Today's Message Index:
----------------------
1. 06:24 AM - Re: Yak 55M Throttle Cable (A. Dennis Savarese)
2. 01:22 PM - =?utf-8?B?4pigeW91J2xsIGxvdmUgdGhhdCBuZXdz? (heaysr)
3. 04:11 PM - Re: Generator failure/ loss of electrical power (Bitterlich, Mark G CIV NAVAIR, WD)
4. 08:10 PM - Re: Yak 55M Throttle Cable (Roger Kemp)
5. 08:18 PM - Re: Generator failure/ loss of electrical power (Roger Kemp)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Yak 55M Throttle Cable |
Jason,You should check the cable clamps that grip the cable sleeve.=C2- I
f the cable sleeve moves just slightly in the clamps, the cable will not gi
ve you full travel.=C2- There are probably several clamps all the way fro
m the throttle lever forward to and through the firewall.=C2- So be sure
to check every one.=C2- Also make sure the cable is secure from the last
cable clamp (usually at the firewall) and not flexing hardly at all down to
the carburetor attach point.
Dennis
From: Jason . <jason360@hotmail.com>
To: "yak-list@matronics.com" <yak-list@matronics.com>
Sent: Friday, May 12, 2017 10:56 PM
Subject: Yak-List: Yak 55M Throttle Cable
<!--#yiv9785745119 P {margin-top:0;margin-bottom:0;}-->Has anyone ever had
to replace a throttle cable on the Yak 55M? =C2-I have been having an=C2
-erratic throttle lever to power setting issue (lever position not matchi
ng power output). Suspecting the throttle cable is the issue. =C2-Anyone
ever encounter this?
Thank you
Jason
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | =?utf-8?B?4pigeW91J2xsIGxvdmUgdGhhdCBuZXdz? |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Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Generator failure/ loss of electrical power |
There are a couple of folks that have already commented on the proper setting for
the generator voltage, and I want everyone reading this to know that I have
high regard and respect for everyone that commented. They have also said some
very nice things about me, for which I am gratified. This is going to be a
long discussion, so be fore-warned. If you dont like listening to Mark talk,
then just stop right here and discard the message. OK? That should stop some
of the flak from the peanut gallery. Be aware that I rarely write up explanations
like this anymore, so dont worry this is an exception to the rule.
So with that said, there is a part of me that does not even want to discuss this,
but what the heck, I hope I dont lose any friends.
First of all, EVERYBODY is correct in what they said regarding this topic. No
one is wrong. That is kind of a unique situation really, but factually it is
the truth.
First of all, there was a reference to the Yak manuals, and what they say the proper
output voltage of the generator should be set to. Yes, they all specify
over 28 volts DC, and that is for a number of reasons. All of the equipment
in these aircraft, namely engine instruments, voltage inverters for gyros, pitot
heat, radios, and on and on ALL of these things were designed to operate at
the specified voltage of 28 volts, or 28.5 VDC. The original battery in these
aircraft was typically a Nickel Cadmium design, and the charging voltage for
this battery also met the design generator output voltage specified in the publications.
But then these aircraft came to the United States, and people started immediately
pulling out the original NiCad battery (which was pretty much impossible to
maintain) and started replacing it with two 12 volt gel cell batteries. Some
of the really serious aerobatic types installed two very light weight and minimum
capacity batteries, and in my opinion this was a serious mistake. These
batteries combined with the B&C PMG Alternator (the 10 amp version) could combine
to cause serious damage to avionics components, and Ive watched it happen
a few times now, regardless of the warnings I have given to a few owners. Most
of them finally learned, use different batteries (yes, Gel Cell too), but larger,
and with a better alternator like the B&C SK-35, which is a wonderful design
with the LS1A regulator.
Getting back to gel cell batteries. If you read the fine print that usually comes
with these batteries, you will see that they have a MAXIMUM RECOMMENDED CHARGING
CURRENT! Charging current is typically controlled by varying charging
voltage on the fly. One problem the YAK and CJ aircraft do not have an inherent
system for controlling charging current, voltage yes, current no.
