the DMR-200 as I ran it even if I adjusted the regulation screw...I got no change in voltage. Volts increase with throttle until 45%RPM and kicks Gen offline at @30.5 volts. I have tried another voltage regulator(it had been sitting for 6-7 years unused) got the same symptoms. Can anyone recommend more places to look, as most of you have a better understanding of this electrical system than I do. My level of frustration is tempting me to go with a B & C alternator/regulator. Any advice for or against. If there is a problem in the system somewhere elsse...I don't want to start frying B & C's. Thanks, Chris Keating Read this topic online here: http://forums.matronics.com/viewtopic.php?p=232217#232217 Checked by AVG - www.avg.com 06:40:00 ________________________________ Message 2 _____________________________________ Time: 12:53:55 PM PST US Subject: RE: Yak-List: Voltage Regulation From: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" Gill, with respect... If the generator puts out voltage, and the gen light goes out when the engine RPM is increased past 40%, and then the over-voltage circuit breaker pops at 30-31 volts, this is not a brush or spring problem. If the brushes or springs are completely bad, (either / or) you will have no voltage at all out of the generator. If a spring is weak, you will have intermittant voltage. I.E.: It will be turning on and off rapidly. Brushes and springs push against the commutator windings taking the AC output of the windings and essentially giving you a DC output. Thus the brushes and springs are critical to the generator putting out any output AT ALL. This is a regulation problem dealing with the probable loss of field current from the voltage regulator. For a complete understanding of the theory involved here, you might want to check out this site. http://www.rowand.net/Shop/Tech/AlternatorGeneratorTheory.htm Mark Bitterlich -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Gill Gutierrez Sent: Friday, February 27, 2009 12:56 PM Subject: RE: Yak-List: Voltage Regulation This maybe generator related. I would check the generator brushes and springs. Make sure brushes are clean, move easily and are seated and brush springs are properly installed. Gill -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of TXYak Sent: Thursday, February 26, 2009 8:05 AM Subject: Yak-List: Voltage Regulation Question regarding Voltage Regulation in a Yak 52. First, this is a project airplane and has not been flown yet in the US. I have gotten it running, but have no voltage regulation. When I first started it, I had the Gen Fail light at low RPM...as I increased power @ 40% the light went out(started charging) Around 45% the Gen Fail light would come back on and pop the overvoltage breaker. I connected a voltmeter to the DMR-200 as I ran it even if I adjusted the regulation screw...I got no change in voltage. Volts increase with throttle until 45%RPM and kicks Gen offline at @30.5 volts. I have tried another voltage regulator(it had been sitting for 6-7 years unused) got the same symptoms. Can anyone recommend more places to look, as most of you have a better understanding of this electrical system than I do. My level of frustration is tempting me to go with a B & C alternator/regulator. Any advice for or against. If there is a problem in the system somewhere elsse...I don't want to start frying B & C's. Thanks, Chris Keating Read this topic online here: http://forums.matronics.com/viewtopic.php?p=232217#232217 Checked by AVG - www.avg.com 06:40:00 ________________________________ Message 3 _____________________________________ Time: 01:34:45 PM PST US From: "Gill Gutierrez" Subject: RE: Yak-List: Voltage Regulation Mark, The problem originally described was that the generator light went off at the normal point and then came on with increasing RPM, this suggests that brushes may not be making solid contact and should be easily checked as previously suggested. I am not there so the mic (mechanic in command) will have to decide. Gill -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E Sent: Friday, February 27, 2009 1:53 PM Subject: RE: Yak-List: Voltage Regulation MALS-14 64E" Gill, with respect... If the generator puts out voltage, and the gen light goes out when the engine RPM is increased past 40%, and then the over-voltage circuit breaker pops at 30-31 volts, this is not a brush or spring problem. If the brushes or springs are completely bad, (either / or) you will have no voltage at all out of the generator. If a spring is weak, you will have intermittant