Rage_kage Posted October 29, 2014 Report Share Posted October 29, 2014 I see a lot of twisted pair/shielded wires on heavy equipment. They are mostly for sensors and communication wires (cdl&j1939). I stumbled on some smarter people talking about there use in AC systems and transformers. Correct me if I'm wrong, a coil could be considered a transformer just in a smaller scale? So would there be any benefit to running a shielded twisted pair to the coil? Or am I just over thinking this. Quote Link to comment Share on other sites More sharing options...
03DMshee Posted October 29, 2014 Report Share Posted October 29, 2014 Your coil is fine...factory ignition systems are the best way to go on these bikes...some guys run aftermarket coils....buy most keep a stock ignition system Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted October 29, 2014 Report Share Posted October 29, 2014 Twisted sheilded is used a lot in newer installation of fir alarm , building communication/automation,some machinery. I build large projects in manhatten as an electrical foreman. All cabling your inquiring about is used for 24/48 v installallation and 4-20ma singnaling and sensors using resistance values . If you measured the voltage going to the coil on your shee with a fluke meter with peak voltage capability it would need to be rated for 600v I have yet to see a twisted sheilded rated for that use in 16awg Quote Link to comment Share on other sites More sharing options...
Rage_kage Posted October 29, 2014 Author Report Share Posted October 29, 2014 600v coming off the stator to the posts on the coil? Quote Link to comment Share on other sites More sharing options...
Atomic Monkey Posted October 29, 2014 Report Share Posted October 29, 2014 No benefit. Twisted pair is almost exclusive to the communications and IT industries. The shielding in the wire you're talking about is to prevent or reduce EMI. Ignition coils don't care about EMI, they produce it... which is the reason for resistor plugs. Now if your pickup wires were bundled with your spark plug wires. There would be a potential for EMI to produce false triggers, and that would require the pickup wires to be shielded to prevent misfire. That's about the only scenerio, aside from adding electronics, that would require shielded wire on a Banshee. Quote Link to comment Share on other sites More sharing options...
Rage_kage Posted October 29, 2014 Author Report Share Posted October 29, 2014 No benefit. Twisted pair is almost exclusive to the communications and IT industries. The shielding in the wire you're talking about is to prevent or reduce EMI. Ignition coils don't care about EMI, they produce it... which is the reason for resistor plugs. Now if your pickup wires were bundled with your spark plug wires. There would be a potential for EMI to produce false triggers, and that would require the pickup wires to be shielded to prevent misfire. That's about the only scenerio, aside from adding electronics, that would require shielded wire on a Banshee. ^ that's what I was looking for, thanks for clearing that up for me Quote Link to comment Share on other sites More sharing options...
Rage_kage Posted October 29, 2014 Author Report Share Posted October 29, 2014 Would a aluminum core wire make any difference in a small system like that? Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted October 30, 2014 Report Share Posted October 30, 2014 You're going to hurt yourself trying to over think a simple design. Quote Link to comment Share on other sites More sharing options...
Rage_kage Posted October 30, 2014 Author Report Share Posted October 30, 2014 You should see me at work. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted October 30, 2014 Report Share Posted October 30, 2014 That's not a good thing. And I hope people aren't compensating you for those habbits. Quote Link to comment Share on other sites More sharing options...
sheerider1026 Posted October 30, 2014 Report Share Posted October 30, 2014 Cdi. Capacitive discharge ignition. It gets voltage from the stator, steps it up, uses capacitors to store energy, then sends this amplified voltage to the coil, then is stepped up even more. If I had to guess, 20,000 volts at the plug? Quote Link to comment Share on other sites More sharing options...
Buckwheat Posted October 31, 2014 Report Share Posted October 31, 2014 Upwards of 50,000 volts in some cases. Especially in marine applications. Quote Link to comment Share on other sites More sharing options...
Rage_kage Posted November 1, 2014 Author Report Share Posted November 1, 2014 That's not a good thing. And I hope people aren't compensating you for those habbits.Your right having a ocd for repairs is stupid. Just make the customer pay for the same repair again. I clearly stated I'm not a electrical engineer, just a guy asking a question. Quote Link to comment Share on other sites More sharing options...
blowit Posted November 7, 2014 Report Share Posted November 7, 2014 I will offer some tech for the learning as I appreciate people that ask "why". Twisted pair wire is a way to keep all wires from following each other parallel the whole length of the wire. There are concerns for both inductance and EMI (electromagnetic interference). These types are wires are typically used exclusively for communications signaling with high carrier frequencies or digital data but similar tricks are used for heavy power applications like VFD motor drives where very high carrier frequencies are used and EMI can be an issue. Shielding is mostly to keep EMI out AND in. If you have signal wires touching VFD power wires, you can have issues. Shielding should block any cross communications. The shields are usually earth grounded to hold the shield at zero potential all the time. The "ignition coil" in the Banshee is indeed just another name for an isolation transformer. It is all about the number of turns over the core to determine the specific transformer step ratio. IIRC, the Banshee will see about 70VAC peak-peak from the CDI to the transformer and approx 7000V out. That would be an approx step ratio of 100:1 but I cannot remember exact numbers here. Now the resistors in plugs and caps is totally different and is targeting "back EMF" (electromagnetic field). Basically as a spark plug discharges, it has a tendency to send a return or reverse spike of energy back at the source. This spike in some instances can be higher than the operating voltage and can them be sent back through the transformer and back to the CDI. To snub this, a resistor is used in series. It is not recommended to use BOTH a resistor plug and cap!!! The Banshee uses a resistor cap so using a BR8ES plug (R=resistor) is not recommended. This will only further reduce spark energy. As a little TMI, VFD motor drives can have some nasty back EMF due to the carrier and operating frequencies. Basically EMF can build up bouncing between the driven motor and the motor drive IGBTs until the voltage of that EMF either destroys the insulation in the coil wire in the motor, or the IGBTs. This is why cable length/type are watched carefully and snubbers are common for long run applications. In short, the frequency of the CDI output to the transformer is of no concern operating at a feasible frequency limit of about 400hz. No biggy! The best thing you can do is provide properly sized wire so as not to lose any power through resistive losses. 16-18ga wire is actually plenty sufficient for this thus the factory wiring is just fine! Brandon Mull Engineering Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted November 8, 2014 Report Share Posted November 8, 2014 ^ mind blown and enlightened. Thanks Brandon. Always informative . Quote Link to comment Share on other sites More sharing options...
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