So here we have a conundrum. We are installing gel cell batteries that typically
have smaller inherent capacity than what was originally installed. This a
very important point. Further, they are a different TYPE of battery than was
originally installed, and they are supposed to be charged at a lower CURRENT than
what was originally assumed.
So if you leave your voltage set for 28.5 VDC or whatever the Russian manual says,
then it is going to result in a little bit too high of a charging current
for the gel cell batteries as recommended by the manufactuer. This will then
cause the batteries to gas, and once that happens battery capacity diminishes.
Note: Causing a gel cell to gas is bad business. But then to be honest, all
batteries die eventually. You can extend their life by using fancy chargers
like Battery Minders (I like these a lot by the way), which will shoot a short
blast of HF energy around 3 MHz into the battery to help recombine sulfates
back into acid and off the plates but in the end, they all go bad.
The important thing is to know that you need to check them. Five years is indeed
a long time for battery life in these aircraft, but it is feasible if you
have spent a lot of effort watching charging current and using chargers like the
Battery Minder brand.
What is important to understand is the way generators work. A generator has a
plus and minus connection that outputs voltage correct? Yes it does. But when
the generator is not turning, the PLUS connection on it is essentially a dead
short to ground. That is a bad bad thing to have your battery connected to.
If you connect a good battery to a dead short to ground, there is going to be
a lot of current flowing, and fuses will blow, relays will burn out and wires
can melt. It is a very very bad thing.
As a generator starts spinning slower and slower . Like when your M-14P engine
is coming back to idle, it is not spinning fast enough to deliver a voltage higher
than what is in your battery. At that point, current starts flowing BACKWARDS
or IN REVERSE to your generator FROM the battery. The slower the generator
spins, the less voltage it will then produce and the more current will flow
back into the generator from the battery.
The DMR-200 Combined Relay device is put in there to control this situation. Remember
my previous post about the MAIN CONTACTOR RELAY. This relay is what connects
the generator to the main electrical bus of the aircraft, and thus the
battery as well. When current starts flowing backwards into the generator from
the battery, there is a special device called THE REVERSE CURRENT RELAY that
senses this. Once that current gets high enough, it will cause the MAIN CONTACTOR
RELAY TO OPEN (!!!!) thus disconnecting the generator from the rest of
the aircraft. TA-DA! Problem solved! And yes, that is when the Generator light
comes on!
But lets say you have some weak half assed batteries, that you are trying to get
the last bit of life out of, because you are too cheap to buy new ones. Sorry,
sometimes I get carried away, but it is the truth. People have done this
all the time, and I have watched them do it.
Now when your generator slows down, you start getting reverse current, but the
battery is so darn weak, it cannot supply ENOUGH current to cause the reverse
current relay to sense it. Now you start to have a voltage droop in the aircraft.
Voltage goes lower and lower as the weak batteries discharge more and more.
So now instead of a quick disconnect of the generator, you instead get a
lower and lower battery supply voltage to EVERYTHING in the aircraft that is designed
to run off 28 volts. Radios, Transponders, GPSs, you name it. They are
now all being subjected to a lower voltage than they were designed to operate
with. Sometimes they have had enough and fail. Whos fault is that? Yep yours,
the aircraft owner.
So batteries need to be checked. The easiest way is to put a fairly good load
on the batteries and verify that their voltage does not drop too low. If you
are not up for that, then a good idea is to just replace them every few years
and be done with it.
So I took the time to write this. I hope it was useful to you. Feel free to write
me directly if you disagree, or have a technical input that you feel I missed.
I very well could have. This whole thing is like a string of Dominoes
going down, but you need to keep it in mind.
So yes, you can lower the charging voltage to try and limit charging current to
gel cells, but this is also a two edged sword. My input is to leave it where
the manual says it should be set to, use a Battery Minder charger with a sulfate
blaster at 3.4 MHz, and just bite the bullet and replace those batteries on
a regular basis, and dont use itsy-bitsy batteries dumb move Kemo Sabi.
