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Loss of Electrical Power

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fredmoss

Member
Don't need to start a flame war here -- but, I've got conflicting advice on something and I know I can be put straight pretty quickly in here.

The two most common EI makers are Unison (LASAR) and Lightspeed (PLASMA).

I have heard that only the the LASAR has magneto backup incase of a total electrical failure. If this isn't the case (or if it is) how does the PLASMA handle loss of electrical power and keep the prop turning?

If anyone feels compelled -- I would really like to hear opinion, conjecture or silly, wild speculation on which system is superior for fuel economy/performance as well.

Thanks!
 
dual plasma = dual batteries. thought is chance of losing both batteries is pretty slim.

single plasma + mag = it'll keep running w/o batteries.
 
Devil's advocate here -- how long would the batteries last in that scenario? I fly my low-slow Cherokee 140 over some pretty inhospitable domain in Australia. Unlike the US with alternate airports ever 200feet there are many occasions when I'm hours from an alternate.

Also, if you use half mag / half EI -- doesn't that effect the performance and do you reap the full benefits of EI?

Just askin'
 
Devil's devil says that slow Cherokee's hours away from an alternate even in the US :)

Seriously -- you can guesstimate.. LSE publishes what their current draw is (something like 1.5A, IIRC)...

I'm sure George can/will throw some numbers at us. :)
 
To echo Radomir, I also understand that the low current draw of the Lightspeed will give you plenty o' time to get on the ground with the ignition system still functioning off batt power. However, I am running a mag on the right and a LS plasma2+ on the left. 150 TT and no issues.
 
I'm operating from memory here, but I believe that the Lightspeed Plasma system keeps functioning down to ~5.5V. The idea is to size your battery such that you always have more electrical capacity for your EI than you do fuel in your tanks.

I'm keeping one mag though, just so I'm not entirely dependant on a functioning electrical system.
 
I've had Both

Well, I had the Lasar in my RV-6 and I have a LightSPEED in my Rocket. In my mind, the Lasar is the worst of both worlds. It's a clunky magneto and it's expensive. The LightSPEED, or any other EI for that matter, will give your engine better or no worse performance than the Lasar without the expense and maintenace of a magneto. In my 30 years of flying, I've experienced numerous magneto problems, including problems with the Lasar units. My EI doesn't have any moving parts. Pretty hard to argue reliability with that. You do need to plan for either a magneto backup or dual battery to ensure power.

I will say that my experience with Lasar service was outstanding. They quickly swapped out my mags without question when I had problems. Great guys to deal with.
 
I flew home 4+ hours from Mexico with an offline alternator (broken B lead terminal), Slick mag + Lightspeed Plasma II. And that's with 2 stops/starts (had to clear customs!).

The Lightspeed ignition hardly consumes any current at all. I did shed load to ensure it wouldn't be an issue...but it didn't come anywhere near being an issue.
 
Look at P-Mag

Dual, independent batteries are needed for EI systems like Lightspeed. Have you ruled out P-mags?
 
how long would the batteries last in that scenario?
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Like Dan C., I have 1 mag, 1 LSE II, and I too have lost my alternator in flight, over mtns no less. Was a complete nonevent. I also shed some load just to be on the safeside.

doesn't that effect the performance and do you reap the full benefits of EI?
Click to expand...


I hear that all the time, but those of us flying with only 1 LSE have proven to ourselves that you most definitely do get benefits from only one. I love the setup and it has been completely problem free in 3 1/2 yrs.

Dual, independent batteries are needed for EI systems like Lightspeed.
Click to expand...

This needs clarification: Dual, independent batteries are needed for DUAL EI systems like Lightspeed.
 
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I run....

I run dual lightspeed with single battery but with the SD8 back up alternator.
 
I hadn't heard of the P-Mag before -- They should great. But.... how do they compare to the Lightspeed for performance?

Is it safe to say -- fuel burn / performance wise -- they are better than twin mags, but not as good as twin PLASMAs?

Like always, I'll listen to opinon as well as actual experience.

Thanks!
 
fredmoss said:
I hadn't heard of the P-Mag before -- They should great. But.... how do they compare to the Lightspeed for performance?

Is it safe to say -- fuel burn / performance wise -- they are better than twin mags, but not as good as twin PLASMAs?

Like always, I'll listen to opinon as well as actual experience.

Thanks!
Click to expand...
Fred,

They have not been without their teething problems. You can read about them here: http://www.vansairforce.com/community/showthread.php?t=16619

I do not know if they are better or worse than twin PLASMAs as I have only run Pmags on my O-290-D2. Other than an initial problem, which the guys at Emag Air seem to have fixed, all is good. Easy starts, smooth operation, good power, auto plugs (No more cleaning plugs. For the price, I'm just going to replace them.), vacuum advance, easy to time, etc., etc. That thread will give you more detail.
 
Can't recall if it is in the manual or if Klaus Savier told me over the phone, but expect 4% increase in power using single EI and 6% using dual EI. I use one LSE and one Slick mag, but now wish I had dual EI primarily from the maintenance point of view.

730 hours, never a problem with the mag and the only problem ever encountered with the LSE was a bad crimp that I made(the terminal looked like a motorcycle vs. train accident).
 
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