Today's Message Index:
----------------------
1. 10:24 AM - Re: Coiled ignition systems (Robert L. Nuckolls, III)
2. 10:28 AM - Re: Re: Hourmeter / oil pressure switch (Robert L. Nuckolls, III)
3. 01:03 PM - Re: Coiled ignition systems (Larry Mac Donald)
4. 05:04 PM - Re: Coiled ignition systems (Robert L. Nuckolls, III)
5. 05:31 PM - Re: Coiled ignition systems (user9253)
6. 05:40 PM - Re: Coiled ignition systems (Larry Mac Donald)
7. 07:44 PM - Z16 Rotax 912 problem (romaja)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Coiled ignition systems |
I would (ass u me) that the manufacturer's specs on installation of
an electronic ignition would spec wires to handle the maximum current
draw of the unit under all operating conditions.
Actually, the manufacture should be silent on
the matter of wire sizes and protection OUTSIDE
their product's boundaries.
The classic interface specification for aircraft
hardware speaks to a 'box' . . . some kind of device
or collection of devices with goesintas and goesoutas.
I.e. you supply operating energy and control command
inputs to effect the specified result whether that's sparks,
noises from the headphones, or fluid flows to the engine
as outputs.
You also list limits for which the product is designed
and tested to tolerate which included but are not
limited to performance, extraordinary demands, environment,
etc.
This philosophy offers a set of conditions that are
easily verified during qualification and manufacturing
in the laboratory environment. This is how we get the
'good housekeeping seal of approval' on the various
mechno and electro-whizzies totally independent of
the products ultimate application.
It is up to the system designer to evaluate capabilities
and limits for the sub-system for suitability to task
in the super-system. This would include a failure mode
effects analysis and characterizing the risks to
aluminum and body parts should expectations not
be realized.
The fire-fighting pump narrative is interesting . . .
it was probably the sum total of regulatory effects
for two or more committees . . . who don't talk
to each other . . . never had to fight a fire . . .
and don't do system integration tasks aided by
thoughtful FMEA.
In the case of our single Kettering ignition system,
exactly what kind of fault might we suppose would
demand an extra-ordinary amount of energy yet
have no effect on normal or even crippled
operation of the ignition system?
Get out your hammers, picks, soldering irons . . .
any tool of your choice and create a fault within
the system that falls within the scenario of
concern.
In the case of single, battery-powered Kettering
(or even more modern automotive) ignition systems,
we're evaluating the same risks tackled by
all auto-conversion configurations since
the DH Pietenpol bolted the model A engine
into the Air Camper.
http://tinyurl.com/jxctbso
http://tinyurl.com/z5syrtf
Interestingly enough, the model T engine was
wwaayyyy ahead of its time. Like modern automobiles,
each spark plug enjoyed its own, dedicated ignition
coil. This offered some level of failure tolerance
for the coils each of which behaved much like the
'shower of sparks' system and featured its
own set of vibrator points and 'condenser'.
[]
The fundamentals for storing energy on an
inductor, using 'transformer action' of a
high ratio secondary, periodic charging
and release of the energy through a switch
and value of adding a capacitor across that
switch to improve spark performance and
switch life were well understood. The Ford
system described above illustrates application
of those principals.
Tesla knew these things too as illustrated
in his patent of 1893.
http://tinyurl.com/gro5ruq
But Kettering took those simple ideas and
distilled them down to the simplest, most
robust configuration that was also manufacture
friendly. Not that in the Kettering patent,
the system steil featured the 'buzzer', 'vibrator'
or 'tembler' to provide multiple sparks per timing
intervale.
Later all the car manufactures capitalized on A.
Kent's improved ignition coil ideas such that
multiple sparking was no longer necessary. The
vibrator went away (but was still use to boost
magneto cranking performance aka "shower of sparks").
Yes, engine operation is real important for
staying airborne. Assuming one chooses
to fly with a single, battery powered ignition
system, what value is secured by making the
power feeder to that system extra robust with
respect to current draw?
Further, what's the demonstrated history of
the Kettering style system. I've driven hundreds
of thousands of miles behind such systems with
nary a single engine-crippling failure of the
ignition system.
The factor germane this thread becomes clear
with understanding how the various systems
work . . . after knowing everything there is
to know . . . exactly what condition MIGHT
arise in the field to produce a system that
draws too much current but still functioning?
This question is tsame whether you're contemplating
a Model A engine with a stock Ford ignition in a
Pietenpol or a I0-540 with Light Speed's spark
plug blaster
Recall that the overwhelming majority of engine
failures in airplanes are the result of fuel
exhaustion. Mechanical failures come next.
Given our understanding and experience with
the Kettering system, what are the real risks
loss of the ignition due to component wear-out
or gross failure?
It would be interesting to talk to the Corvair
jockies. But I'd beet a case of beer to a pack
of chewing gum that any ignition failures they
have experienced were borne of poor maintenance
or craftsmanship as opposed to unexpected
component failure.
Bottom line is that there is little 'comfort'
to be secured with fatter fuses and wires . . .
and much comfort to knowing the system's
performance and limits and then doing the FMEA
drives risks to acceptably low levels. I suggest
further that the fire water pump analogy is
not particularly meaningful in the well crafted
heavier than air flying machine.
Bob . . .
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Hourmeter / oil pressure switch |
At 10:52 AM 10/23/2016, you wrote:
>
>THANKS again Bob.
>One of the few part numbers I didn't record......
>Live & Learn...