Mark Bitterlich
Whos YAK-50 is probably going up for sale.
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Yak 55M Throttle Cable |
When was the last time the cable was lubricated? With where that cable comes
through the firewall oil along with all sorts of dirt and grass tracts in a
long the cable.
Doc
Sent from my iPad
> On May 13, 2017, at 8:21 AM, A. Dennis Savarese <dsavarese0812@bellsouth.n
et> wrote:
>
> Jason,
> You should check the cable clamps that grip the cable sleeve. If the cabl
e sleeve moves just slightly in the clamps, the cable will not give you full
travel. There are probably several clamps all the way from the throttle le
ver forward to and through the firewall. So be sure to check every one. Al
so make sure the cable is secure from the last cable clamp (usually at the f
irewall) and not flexing hardly at all down to the carburetor attach point.
> Dennis
>
>
> From: Jason . <jason360@hotmail.com>
> To: "yak-list@matronics.com" <yak-list@matronics.com>
> Sent: Friday, May 12, 2017 10:56 PM
> Subject: Yak-List: Yak 55M Throttle Cable
>
> Has anyone ever had to replace a throttle cable on the Yak 55M? I have be
en having an erratic throttle lever to power setting issue (lever position n
ot matching power output). Suspecting the throttle cable is the issue. Anyo
ne ever encounter this?
>
> Thank you
>
> Jason
>
>
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Generator failure/ loss of electrical power |
Doc
Sent from my iPad
> On May 13, 2017, at 6:08 PM, Bitterlich, Mark G CIV NAVAIR, WD <mark.bitterlich@navy.mil>
wrote:
>
>
> There are a couple of folks that have already commented on the proper setting
for the generator voltage, and I want everyone reading this to know that I have
high regard and respect for everyone that commented. They have also said some
very nice things about me, for which I am gratified. This is going to be
a long discussion, so be fore-warned. If you dont like listening to Mark talk,
then just stop right here and discard the message. OK? That should stop some
of the flak from the peanut gallery. Be aware that I rarely write up explanations
like this anymore, so dont worry this is an exception to the rule.
>
> So with that said, there is a part of me that does not even want to discuss this,
but what the heck, I hope I dont lose any friends.
>
> First of all, EVERYBODY is correct in what they said regarding this topic. No
one is wrong. That is kind of a unique situation really, but factually it is
the truth.
>
> First of all, there was a reference to the Yak manuals, and what they say the
proper output voltage of the generator should be set to. Yes, they all specify
over 28 volts DC, and that is for a number of reasons. All of the equipment
in these aircraft, namely engine instruments, voltage inverters for gyros, pitot
heat, radios, and on and on ALL of these things were designed to operate
at the specified voltage of 28 volts, or 28.5 VDC. The original battery in these
aircraft was typically a Nickel Cadmium design, and the charging voltage
for this battery also met the design generator output voltage specified in the
publications.
>
> But then these aircraft came to the United States, and people started immediately
pulling out the original NiCad battery (which was pretty much impossible
to maintain) and started replacing it with two 12 volt gel cell batteries. Some
of the really serious aerobatic types installed two very light weight and minimum
capacity batteries, and in my opinion this was a serious mistake. These
batteries combined with the B&C PMG Alternator (the 10 amp version) could combine
to cause serious damage to avionics components, and Ive watched it happen
a few times now, regardless of the warnings I have given to a few owners. Most
of them finally learned, use different batteries (yes, Gel Cell too), but
larger, and with a better alternator like the B&C SK-35, which is a wonderful
design with the LS1A regulator.
>
> Getting back to gel cell batteries. If you read the fine print that usually
comes with these batteries, you will see that they have a MAXIMUM RECOMMENDED
CHARGING CURRENT! Charging current is typically controlled by varying charging
voltage on the fly. One problem the YAK and CJ aircraft do not have an inherent
system for controlling charging current, voltage yes, current no.
>
> So here we have a conundrum. We are installing gel cell batteries that typically
have smaller inherent capacity than what was originally installed. This
a very important point. Further, they are a different TYPE of battery than was
originally installed, and they are supposed to be charged at a lower CURRENT
than what was originally assumed.
