MGL ECB Switch Kit

Hey Gang,
I?m using 3 MGL ECB?s (electronic circuit breaker) plus 2 of the MGL switch kits on my RV project. Anyone else use these?
Here?s the problem. They sell you a little circuit board, switch, 3 lead LED, and the LED housing. When putting the LED housing over the LED, the outside LED leads short out on the LED housing and the LED housing is mounted on the Instrument panel which is connected to aircraft ground? I tried to put heat shrink tubing over the LED leads but now it?s too fat and the housing won?t go over the leads? I?m obviously missing something fundamental here?
Anyone else use this MGL switch kit and how did you deal with this issue?

Leds

Hi Ed. I got the MGL ECB but have not installed it yet. I'll be doing that this winter. I thought about making a custom PCB for holding the leds and switches.

You could also use a different led?

Looks like your in my hood. Are you based at pearson?

MGL Switch Kit

Yep, Pearson. Have an Aetolite 103 now.
Soon to have a RV6 their too.
Yuh at Learskn too?

MGL ECB is a nice unit.
Similar to Vertucal Power.

I?ve got 9 switches, each with a dual color LED.
Then, another 9 dual color LED?s showin the status of switches controlled by the EFIS. Looks nice but I don?t dare power up because of the short between the LED leads and LED housing.

Anyone else at all using the MGL switch Kit?

Insulate LED legs

I heard from MGL
They say -
?We tend to fit a single loose sleeve over the legs after bending the legs a bit to make some space.?

This makes total sense and I should have known. Guess I was thrown off by 3 things.
1. The manual is very complete with many pictures and no mention of insulating sleeve or bending the legs in slightly.
2. The kit contains every thing you need except the insulating sleeve. That?s ok, it just through me off.
3. Guess I just don?t know what i?m doing. I do now.

Moving on. It will be nice.

ECB Power feed wire protection

Do MGL ECB power feed wires coming from the switched side of the battery contactor to the input post of each ECB need protection?

I am concerned that that wire could see 500A in the event of a catastrophic failure and ovecurrent situation elsewhere downstream of the battery contactor. That would certainly fry the feed wire.

The solution would be to put a 60A CB in each feed wire - unless the ECBs have overcurrent protection built in, that I don?t know about. The reasons not to put them in include complexity, cost, weight, new failure points and longer check lists. However safety comes first.

I am at the detailed system design stage, though I have bought a full suite of MGL gear. So it is too late now to change horses and suggestions to abandon MGL for other alternatives wont be helpful I?m afraid. This question is about making it work safely.

So, do I need to protect that wire or not? What does the brains trust think?

In most certified (and homebuilt) a/c, the master contactor is considered to be 'pilot activated circuit protection'.

If you have convinced yourself that you need it, you can add catastrophic fault protection by installing a fusible link at the contactor end, soldered to the feed wire (it will only fail in..a catastrophe). Use 4" of wire that's 4 number sizes smaller than the feed wire. You do need to either use fuse link wire, or cover the link with a fire resistant sleeve.

Charlie

Fuses better I think

I am day VFR only, at least for the life of this panel.

Other than the ECBs, the items downstream of the battery contactor are the alternator and starter. The alternator will be okay because I am putting a 60A ANL on its B lead. The starter needs access to whatever the battery can give it so I just size the wires for that load. In any case, by definition, it remains out of action in flight.

So, I am flying along, the alternator throws a hissy fit, my ANL pops but everything else is okay and I am on battery power until I get to land. On another day, I am on the apron,starting my engine and my starter contactor gets stuck or the starter decides to produce smoke. I am not going flying that day.

However, nobody here is denying that my ECB leads could see full battery amps as the starter fails catastrophically. That means I have two very high power wires smoking and melting themselves to destruction INSIDE MY CABIN and very inaccessible under my tip-up sub-panel. That?s unless my no-longer-youthful reaction times get me to the master switch fast enough. I think I better protect those wires.

I can get automotive 60A ATC fuses that ?glow-when-blown? and I already have very nice modular panel-mounted blade fuse holders (from when I was planning an RV12 style fuse panel). This allows me to isolate the ECBs, if that would ever prove useful, and get the panel back in action more easily than replacing a fuse link after such a major event.

So that?s my decision. Thanks for the views expressed here. They really help

Loman,

Several assumptions there need attention.

The alternator itself (assuming it's 60A or less capacity) will never come close to stressing a 60A ANL, no matter how big a hissy fit it throws. The B lead should be sized to handle everything the alt can deliver (a few percentage points above rated output), so any protection device should be on the battery-facing end of the B lead; that's the source of danger to the B lead. (The ANL will not give any protection from an overvoltage event; you need OV protection for that.)

Starter current should flow from battery>master contactor>starter contactor>starter. Any downstream avionics, including any ECB module, should be fed from a 2nd wire on the load side of the master contactor, and would never see starter current in a properly wired system. (BTW, a 60A ANL is unlikely to survive starting current load.)

Do you have a copy of the Aeroelectric Connection book? If not, it would be a good idea to get a copy & study it before proceeding. (Can be downloaded for free)

Charlie

I can't point you to a readily accessible reference, but the 'machined pin' gold plated crimp style Dsub pins can handle around 7.5A each. The cheap, rolled pins can handle around 3A.

By using 'ballast wires' (3"-6" jumpers), you can parallel pins for added capacity. The ballast wires help the pins share the load equally.

Aeroelectric Connection is a great reference.

Charlie