Received-SPF: pass
 receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com
From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "'Rotary motors in aircraft'" <flyrotary@lancaironline.net>
Subject: NOP  [FlyRotary] Re: Just livid.....but think anyway.
Date: Tue, 28 Jul 2009 08:01:59 -0400
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: 7bit
Thread-Index: AcoPU/8YtmiB/zs5SYivVO7ZNAlWFgAJSUJA
In-Reply-To: <list-3783283@logan.com>
Message-Id: <20090728120132638.TDDU5845@cdptpa-omta02.mail.rr.com>

Chris,

The reason your serial link blew is that it probably tried to provide a path
for electron flow to a ground (when the EC2 lost its intended grounding
wire) - with way too much current for that link to handle.  This flow
consequently blew the fuseable links I believe Tracy now has installed in
the serial link - just to prevent more sever damage to the EC2 from this
type of mishap.


I don't think you need to exhaust yourself looking for hidden gremlins.  The
broken ground wire could indeed have caused the problem.  When you apply
power to a system - four possibilities exist. 

1.  There will be NO path for ground and NO electrons will flow through the
circuit, with no flow - no damage - although the circuit will not work.
 2. The electrons will flow through a designated and planned route in the
circuit as planned and designed for and all is OK
 3.  The electrons will find an unplanned path and flow but do no damage
 4.  The electronic will find an unplanned path and flow causing damage

I think in your case, situation 4 applies.  Even with a few strands of the
ground wire attached it may have provide sufficient flow path to avoid any
damage.  But, once the last strand separated and the ground wire was gone,
then that is probably when the damaged occurred.  Some circuits might be
able to withstand such misrouting, but while circuits with microchips are
quite rugged - they are sensitive to abnormal voltage conditions especially
voltage spikes. This abnormal voltage can result from current flowing where
it should not.  Also even if the current is not high enough to damage a
microchip, the unplanned voltage can cause the microchip to treat it as some
sort of "unplanned" command for it to do something unintended.

Hang it there

Ed


Ed Anderson

Rv-6A N494BW Rotary Powered

Matthews, NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.rotaryaviation.com/Rotorhead%20Truth.htm


-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Christopher Barber
Sent: Tuesday, July 28, 2009 3:21 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Just livid.....but think anyway.

I made it out to the hangar tonight and attempted to reset the EM2.  No 
joy.  It would not reset and I could not get it to accept any changes in 
the MAP table.  It is all flat lined. 

I will likely not get a chance to further investigate wires until I am 
off on Friday.  I did not see anything obvious other than the ground 
wire that was broken but I shall  investigate much  further.  Of course 
I am bothered but perhaps more concerned as to the why.  I do not want 
to send the unit back to Tracy again, just to hook it up and it blow 
again.  As I mentioned, the engine was running really well before I 
started concentrating on the planes finish.  I felt pretty good that 
after a couple of big set backs over the last two year that I was 
finally on track.  As a matter of fact, I felt this has been the first 
time I have actually been able to use the EM2/EC2 as it should be used 
since I can't blame the EC2 for coolant in my rotor housing or bad 
Jeffco in the tanks.

So, to maybe ask a couple of obvious questions....could the one bad 
thick ground wire breaking completely "toast' the EC2?   I  know it is 
difficult to make hard and fast rules, but this seems pretty 
catastrophic for a single wire break. <yikes>  Also, if I change to 
Controller B, will I be looking at the MAP table for the B controller?  
(if this is flagrantly stated in the manual, I have read past it as I 
focused on other issues).  Okay, I have a few more questions, but my 
brain is a bit too fried/disappointed to form them right now. <sigh again>

So, uh, Tracy, do you have an old EC2 laying around I could buy, that 
way I can be trashing/working on one while your repair the other.  I am 
not kidding, you have any old stock of EC2's?

All the best,

Chris
Houston
>

--
Homepage:  http://www.flyrotary.com/
Archive and UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html

__________ Information from ESET NOD32 Antivirus, version of virus signature
database 3267 (20080714) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com

 
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 3267 (20080714) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com