Current limiter and shunt firewall layout

[Mark L]

I am doing my electrical planning and installing some of my firewall components. I have a main 60-amp alternator and a sd-20 standby alternator. I plan on using a AFS engine monitor. Given this I plan on using a current limiter for each alternator and the required shunt for the AFS engine monitor on the main alternator wiring. Im trying to lay out these components (current limiters and shunt) on the firewall and install them before hanging the engine. Wondering if anyone else has done this an can shoot me an image to help me with the layout.

It appears this may vary a bit from Dynon and AFS components.

 

[axlr8r]

Me too

I'm also at this point, and I'm wondering if I can use the following:

1. "B" lead connected to shunt (on firwall) - Shunt connected to Current Limiter (on firewall) - "B" lead continues from CL to Master Contactor.

2. My friend suggests an alternative: "B" lead to CL to Shunt to Master Contactor.

I prefer #1 because it protects the Shunt too. Is there a problem with either one of these options.
Thanks
Steve

 

[RVG8tor]

Just did mine

I ended up deviating from the Aero Electric Connection drawings a bit and here is why. In my set up maybe yours the SD20 is a back up to the main alternator so only one should be operating at a time. You can put in two shunts and have two ammeters so you can see what each alternator puts out but only one should be making power at any given time.

My deal is Dynon 180 only supports one ammeter, now I could attach the two shunts to a switching system and I could toggle between the two shunts. I wanted to simplify things so this is what I did.

ANL protects main alternator B lead, Standby will be protected with a fusible link and attachs to the down stream side of the main ANL, this way if the main ANL blows, Standby can pick up the load. The shunt is down stream of them all so I will read on my single ammeter the power going to the main bus and battery from whatever is providing the power. I am also not using the hall effect sensor with the SD20, I have a load shed plan that I know will keep me at about 10 amps which should work. Note that the SD20 is only 20 amps at cruise RPM when you reduce power your load may start to lean on the battery.

I ran this by Bob Nuckoles and he said it would work, don't think he thought it was something he would publish though.

 

[axlr8r]

I like it

Thanks for your comments and the picture Mike. Just what I needed. Somehow, seeing the picture made it a lot easier to understand than my mental image.

 

[Mark L]

Another related question. Is there a preferred sequence of installation between the ANL current limiter and shunt? For example, alternator-current limiter-shunt-contactor OR alternator-shunt-current limiter-contactor or does it matter.