voltage. I.E.: It will be turning on and off rapidly. Brushes and springs push against the commutator windings taking the AC output of the windings and essentially giving you a DC output. Thus the brushes and springs are critical to the generator putting out any output AT ALL. This is a regulation problem dealing with the probable loss of field current from the voltage regulator. For a complete understanding of the theory involved here, you might want to check out this site. http://www.rowand.net/Shop/Tech/AlternatorGeneratorTheory.htm Mark Bitterlich -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Gill Gutierrez Sent: Friday, February 27, 2009 12:56 PM Subject: RE: Yak-List: Voltage Regulation This maybe generator related. I would check the generator brushes and springs. Make sure brushes are clean, move easily and are seated and brush springs are properly installed. Gill -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of TXYak Sent: Thursday, February 26, 2009 8:05 AM Subject: Yak-List: Voltage Regulation Question regarding Voltage Regulation in a Yak 52. First, this is a project airplane and has not been flown yet in the US. I have gotten it running, but have no voltage regulation. When I first started it, I had the Gen Fail light at low RPM...as I increased power @ 40% the light went out(started charging) Around 45% the Gen Fail light would come back on and pop the overvoltage breaker. I connected a voltmeter to the DMR-200 as I ran it even if I adjusted the regulation screw...I got no change in voltage. Volts increase with throttle until 45%RPM and kicks Gen offline at @30.5 volts. I have tried another voltage regulator(it had been sitting for 6-7 years unused) got the same symptoms. Can anyone recommend more places to look, as most of you have a better understanding of this electrical system than I do. My level of frustration is tempting me to go with a B & C alternator/regulator. Any advice for or against. If there is a problem in the system somewhere elsse...I don't want to start frying B & C's. Thanks, Chris Keating Read this topic online here: http://forums.matronics.com/viewtopic.php?p=232217#232217 Checked by AVG - www.avg.com 06:40:00 Checked by AVG - www.avg.com 13:27:00 ________________________________ Message 4 _____________________________________ Time: 03:43:01 PM PST US Subject: RE: Yak-List: Voltage Regulation LONG REPLY! From: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" Well, as anyone who knows me has learned long ago, I never run away from a good debate. So... That said, Gill, I do not know what you do for a living, but I am a Avionics Field Engineer, and I am darn sure of what I am talking about regarding this problem. Unfortunately what you are passing to this gentleman is still incorrect and it is in fact ill advised. You said: "The problem originally described was that the generator light went off at the normal point and then came on with increasing RPM, this suggests that brushes may not be making solid contact and should be easily checked as previously suggested." You then also said: "I am not there so the mic (mechanic in command) will have to decide." First, you do not need to be an A&P to troubleshoot this. Most mechanics are not familiar with very old design generator systems, and it is a mistake to think that their word is gospel in a situation where they are dealing with a foreign built aircraft that typically they have no experience with. They also have to deal with minimum documentation on the electrical system that usually is written in Cyrillic. Anyone have a local A&P that speaks and reads Russian? Second, your statement of what happened is out of context and incomplete. I have taken this electrical system apart piece by piece and I know every single part and how it works and why it does what it does in ANY situation. I wrote a complete white paper on this system that explains it. So here's the COMPLETE breakdown of the whole problem. READ IT VERY CAREFULLY BEFORE YOU REPLY PLEASE. 1. The generator light is on. He starts the engine. The light remains on at idle. This is normal. 2. The engine RPM is increased. THE LIGHT GOES OUT. This is normal. 