Grounding LSE ignition system

[N8RV]

The LSE ignition module has two shielded wires for power and ground. The problem is, the instructions say that the ground wire MUST be attached directly to the battery negative treminal and NOT grounded to the frame to avoid electronic noise. They're long, but not long enough to reach my rear-mounted battery.

Questions:

1) Has everybody really grounded to the battery and not to the frame?

2) If anyone has attempted grounding to the frame, was there indeed interference?

3) Can shielded wire be spliced effectively, or do I have to return the entire plug assembly to LSE and have them make one with a longer ground?

Thanks.

[81T]

If you have two wires it is an older system and is connected to the neg. term. on the batt.
The newer (after2005) use only one wire to the batt. and it's shielding is the ground return.

Hope that helps
Bruce

[grover]

shielded wire can be spliced just fine if needed with the little raychem solder shrink thingies.

[gmcjetpilot]

Originally Posted by N8RV

The LSE ignition module has two shielded wires for power and ground. The problem is, the instructions say that the ground wire MUST be attached directly to the battery negative terminal and NOT grounded to the frame to avoid electronic noise. They're long, but not long enough to reach my rear-mounted battery.

Questions:

1) Has everybody really grounded to the battery and not to the frame?
2) If anyone has attempted grounding to the frame, was there indeed interference?
3) Can shielded wire be spliced effectively, or do I have to return the entire plug assembly to LSE and have them make one with a longer ground?

Thanks.

I have talked to Klaus before. Not surprisingly people do not always follow this recommendation.

The reason for it, besides noise, for the direct battery connections, POS and NEG, I was told is reliability. There's nothing like a DIRECT connection to the battery. He's trying to avoid going through many conncetions, a master relay and a bus. Wire to battery period, is simple and reliable.

Ground wise, ground is ground. If you read Aeroelectic he has a central ground buss scheme, verse the shotgun grounding approach with random airframe grounds everywhere.

I am sure you are running a big fat POS cable fwd to the front of the plane, right? What are you doing about battery GND? Are you grounding locally in the back of the plane only? If you are, why not run an additional gnd wire, call it a ground strap, fwd. It does not have to be POS wire size but say #8 (or #6). 20 feet will add 1 lb. Probably a wash if you don't have to run the shilded wire aft.

You will still have the big GND cable from the battery NEG to the air frame ground, but this will be another ground wire, but smaller. Run that extra ground to a gnd block up front to the FW. The ground block can be grounded to the airframe locally as well as by the ground wire from the rear mounted battery. So it will be redundant. I doubt it will make noise. Some fear the ground loop. There is a thread on this right now. Personally ground loops are death for audio equip but not your LSE power line.

This ground block could be used to ground other items as well, or only the LSE if you are worried there will be noise.

I think Klaus is most worried about a 100% super reliable simple direct connection to the source of power, the battery. He want the least number of connections and parts between the EI BOX and power.

Now the power side is harder, since you are trying to avoid any device (master relay) between you and your LSE power supply, aka direct battery connection. I assume you are connecting your battery POS cable to a starter solenoid up front on the FW? You can pick the LSE power off that pos battery cable at the solenoid. However this is against Klaus's KISS principle, but many people do it. How many times does a master relay fail after its engaged? George.

[Mike S]

Wow George, you must have gotten those toes working pretty well-------I didnt see even one typo

Good to see you back.

[gasman]

Originally Posted by gmcjetpilot

I have talked to Klaus before. Not surprisingly people do not always follow this recommendation.

Now the power side is harder, since you are trying to avoid any device (master relay) between you and your LSE power supply, aka direct battery connection. I assume you are connecting your battery POS cable to a starter solenoid up front on the FW? You can pick the LSE power off that pos battery cable at the solenoid. However this is against Klaus's KISS principle, but many people do it. How many times does a master relay fail after its engaged? George.

I think Klaus wants the LSE to be treated like a MAG.... HOT ANYTIME THE (MAG/LSE) SWITCHES ARE ON. And also, to keeep working if you need to turn off the master switch during flight for any reason.

[N8RV]

Thanks for the replies, everyone. I've also been advised that the way it's wired now -- power from a battery buss instead of directly from the battery -- is just fine.

Not sure what to do. I'll probably just go ahead and run the wire back to the battery. Length is not an issue anymore, since it needs to go to a CB and a toggle switch anyway. Duh.

[gmcjetpilot]

Originally Posted by gasman

I think Klaus wants the LSE to be treated like a MAG.... HOT ANYTIME THE (MAG/LSE) SWITCHES ARE ON. And also, to keep working if you need to turn off the master switch during flight for any reason.

I did not look at it that way, you are right makes sense. Follow the instructions, daaa. Cheers

[Ted RV8]

Quote by gmcjetpilot

I have talked to Klaus before. Not surprisingly people do not always follow this recommendation.

The reason for it, besides noise, for the direct battery connections, POS and NEG, I was told is reliability. There's nothing like a DIRECT connection to the battery. He's trying to avoid going through many conncetions, a master relay and a bus. Wire to battery period, is simple and reliable.

Sorry, I couldn't resist. Usually we all have at least one or two typos. My spell check doesn't work when posting through VAF and I'm not savy enough with a computer to make it work.

As to the Lightspeed from my discussions with Klaus I think George is spot on.
Least chance of problems being wired direct.

Ted

[bhester]

Mine is powered from my Batt Buss and works great! Grounded on my forest of tabs common ground.