 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
Dave Saylor
Joined: 11 Jan 2015
Posts: 209
Location: GILROY, CA
|
 Posted: Fri Jul 29, 2016 12:34 pm Post subject: Alternator failure mode |
 |
|
I just finished a leak check after other mx during which the alternator was removed. All went well except I got an over-voltage. I started with the field breaker pulled and before I even checked bus voltage just habitually reset the field. It immediately popped. Then I saw the voltmeter at 18.1 and stable.
I shut down right away. All I could think was that I put the plug on the alternator upside down so I checked that--turns out that's impossible and it was well seated. So I plugged it back in, pulled the field breaker, started the engine. Reset the breaker and everything is normal: I'm seeing 30+ amps at about 14.5V.
Installed:
PlanePower 12V internally regulated 60A.
Knuckolls crowbar overvoltage module
Two things are odd: the field breaker wouldn't reset right away after shutdown. Maybe too hot?
And bus voltage was reading 18V even when the field breaker was popped. How is that possible?
Any comments or explanations?
--Dave
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
_________________
--Dave
KWVI |
|
| Back to top |
|
 |
nuckolls.bob(at)aeroelect
Guest
|
| Posted: Fri Jul 29, 2016 7:44 pm Post subject: Alternator failure mode |
|
|
At 03:33 PM 7/29/2016, you wrote:
| Quote: | | I just finished a leak check after other mx during which the alternator was removed. All went well except I got an over-voltage. I started with the field breaker pulled and before I even checked bus voltage just habitually reset the field. It immediately popped. Then I saw the voltmeter at 18.1 and stable. |
18.1 volts AFTER the breaker popped?
| Quote: | | I shut down right away. All I could think was that I put the plug on the alternator upside down so I checked that--turns out that's impossible and it was well seated. So I plugged it back in, pulled the field breaker, started the engine. Reset the breaker and everything is normal: I'm seeing 30+ amps at about 14.5V. |
I thought PlanePower alternators were fitted
with their own ov protection. Can you share
a schematic of how your alternator is wired?
Are you using the field breaker as an alternator
control switch?
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
Dave Saylor
Joined: 11 Jan 2015
Posts: 209
Location: GILROY, CA
|
| Posted: Fri Jul 29, 2016 8:26 pm Post subject: Alternator failure mode |
|
|
I'll draw up a schematic but it's very standard. The OV module runs the field to ground, as usual.
Yes, the OV continued after the breaker popped. I understand how weird that seems--nothing in the system makes 18V. I'm glad it was just a leak check and I was able to just shut down.
Now, I'm going by the VM in the EFIS. Could be a glitch there but until now the built in VM has always been flawless. And the breaker wouldn't reset so I believe it was in an OV condition. I can download the recoded data from the run.
Yes, the breaker is the only control. Otherwise the alternator comes on with the battery. I had the breaker pulled before start because of of some extended battery-on tests.
Again, it didn't last long but it was very strange to see the OV and the breaker popped--I had to tell myself to shut down instead of analyze, before the magic smoke came out...
--Dave
PS: FWIW in the past I have, um, "tested" the OV module...we have both flavors of GPU in the shop...the OV works great. --d
On Friday, July 29, 2016, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:
| Quote: | At 03:33 PM 7/29/2016, you wrote:
| Quote: | | I just finished a leak check after other mx during which the alternator was removed. All went well except I got an over-voltage. I started with the field breaker pulled and before I even checked bus voltage just habitually reset the field. It immediately popped. Then I saw the voltmeter at 18.1 and stable. |
18.1 volts AFTER the breaker popped?
| Quote: | | I shut down right away. All I could think was that I put the plug on the alternator upside down so I checked that--turns out that's impossible and it was well seated. So I plugged it back in, pulled the field breaker, started the engine. Reset the breaker and everything is normal:  I'm seeing 30+ amps at about 14.5V. |
I thought PlanePower alternators were fitted
with their own ov protection. Can you share
a schematic of how your alternator is wired?
Are you using the field breaker as an alternator
control switch?
Bob . . .
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
_________________
--Dave
KWVI |
|
| Back to top |
|
|
jbsoar(at)gmail.com
Guest
|
| Posted: Sat Jul 30, 2016 12:09 am Post subject: Alternator failure mode |
|
|
Bob-Is there anything worng with using the field breaker as an alternator control switch? Why would anyone ever want to shut off the alternator?
