Wendell;
If I were doing it over, I’d use
twisted conductor, shielded cable (ground shield at box). I don’t
know that it is needed, but it can help eliminate capacitance coupling and RF
interference. Inductive (magnetic) coupling could still occur, so if you
can separate them by 2-3 inches it would be good. Electrical noise is a
bit of a guessing game, so take this as one of the guesses.
Another opinion: I’d also replace
all the solder socket plugs with the machined, plated, crimp D-sub
connectors. It’s faster, easier, more consistent, eliminates the
potential of flux induced corrosion, and gives you removable pins. I did a
careful soldering job, but used Radio Shack flux core solder; and on careful
examination of connectors done a few years ago there are signs of corrosion. For
thermocouple connections directly to the d-sub, it is necessary; thermocouple
leads do not ‘solder’ unless you use silver solder; which you
really can’t do on the d-sub plug without melting the plastic carrier.
Just my opinions.
Al (still fighting noise issues and a
bad thermocouple connection)
-----Original Message-----
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Wendell Voto
Sent: Saturday, October 07, 2006
8:08 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Latest
EC2 updates, Installation notes
Would
shielded cables be okay to run close together in a fiberglass aircraft?
-----
Original Message -----
Sent: Wednesday, October 04,
2006 9:31 AM
Subject:
[FlyRotary] Re: Latest EC2 updates, Installation notes
While
trouble shooting Al Gietzen's EC2 engine controller problems, he mentioned that
he was seeing relatively large mixture changes when the alternator was
switched off and the battery voltage went low. The mixture goes leaner
with lower battery voltage because the injectors take longer to
open. It was well within the range of the manual mixture control to
correct but it got me to thinking about adding battery
voltage compensation to the EC2. This has been done and all
controllers shipped after 9-20-06 now incorporate this feature. Not a
freebie, but if anyone wants this incorporated into an earlier EC2 it can be
retrofitted.
The
other update is a rev limiter. It was easy to do so I went ahead and added
it. I haven't seen this as a priority because in our application if you make
use of it, it means that you need to be more concerned about the pilot's health
than the engine's (the prop has fallen off the airplane). The default rev
limit is 8000 rpm. If you want something different, specify when
ordering. (Also retrofittable)
EC2 /
EM2 Installation Note.
This
only applies to EC2 engine controller installations combined with early
two-part EM2 engine monitors in canard aircraft where both units are installed
near the engine and have long wiring harnesses connecting them to the EC2 front
panel and EM2 display (a rare combination that may be unique to Al's
airplane). Have been working with Al for some time searching for
the cause of random MAP table and other EC2 parameter corruption. I am
now almost certain that the cause is noise coupling from the EM2 display
harness into the EC2 control panel harness. The two harnesses were
laced together in Al's installation. He is in the process of
separating them now (sympathies to Al, no picnic). Needless to say
at this point, never run these two harnesses together and separate them
as far as practical. I think Al will have about 4 inches between
them when separated.