>
> So if you leave your voltage set for 28.5 VDC or whatever the Russian manual
says, then it is going to result in a little bit too high of a charging current
for the gel cell batteries as recommended by the manufactuer. This will then
cause the batteries to gas, and once that happens battery capacity diminishes.
Note: Causing a gel cell to gas is bad business. But then to be honest,
all batteries die eventually. You can extend their life by using fancy chargers
like Battery Minders (I like these a lot by the way), which will shoot a short
blast of HF energy around 3 MHz into the battery to help recombine sulfates
back into acid and off the plates but in the end, they all go bad.
>
> The important thing is to know that you need to check them. Five years is indeed
a long time for battery life in these aircraft, but it is feasible if you
have spent a lot of effort watching charging current and using chargers like
the Battery Minder brand.
>
> What is important to understand is the way generators work. A generator has
a plus and minus connection that outputs voltage correct? Yes it does. But when
the generator is not turning, the PLUS connection on it is essentially a dead
short to ground. That is a bad bad thing to have your battery connected to.
If you connect a good battery to a dead short to ground, there is going to
be a lot of current flowing, and fuses will blow, relays will burn out and wires
can melt. It is a very very bad thing.
>
> As a generator starts spinning slower and slower . Like when your M-14P engine
is coming back to idle, it is not spinning fast enough to deliver a voltage
higher than what is in your battery. At that point, current starts flowing BACKWARDS
or IN REVERSE to your generator FROM the battery. The slower the generator
spins, the less voltage it will then produce and the more current will flow
back into the generator from the battery.
>
> The DMR-200 Combined Relay device is put in there to control this situation.
Remember my previous post about the MAIN CONTACTOR RELAY. This relay is what
connects the generator to the main electrical bus of the aircraft, and thus the
battery as well. When current starts flowing backwards into the generator
from the battery, there is a special device called THE REVERSE CURRENT RELAY that
senses this. Once that current gets high enough, it will cause the MAIN CONTACTOR
RELAY TO OPEN (!!!!) thus disconnecting the generator from the rest
of the aircraft. TA-DA! Problem solved! And yes, that is when the Generator
light comes on!
>
> But lets say you have some weak half assed batteries, that you are trying to
get the last bit of life out of, because you are too cheap to buy new ones. Sorry,
sometimes I get carried away, but it is the truth. People have done this
all the time, and I have watched them do it.
>
> Now when your generator slows down, you start getting reverse current, but the
battery is so darn weak, it cannot supply ENOUGH current to cause the reverse
current relay to sense it. Now you start to have a voltage droop in the aircraft.
Voltage goes lower and lower as the weak batteries discharge more and
more. So now instead of a quick disconnect of the generator, you instead get
a lower and lower battery supply voltage to EVERYTHING in the aircraft that is
designed to run off 28 volts. Radios, Transponders, GPSs, you name it. They
are now all being subjected to a lower voltage than they were designed to operate
with. Sometimes they have had enough and fail. Whos fault is that? Yep
yours, the aircraft owner.
>
> So batteries need to be checked. The easiest way is to put a fairly good load
on the batteries and verify that their voltage does not drop too low. If you
are not up for that, then a good idea is to just replace them every few years
and be done with it.
>
> So I took the time to write this. I hope it was useful to you. Feel free to
write me directly if you disagree, or have a technical input that you feel I
missed. I very well could have. This whole thing is like a string of Dominoes
going down, but you need to keep it in mind.
>
> So yes, you can lower the charging voltage to try and limit charging current
to gel cells, but this is also a two edged sword. My input is to leave it where
the manual says it should be set to, use a Battery Minder charger with a sulfate
blaster at 3.4 MHz, and just bite the bullet and replace those batteries
on a regular basis, and dont use itsy-bitsy batteries dumb move Kemo Sabi.
>
> Mark Bitterlich
> Whos YAK-50 is probably going up for sale.
>
>
>
>
>
>
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|