John B
On Fri, Jul 29, 2016 at 8:43 PM, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:
| Quote: | At 03:33 PM 7/29/2016, you wrote:
| Quote: | | I just finished a leak check after other mx during which the alternator was removed. All went well except I got an over-voltage. I started with the field breaker pulled and before I even checked bus voltage just habitually reset the field. It immediately popped. Then I saw the voltmeter at 18.1 and stable. |
18.1 volts AFTER the breaker popped?
| Quote: | | I shut down right away. All I could think was that I put the plug on the alternator upside down so I checked that--turns out that's impossible and it was well seated. So I plugged it back in, pulled the field breaker, started the engine. Reset the breaker and everything is normal:  I'm seeing 30+ amps at about 14.5V. |
I thought PlanePower alternators were fitted
with their own ov protection. Can you share
a schematic of how your alternator is wired?
Are you using the field breaker as an alternator
control switch?
Bob . . .
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)aeroelect
Guest
|
| Posted: Sat Jul 30, 2016 5:46 am Post subject: Alternator failure mode |
|
|
At 03:07 AM 7/30/2016, you wrote:
| Quote: | Bob-
Is there anything worng with using the field breaker as an alternator control switch? Why would anyone ever want to shut off the alternator? |
It's a legacy thing. Since day one, TC aircraft have
had crew operated controls for all power sources. First
as independent switches and more recently as the 'split
rocker' switch.
Unless you've tested all permutations of operating
conditions, sticking with the legacy systems controls
is the least risk approach. But if one can 'live' with
the potential for dealing with an in-flight anomaly
that requires a new way of dealing with things, then
using a breaker as the occasionally operated 'switch'
is a personal choice.
In this case, there appears to be an anomaly that
presented as an alternator/regulator combination
which (1) went ov and (2) failed to shut down when
the ov system operated.
So there are two questions. (1) What are the
physics that explain the observed events and (2)
rational behind a decision to go non-legacy
controls of the electrical system.
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)aeroelect
Guest
|
| Posted: Sat Jul 30, 2016 5:48 am Post subject: Alternator failure mode |
|
|
| Quote: |
Yes, the breaker is the only control. Otherwise the alternator comes on with the battery. I had the breaker pulled before start because of of some extended battery-on tests.
|
Okay . . . it would be a good lick to open the
breaker, clip an ammeter across the breaker,
battery on, engine not running. CONFIRM that
what appears to be field excitation current
is running through the breaker.
| Quote: | | Again, it didn't last long but it was very strange to see the OV and the breaker popped--I had to tell myself to shut down instead of analyze, before the magic smoke came out... |
Good move . . .
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
bakerocb
Joined: 15 Jan 2006
Posts: 727
Location: FAIRFAX VA
|
| Posted: Sun Jul 31, 2016 3:48 am Post subject: Alternator failure mode |
|
|
7/31/2016
Hello John B, You wrote: “Why would anyone ever want to shut off the alternator?”
In order to ensure that their low voltage warning system is working.
The checklist for the shut down procedure at the end of each flight in my EAB KIS TR-1
airplane includes turning the alternator OFF (via a switch in the field breaker line) while the engine
is still running and ensuring that:
1) The flashing light for the low voltage warning system starts flashing.
2) The Garmin GNS 430W and the Garmin GTX 327 transponder keep working normally on battery
power alone.
Item 2 above is essential if I am to return to my home base inside the Washington DC SFRA.
They would also be nice / essential to have on cross country if my alternator failed** and I wanted
to communicate with ATC or a tower prior to making a landing before the battery
ran out of amps.
OC
**PS: In just my small circle of acquaintance pilots I know of two instances (one a type certificated airplane, the other an EAB) where the alternator
stopped working because of interrupted field current. One was a loose wire the other an inadvertent alternator shut down. Neither airplane
was equipped with low voltage warning and the situation was only discovered after the battery ran down and things stopped working.
=====================================
Time: 01:09:06 AM PST US
From: John B <jbsoar(at)gmail.com>
Subject: Re: Alternator failure mode
Bob-
Is there anything worng with using the field breaker as an alternator
control switch? Why would anyone ever want to shut off the alternator?