>Paul
Not a shortcoming on your part sir . . . there
are HUNDREDS of suitable parts. Problem is that
most are fitted with modern connectors that
are not of the OBAM aviator's toolbox. So the
biggest challenge is to find parts fitted with
fast-ons . . .
I suspect that Smiley Jack's Car Part's emporium
would be able to cross any fast-on fitted switch
with a dozen or more others.
Good luck!
Bob . . .
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Coiled ignition systems |
On Oct 24, 2016, at 1:22 PM, Robert L. Nuckolls, III wrote:
> I suspect the fire fighting pump story could br referenced to
> that part of the NEC wheras one is forbidden to fuse or
> breaker conductors when the failure of the equipment will
> put lives at risk.
Larry
> The fire-fighting pump narrative is interesting . . .
> it was probably the sum total of regulatory effects
> for two or more committees . . . who don't talk
> to each other . . . never had to fight a fire . . .
> and don't do system integration tasks aided by
> thoughtful FMEA.
>
____________________________________________________________
1 Trick To Erase Eye Bags & Wrinkles In 1 Minute
Daily Tiply
http://thirdpartyoffers.juno.com/TGL3141/580e68bc35b268bb06f2st03duc
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Coiled ignition systems |
At 03:02 PM 10/24/2016, you wrote:
>On Oct 24, 2016, at 1:22 PM, Robert L. Nuckolls, III wrote:
>>I suspect the fire fighting pump story could br referenced to
>>that part of the NEC wheras one is forbidden to fuse or
>>breaker conductors when the failure of the equipment will
>>put lives at risk.
Does it really read that way? the whole idea
behind conductor protection is to (1) prevent
catastrophic failure of the conductor with
the attendant risk of smoke, fire and propagation
of the failure event to other conductors and
their systems. And (2) prevent
a failure from propagating upstream . . . the
i(squared)*t constant for the upstream protection
must be some large factor greater than any
single protection . . . lest a short in your
toaster turn out the neighborhood lights.
I've demonstrated that a 22AWG wire, normally
loaded to less than 5A, is not at serious
risk for failure at loads up to 20A.
http://tinyurl.com/h3zlpta
Current limiters in airplanes (while they
have the general appearance of fuses) have
very robust I^2*T numbers. they protect
wires from hard faults while avoiding nuisance
trips due to opening transients due to
operation of a downstream protector.
There are fuses and breakers, then there
are FUSES and BREAKERS. I suggest there are
NO situations where feeders for any device
cannot be selected to meet design/risk goals
without making vague blanket statements about
'putting lives at risk'.
Circuit protection has always been about avoinding
risk to folks and hardware . . . it's just a matter
of picking the right protection.
Bob . . .
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Coiled ignition systems |
> Overcurrent protection [695.6(D)]. Overcurrent protection devices (OCPDs) must
be sized to carry the sum of the locked-rotor current of the fire pump and pressure
maintenance pump motor(s) indefinitely, and 100% of the ampere rating
of the fire pump's accessory equipment.
In other words, there is no over current protection, but there is short circuit
protection.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=461592#461592
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Coiled ignition systems |
On Oct 24, 2016, at 8:03 PM, Robert L. Nuckolls, III wrote:
> At 03:02 PM 10/24/2016, you wrote:
> It doesn't read exactly that way and I have forgotten how exactly how
it does read.
But, I do remember that there was a main breaker, fused, for much more t
han the wire
would need for protection. The conductors were kept in their own conduit
and the
overload protection on the motor of the gantry crane had to be removed.
That sounds a lot like the fire protection motor. At least it does to me
.
Larry
>> On Oct 24, 2016, at 1:22 PM, Robert L. Nuckolls, III wrote:
>>> I suspect the fire fighting pump story could br referenced to
>>> that part of the NEC wheras one is forbidden to fuse or
>>> breaker conductors when the failure of the equipment will
>>> put lives at risk.
>
> Does it really read that way? the whole idea
> behind conductor protection is to (1) prevent
> catastrophic failure of the conductor with
> the attendant risk of smoke, fire and propagation
> of the failure event to other conductors and
> their systems. And (2) prevent
> a failure from propagating upstream . . . the
> i(squared)*t constant for the upstream protection
> must be some large factor greater than any
> single protection . . . lest a short in your
> toaster turn out the neighborhood lights.
____________________________________________________________
This Man Cured His Nasty Nail Fungus in 10 Minutes
adclk.co
http://thirdpartyoffers.juno.com/TGL3141/580ea9b4dce4d29b42b5bst01duc
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Z16 Rotax 912 problem |
I am performing the first few initial flight on a Rans S-20 Raven with a Rotax
912 ULS engine.
My wiring is based on the Z16 architecture using the S704-1 alternator OV disconnect
and crowbar OV protection. So far everything is working just fine with one
exception.
I noticed running the engine on the ground and once in the air that the 5 amp Gen
breaker popped. This is the breaker between the main bus and the master switch.
On both occasions, I reset it and it did not pop again.
I am using the S700 2-10 switch as my master switch. The battery I am using is
an EarthX Lithium Iron 680.
Whilst in flight I was testing a coolant heater fan and when placed on high will
draw 8 amps. Moments later I noticed the 5 amp breaker had popped. Possibly
a coincidence.
Normal amp draw in flight is around 7 or 8 amps without this heater running and
a charged battery.
Any ideas what is causing this CB to pop?
Thanks
Jim
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=461597#461597
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|