 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
bakerocb
Joined: 15 Jan 2006
Posts: 727
Location: FAIRFAX VA
|
 Posted: Sun Oct 15, 2006 8:05 am Post subject: Ground Wire for Starter Contactor |
 |
|
10/15/2006
Responding to an AeroElectric-List message posted by: "Tinne maha"
<tinnemaha(at)hotmail.com>
Hello Grant, Back when I was building my airplane with a stainless steel
firewall I had occasion to do some electical circuit checking with a multi
meter. I was getting some erratic results and eventually came to the
conclusion that there was some sort of self created insulating surface film
on the stainless steel surface.
I could get good consistent meter readings only by specifically piercing
that film with the sharp point of the meter probe.
This led me to the conclusion that just bolting my starter contactor to the
firewall may not give me the best electrical grounding connection. My
starter contactor case is grounded to the brass firewall forrest-of-tabs
through-bolt. Works great.
Maybe some electrical guru on this list can verify or dispute my findings.
OC -- The best investment we will ever make is in gathering knowledge
_____________________________________
AeroElectric-List message posted by: "Tinne maha" <tinnemaha(at)hotmail.com>
Hi List,
I followed the Z-11 diagram for my simple system & see that the starter
contactor has a 'firewall ground'. To me, that means it grounds through the
stainless steel firewall it is mounted on. Indeed, that is what my ohmeter
says & I'm confident it will perform fine (As I'm not flying yet & haven't
quite fired up the engine yet, I haven't actually seen the contactor work)
However, this seems to conflict with the single point ground idea basic to
Bob's philosophy. My starter contactor is the only component of my system
without a dedicated wire running to the forest of ground tabs.
Any experienced advice or opinions on this?
I've been absent the list for a long time & couldn't find anything on this
in the archives. Hope you haven't already gone over it a hundred times.
Thanks,
Grant
| | - 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 |
|
 |
nuckollsr(at)cox.net
Guest
|
| Posted: Sun Oct 15, 2006 1:25 pm Post subject: Ground Wire for Starter Contactor |
|
|
At 12:04 PM 10/15/2006 -0400, you wrote:
| Quote: |
10/15/2006
Responding to an AeroElectric-List message posted by: "Tinne maha"
<tinnemaha(at)hotmail.com>
Hello Grant, Back when I was building my airplane with a stainless steel
firewall I had occasion to do some electical circuit checking with a multi
meter. I was getting some erratic results and eventually came to the
conclusion that there was some sort of self created insulating surface
film on the stainless steel surface.
I could get good consistent meter readings only by specifically piercing
that film with the sharp point of the meter probe.
This led me to the conclusion that just bolting my starter contactor to
the firewall may not give me the best electrical grounding connection. My
starter contactor case is grounded to the brass firewall forrest-of-tabs
through-bolt. Works great.
Maybe some electrical guru on this list can verify or dispute my findings.
OC -- The best investment we will ever make is in gathering knowledge
|
Yup. Surface treatments for stainless -and- aluminums
do NOT make for good electrical connections. In the
big iron birds we "bond" electro-whizzies to the airframe
by cleaning the area around the holes (bonding brush or
scotch-bright pad on your die-grinder) and then using
fasteners capable of generating and sustaining a lot of
force. I'd recommend nothing smaller than 8-32 hardware
for attaching terminals and appliances to the airframe . . .
10-32 is really good. Use all metal locking nuts too.
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 |
|
|
|
|
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