3. Now as the engine RPM is increased FURTHER, the generator light COMES ON. In other words, we now have a fault. The only debate here is what caused it to happen... You say it could be brushes or springs. Well.. Read on. 3. As it went higher the OVER-VOLTAGE CIRCUIT BREAKER POPS and the Gen light comes on again. It is SUPPOSED to come on when you have an over-voltage condition. I'll tell you why later. But....Brushes and springs can not cause a generator to put out too much voltage. That is simply IMPOSSIBLE. Let's review using the exact wording taken from the original message. A. He said: "I connected a voltmeter to the DMR-200 as I ran it even if I adjusted the regulation screw...I got no change in voltage." STOP RIGHT THERE! Without going ANY further, just by that one statement alone, he has a voltage regulation problem. BUT, let's go on. B. "as I increased power @ 40% the light went out(started charging" OK, the GENERATOR IS NOW WORKING AND SUPPLYING POWER TO THE AIRCRAFT BUS. C. He says: "Volts increase with throttle until 45%RPM and kicks Gen offline at @30.5 volts." Please pay particular attention to the MEASURED VOLTAGE OF 30.5 VOLTS DC!!!! That is EXACTLY what the system was designed to do. Take the generator output off line if it puts out too much voltage. From the Russian manuals, that is the exact voltage which causes it. But if you are still not convinced, he also says: D. "Around 45% the Gen Fail light would come back on and POP THE OVERVOLTAGE CIRCUIT BREAKER" (emphasis mine) Ah, yeah... That would be what the over-voltage control circuit is designed to do. Pop the breaker, which opens the main contactor, removing generator voltage from the aircraft and protecting aircraft components and avionics from too much voltage. When the generator has uncontrolled regulation, the voltage will increase with RPM. This is why it is highly likely that the problem he has is directly tied to the voltage control rheostat. Any design engineer always puts in over-voltage protection. In the YAK and Sukhoi series of aircraft, this is a big silver box that is constructed so that when the voltage gets up to about 30-31 volts (exactly as he said), an internal circuit breaker that is covered with a little red piece of rubber, POPS and when it does, it opens the circuit to the main contactor relay and removes all generator output from the aircraft. When the main contactor opens, a sense wire goes LOW and this opens another relay behind the instrument panel that TURNS ON THE GENERATOR LIGHT. Again, this has ZERO to do with brushes and springs. By the way, it is very easy to KEEP this circuit operational when installing a B&C PMG or Alternator, or anything else for that matter. This circuit is very reliable and worth keeping. To continue: The generator light is coming on because the main contactor opened after an over-voltage circuit breaker popped, and not because the generator is not putting out voltage, as would be the case if the brushes and springs were bad. No, the generator is working perfectly just putting out TOO MUCH VOLTAGE, which is why it got disconnected from the aircraft power mains. Want to see it happen for yourself? Just like this guy is seeing? Take the middle wire off of your generator in your aircraft. Connect a new piece of wire directly from that middle generator contact directly to the contact marked with the big PLUS (+) sign. Now start your engine. It will do exactly what this mans airplane does. By the way, doing that is not an advised method of testing your generator, but it is done all the time in the field. If you try this, make sure you have all possible switches in your aircraft turned off, because if your over-voltage system happens not to work, you will end up frying all your avionics. Watch your internal voltmeter very closely if you do this. It will go up and down with RPM very rapidly. Like I said, I do not advise this as a normal step by anyone with less than a complete knowledge of how this system works. This test also has no bearing on the present problem. By the way, it is also very doubtful that your mechanic will know anything about a test like this. A&P's are usually very up to date on ALTERNATORS, but not so hot on old generator designs. ANYWAY. Something most people do not know and I will explain here. What does the generator light really tell you? What makes it come on and what makes it turn off? The generator light is simply an indication that tells you the position of the main contactor relay that connects the generator to the aircraft. If that relay is closed, the generator light goes out. If the main contactor relay is open, the generator light comes on. It is that simple. The main contactor relay itself is controlled by a whole SLEW of OTHER factors. Generator voltage, forward and reverse current, and lastly, by over-voltage conditions. However, what it is NOT is any kind of direct indication that the generator is, or is not, putting out