John B
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
rlborger(at)mac.com
Guest
|
| Posted: Sun Jul 31, 2016 11:26 am Post subject: Alternator failure mode |
|
|
Gents,
I have been using this product (SparkBright Eclipse) to monitor the battery voltage on my Europa for a couple years now and it seems to work great. I have a second one which will be installed on the Little Toot Sport Biplane project which is almost complete.
http://www.sparkbright.co.uk/battery-voltage-monitors.php
Simple Red/Yellow/Green indication. If you see RED, battery is discharging. If you see YELLOW, battery is charged but the alternator isn’t providing sufficient voltage to maintain. If you see GREEN, battery is charged and alternator is providing sufficient voltage to maintain. If you see alternating RED/GREEN you have an over-voltage situation with the alternator/regulator.
It’s a simple two wire install (red & black) and only requires a small hole in the panel for mounting.
I have no interest in the company other than as a satisfied user.
Blue skies & tailwinds,Bob BorgerEuropa XS Tri, Rotax 914, Airmaster C/S Prop (75 hrs).Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP3705 Lynchburg Dr.Corinth, TX 76208-5331Cel: 817-992-1117rlborger(at)mac.com (rlborger(at)mac.com)
On Jul 31, 2016, at 6:45 AM, Owen Baker <bakerocb(at)cox.net (bakerocb(at)cox.net)> wrote:
7/31/2016
Hello John B, You wrote: “Why would anyone ever want to shut off the alternator?”
In order to ensure that their low voltage warning system is working.
The checklist for the shut down procedure at the end of each flight in my EAB KIS TR-1
airplane includes turning the alternator OFF (via a switch in the field breaker line) while the engine
is still running and ensuring that:
1) The flashing light for the low voltage warning system starts flashing.
2) The Garmin GNS 430W and the Garmin GTX 327 transponder keep working normally on battery
power alone.
Item 2 above is essential if I am to return to my home base inside the Washington DC SFRA.
They would also be nice / essential to have on cross country if my alternator failed** and I wanted
to communicate with ATC or a tower prior to making a landing before the battery
ran out of amps.
OC
**PS: In just my small circle of acquaintance pilots I know of two instances (one a type certificated airplane, the other an EAB) where the alternator
stopped working because of interrupted field current. One was a loose wire the other an inadvertent alternator shut down. Neither airplane
was equipped with low voltage warning and the situation was only discovered after the battery ran down and things stopped working.
=====================================
Time: 01:09:06 AM PST USFrom: John B <jbsoar(at)gmail.com>Subject: Re: Alternator failure modeBob-Is there anything worng with using the field breaker as an alternatorcontrol switch? Why would anyone ever want to shut off the alternator?John B
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)aeroelect
Guest
|
| Posted: Sun Jul 31, 2016 2:13 pm Post subject: Alternator failure mode |
|
|
At 02:24 PM 7/31/2016, you wrote:
| Quote: | Gents,
I have been using this product (SparkBright Eclipse) to monitor the battery voltage on my Europa for a couple years now and it seems to work great. I have a second one which will be installed on the Little Toot Sport Biplane project which is almost complete.
http://www.sparkbright.co.uk/battery-voltage-monitors.php |
I ordered one in to play with about ten years ago . . .
maybe more. It performs electrically as advertised
but a bit dim for sunlight visability. They may have
boosted the light output of their LED choices. I'll
suggest good critical review.
The other factor to ponder considers utility. You
generally don't benefit from a green light saying
everything is okay 99.99% of the time. If your
alternator is fitted with ov protection, you'd
never see a red light since the alternator is
brought to heel in tens of milliseconds . . .
whereupon the bus volts drop to battery voltage.
This leaves ACTIVE NOTIFICATION OF LOW voltage as
the only really useful function . . . and you
do want to make sure you're going to see it
under all anticipated lighting conditions.
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
zwakie
Joined: 03 Aug 2009
Posts: 157
|
| Posted: Mon Aug 01, 2016 7:23 am Post subject: Re: Alternator failure mode |
|
|
| nuckolls.bob(at)aeroelect wrote: | | This leaves ACTIVE NOTIFICATION OF LOW voltage as the only really useful function . . . and you do want to make sure you're going to see it under all anticipated lighting conditions. |
Just a FYI: SparkBright can do custom notifications. I will use one in my new panel as well, and I have the same reasoning you have Bob: I will have mine go green once the alternator comes on-line and will dim after 30 seconds, only to start shining once Voltage changes outside the 'green thresholds' (OV, no-charge, etc.).
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
_________________
Marcel Zwakenberg
Europa XS TG || 912ULS || PH-SBR |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
