---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 10/24/16: 7 ---------------------------------------------------------- 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 _____________________________________ Time: 10:24:47 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 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 _____________________________________ Time: 10:28:02 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 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 _____________________________________ Time: 01:03:25 PM PST US From: Larry Mac Donald Subject: Re: AeroElectric-List: 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 _____________________________________ Time: 05:04:41 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 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 _____________________________________ Time: 05:31:42 PM PST US Subject: AeroElectric-List: Re: Coiled ignition systems From: "user9253" > 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 _____________________________________ Time: 05:40:22 PM PST US From: Larry Mac Donald Subject: Re: AeroElectric-List: 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 _____________________________________ Time: 07:44:39 PM PST US Subject: AeroElectric-List: Z16 Rotax 912 problem From: "romaja" 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 ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.