voltage. Merely whether a big relay is either OPEN or CLOSED. It can not be used in any way to determine the condition or operation of the generators brushes and springs EXCEPT IF IT IS FLICKERING. In that case, you very well might want to check your brushes and springs. Of course if there is any doubt, I would advise consulting with a Master Russian Mechanic like Vladimir Yatremski. But keep in mind that he often comes to me for help with this system. Mark Bitterlich EA-6B Prowler Field Engineering MCAS Cherry Point NC Yeah, President Obama was here today.... -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Gill Gutierrez Sent: Friday, February 27, 2009 4:34 PM Subject: RE: Yak-List: Voltage Regulation Mark, The problem originally described was that the generator light went off at the normal point and then came on with increasing RPM, this suggests that brushes may not be making solid contact and should be easily checked as previously suggested. I am not there so the mic (mechanic in command) will have to decide. Gill -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E Sent: Friday, February 27, 2009 1:53 PM Subject: RE: Yak-List: Voltage Regulation --> Point, MALS-14 64E" Gill, with respect... If the generator puts out voltage, and the gen light goes out when the engine RPM is increased past 40%, and then the over-voltage circuit breaker pops at 30-31 volts, this is not a brush or spring problem. If the brushes or springs are completely bad, (either / or) you will have no voltage at all out of the generator. If a spring is weak, you will have intermittant voltage. I.E.: It will be turning on and off rapidly. Brushes and springs push against the commutator windings taking the AC output of the windings and essentially giving you a DC output. Thus the brushes and springs are critical to the generator putting out any output AT ALL. This is a regulation problem dealing with the probable loss of field current from the voltage regulator. For a complete understanding of the theory involved here, you might want to check out this site. http://www.rowand.net/Shop/Tech/AlternatorGeneratorTheory.htm Mark Bitterlich -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Gill Gutierrez Sent: Friday, February 27, 2009 12:56 PM Subject: RE: Yak-List: Voltage Regulation This maybe generator related. I would check the generator brushes and springs. Make sure brushes are clean, move easily and are seated and brush springs are properly installed. Gill -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of TXYak Sent: Thursday, February 26, 2009 8:05 AM Subject: Yak-List: Voltage Regulation Question regarding Voltage Regulation in a Yak 52. First, this is a project airplane and has not been flown yet in the US. I have gotten it running, but have no voltage regulation. When I first started it, I had the Gen Fail light at low RPM...as I increased power @ 40% the light went out(started charging) Around 45% the Gen Fail light would come back on and pop the overvoltage breaker. I connected a voltmeter to the DMR-200 as I ran it even if I adjusted the regulation screw...I got no change in voltage. Volts increase with throttle until 45%RPM and kicks Gen offline at @30.5 volts. I have tried another voltage regulator(it had been sitting for 6-7 years unused) got the same symptoms. Can anyone recommend more places to look, as most of you have a better understanding of this electrical system than I do. My level of frustration is tempting me to go with a B & C alternator/regulator. Any advice for or against. If there is a problem in the system somewhere elsse...I don't want to start frying B & C's. Thanks, Chris Keating Read this topic online here: http://forums.matronics.com/viewtopic.php?p=232217#232217 Checked by AVG - www.avg.com 06:40:00 Checked by AVG - www.avg.com 13:27:00 ________________________________ Message 5 _____________________________________ Time: 05:11:56 PM PST US Subject: Yak-List: Re: Voltage Regulation From: "TXYak" Thanks for the replies. I'll follow up on Monday or Tuesday after I get back in town. Chris Keating Read this topic online here: http://forums.matronics.com/viewtopic.php?p=232376#232376 ________________________________ Message 6 _____________________________________ Time: 08:51:45 PM PST US From: Fixers4you@aol.com Subject: Yak-List: (no subject) Hello All, I need to know the width of the Yak 55m landing gear out side to outside? And the width of the horizontal? Thank You all **************A Good Credit Score is 700 or Above. 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