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Flysimware avatar image
Flysimware asked N6722C edited

Electrical issues and questions

First I wanted to ask a question if there was a way to charge an emergency battery from other main batteries and then just isolate from the charging bus to prevent this emergency battery from getting charged by the alternators. If no way to do this in cfg I am aware i can use an Avar set code. I would ask if we can get something like this that would be great. Many aircraft have backup batteries.


For the max load ability for connections this is great but it pulls the breaker if you go over the limit. I think most times these are limiters and would prevent more than the max amps to pass. And there is not breaker to push back in as these are bus connections. You could code one but this project does not have such circuit breaker. So maybe you can clear this up if I am wrong but I think a limiter is better and to just fail any extra amps passing and not pull a breaker. I thought I would share this as i am not 100% clear myself if this is accurate on how a limiter works. But also maybe we can get both options or swap over in the future if this is more frequently used in the electrical systems.


There is also circuits known as TIES. These tie the left to right buses to keep a loop circuit but can be separated by pulling the tie breaker leaving each on a separate path. I tried to use a cross connection seen here and I find it sorta worked but causes issues for paths for other circuits where they had extra long paths that made no sense. So this is for sure not going to work for now. But a suggestion in case this can get implemented.


All these questions and ideas can be put on the back burner I am ok with what we have now and also not sure I would even want to use the ties as this would not be noticed by the user. But if you do have any answers or info on the charging battery to battery or limiters I am all ears. Thanks.

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Flysimware avatar image Flysimware commented ·

Update on the limiters.

PTM said this but this is If a limiter would fail...Now I wonder if the max amp entered after a connection is for the bus amp limit as you simulated or for a limiter as I have been explaining.

If both 275 A current limiters fail in flight (Note for different schematic)
B. The essential buses will remain powered by the generators 

This seems to be more like what you have simulated now. basically you set the max amps for that bus.

If an overload sensor shuts off power to a main bus, power may be restored by: 
A. Resetting the control CB after the overload sensor cools and resets 
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Flysimware avatar image Flysimware Flysimware commented ·

Maybe you can help on this issue. After more testing I found it odd that If I do add a 275A limiter connection BATTERY_CHG_BUS to GEN_BUS's and 50A connection for BATTERY_CHG_BUS to ESSENTIAL_BUS's they detect the starter circuit amps. Just because the buses are connected out side the path it seems to go through the limiter. But there is no current flowing through the limiters in the real aircraft only here in this simulation.

So to get around this I simply added STARTER_BUS's and this fixed the issue. But we should just point the circuits directly to the BATTERY_CHG_BUS. This is the only circuit I am aware of that actually comes directly off the BATTERY_CHG_BUS as the rest come from the main, essential or ac buses like most typical systems. So any info would be great.


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N6722C avatar image
N6722C answered N6722C edited

I have always considered a Limiter" as used in an aircraft electrical system, as "in effect", a self resetting, current thermal current trip.

ie sometimes called an "An auto-reset breaker"

If the current flowing through the limiter exceeds it set value, then after a delay, inversely proportional to how much higher that current is, the device Opens and stops the current flow -- but after a time, when it cools down, it self resets, and will either stay reset if the current is now below its trip value, or if not, and there is still excessive current, the delayed trip mechanism starts again.

As far as I know, there is no direct support for such a limiter in MSFS's electrical system, but it is easy enough to code whatever you need yourself, in a fully customized manner.

BTW. Also missing in the MSFS Electrical system, is the concept of an inline Diode, often used when combining (with isolation) two buses to form a combined bus.

(not so easy to code !! -- or is it ?? )

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