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BARRY CHECK 6
Joined: 15 Mar 2011 Posts: 738
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Posted: Sat Oct 13, 2018 10:40 am Post subject: B lead circuit breaker |
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OMG!!!
On Wed, Oct 10, 2018 at 10:23 PM Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
Quote: | If I had to put a number to it, 90% were due to bad contacts due to
corrosion.
You can not visually inspect a ground connection. It must be undone, wire
brushed,
NEW star lock washers replaced and tightened securely... Yes, tightened
even
beyond specs. Then, you can spray some chromate paint over the connection
for a bit more corrosion protection.
I've never seen this kind of effort expended on a ground
to the airframe. A bizjet has HUNDREDS of such grounds.
Barry - And this is a plane that you did design work on? What about Ground
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Loops?
You do recall it was Ground Loops that initiated our rivalry .
All are made up with flat and clean faying surfaces assembled
Quote: | to the proper compression specs (torque). The natural
crush that occurs in the terminal creates the gas-tight
*** Barry - This is an after thought - I'm coming back to this point after
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I re-read my remarks on 'That are being CURED...' I just realized I said
use a New Star Washer. Well a Star Washer will NOT permit the type of
joint you are theorizing about. AIR and MOISTURE will get under, around
and between the Star Washer and the Ground Connection. So, that alone
blows your NO AIR ACCESS theory out of the air and right onto the water.
But, continue to read.
It is also a GREAT reason to use Chromate Paint or Dielectric Grease.
Quote: | interface that excludes moisture+air; hence corrosion.
Barry - Are you REALLY comparing a bizjet to what we fly?
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And how many hours a year does a bizjet fly compared to what we fly
And what happens with the bizjet when it is not being flown?
Stored in a heated hanger?
And what 'faying' surface are you talking about? Look up the definition of
faying.
These are Grounding Points, not assembly points.
And that are not on bizjets.
And how may bizjets do you inspect a year?
Me. NONE!
But I do about 30+ GA aircraft a year.
30 aircraft that do not fly more than 100 hours a year.
30 aircraft that do not sit in a heated hangers.
30 aircraft that where most of them spend their ENTIRE LIFE sitting outside
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ronburnett(at)charter.net Guest
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Posted: Sat Oct 13, 2018 6:28 pm Post subject: B lead circuit breaker |
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It has been a week since weather/maintenance has allowed a flight. I have checked connections to the Field CB and Strobe 10 amp auto fuse and all are secure and normal. I will check Ground connections also. My normal loads are 12.5 amps and strobes and wigwams double that if both on. They were all on the first trip, then only strobes the second and last. After that I left all lights off for remainder of nearly 4 hours back home.
Others have complained about Plane Power alternators tripping CB I have recently learned. Vans suggested trying to download some electrical info from my GRT EFIS, which I don’t know how to do.
Appreciate all the help.
Ron Burnett
RV-6A O360 dual EFII
May you have the Lord's blessings today!Sent from my iPad
On Oct 9, 2018, at 8:14 PM, Charlie England <ceengland7(at)gmail.com (ceengland7(at)gmail.com)> wrote:
Quote: | Ken,
We started with the thread being mis-titled, and wrong terms being used. Here's the deal. If his alternator has crowbar style overvoltage protection, *and* its regulator is having a hard time 'tracking' sudden changes in current demand, what could be happening is this: When the strobe is operating, current demand can go from zero to fairly high, and back to zero with the flashing of the strobe. If the regulator can't track the sudden change from high current to near zero current, then alternator output voltage can spike high enough to trip the overvoltage protection circuit. When it trips, it 'crowbars' (shorts) the field supply line to ground. This causes a current spike that exceeds the field circuit breaker (mis-titled as 'B-lead circuit breaker') rating, tripping the breaker and shutting down the alternator.
If I were the OP, I'd try a flight with a lot of electrical loads on the alternator, so that the fluctuating strobe load is only a small percentage of total load. If the nuisance trip disappears, it would seem likely that he has a regulator problem.
Charlie
On 10/9/2018 7:25 PM, Ken Ryan wrote:
Quote: | Thanks Joe. That's what I thought, but an earlier post alluded to voltage causing breaker trip. --Ken
On Tue, Oct 9, 2018 at 4:19 PM user9253 <fransew(at)gmail.com (fransew(at)gmail.com)> wrote:
Quote: | --> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com (fransew(at)gmail.com)>
Circuit breakers trip due to excessive current. Depending on the circuit breaker design, excessive heat can also trip a circuit breaker. That heat could be due to a loose terminal on the circuit breaker. High voltage could indirectly trip an alternator-field breaker if an over voltage protection device shorts to ground, thus causing excessive current.
--------
Joe Gores
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cluros(at)gmail.com Guest
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Posted: Sat Oct 13, 2018 7:22 pm Post subject: B lead circuit breaker |
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"download some electrical info from my GRT EFIS, which I don’t know how to
do "
If you have a USB stick plugged into your EFIS, then you will need to do
the following in order to record the info:
8.3.3 USB Flight Data Logger- “Black Box” feature
The USB Flight Data Logger feature was designed to provide
a seamless recording of a limited number of important flight data
parameters that are continually
written to the USB stick.
Go to SET MENU > General Setup > Demo Settings. Press the knob to open the
page.
USB Flight Data Logger -- On/Off. When On, the Mini will record data when
any of these
are true: airspeed is valid (above the sensor minimum), ground speed is
above 5 knots, RPM/N1
input is non-zero, fuel flow is non-zero.
USB FDL Record Interval (ms) -- Data samples are recorded at this interval:
200 - 30000 ms
in steps of 200 ms. Default is 1000 ms.
USB FDL Save Interval (s) -- The recorded data is written to the USB flash
drive at this interval.
0 - 300 seconds. Default is 60 seconds. (If set to zero, the file is only
written when the internal
buffer fills up or the data logger stops.) For a more continuous black-box
recording, set it to
5 seconds or less.
The data is saved as a .CSV file on the USB stick called “GRT Flight Data
Log.csv and can be opened
and studied using any spreadsheet program.
Then just upload the .csv files from the USB stick to savvy
https://www.savvyanalysis.com/ and have a look at your VOLTS and AMPS
graphs.
On Sat, Oct 13, 2018 at 7:32 PM Ron Burnett <ronburnett(at)charter.net> wrote:
[quote] It has been a week since weather/maintenance has allowed a flight. I have
checked connections to the Field CB and Strobe 10 amp auto fuse and all are
secure and normal. I will check Ground connections also. My normal loads
are 12.5 amps and strobes and wigwams double that if both on. They were all
on the first trip, then only strobes the second and last. After that I
left all lights off for remainder of nearly 4 hours back home.
Others have complained about Plane Power alternators tripping CB I have
recently learned. Vans suggested trying to download some electrical info
from my GRT EFIS, which I don’t know how to do.
Appreciate all the help.
Ron Burnett
RV-6A O360 dual EFII
May you have the Lord's blessings today!
Sent from my iPad
On Oct 9, 2018, at 8:14 PM, Charlie England <ceengland7(at)gmail.com> wrote:
Ken,
We started with the thread being mis-titled, and wrong terms being used.
Here's the deal. If his alternator has crowbar style overvoltage
protection, *and* its regulator is having a hard time 'tracking' sudden
changes in current demand, what could be happening is this: When the strobe
is operating, current demand can go from zero to fairly high, and back to
zero with the flashing of the strobe. If the regulator can't track the
sudden change from high current to near zero current, then alternator
output voltage can spike high enough to trip the overvoltage protection
circuit. When it trips, it 'crowbars' (shorts) the field supply line to
ground. This causes a current spike that exceeds the field circuit breaker
(mis-titled as 'B-lead circuit breaker') rating, tripping the breaker and
shutting down the alternator.
If I were the OP, I'd try a flight with a lot of electrical loads on the
alternator, so that the fluctuating strobe load is only a small percentage
of total load. If the nuisance trip disappears, it would seem likely that
he has a regulator problem.
Charlie
On 10/9/2018 7:25 PM, Ken Ryan wrote:
Thanks Joe. That's what I thought, but an earlier post alluded to voltage
causing breaker trip. --Ken
On Tue, Oct 9, 2018 at 4:19 PM user9253 <fransew(at)gmail.com> wrote:
>
>
> Circuit breakers trip due to excessive current. Depending on the circuit
> breaker design, excessive heat can also trip a circuit breaker. That heat
> could be due to a loose terminal on the circuit breaker. High voltage
> could indirectly trip an alternator-field breaker if an over voltage
> protection device shorts to ground, thus causing excessive current.
>
> --------
> Joe Gores
>
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