C

crabandy

Well Known Member
Fuses are supposed to protect the wiring, but he install manual says:

"The shunt should be installed in-line with the current being sensed. As noted below, the appropriate wire should be cut and attached to each of the large 1⁄4? lugs. A one amp fuse or other form of circuit protection must be installed between the shunt and the applicable GEA 24/GSU 73 inputs to prevent inadvertent damage to the GEA 24/GSU 73"

In this instance is the 1 amp fuse protecting the device?
Perhaps the 24 awg fuseable link on the 22 awg wire would allow more than 1 amp to go to the device?
Sorry probably a little paranoid but I'm getting close to hooking up the batt for the first time and I'm hoping for no smoke.
 
Also, is it easiest to hook the main buss voltage wire to the main buss?

What are the discreet inputs for?
 
My mentor/friend said the G3X can be configured to read voltage from the power wire that is connected to the AHRS. So the volts 1 or 2 wire doesn't have to be hooked up unless you want to monitor other buss voltages.

Discreet inputs are used for any NO or NC switch like canopy closed etc.

I think...
 
No expert here but my belief is that the fuse or fuse link protection is so that if you get a short in the system or wire it will fuse and terminate the voltage very close to the source. Yes 26 or 24 ga. Will flow much more than 1amp but it is the weak link in the circuit. I originally allowed my system to read voltage from the already connected source but I was getting a low reading. This is because I have that source connected to the ess. Bus which is after the diode. I have now connected both volts 1&2 so that I can display both at the same time.
The discrete s are for many different alerts. I have one connected to my TCW backup battery and another connected to the GTN650 which has some alerts. As per the manual there are many things that can be connected. You can even invent uses. It simply goes to ground to proved the alert. ie canopy micro switch.
 
I think the issue is that the current shunt is typically installed in high current paths (that have large wire). When you attach your sensing wires you risk potentially putting a large amount of current down these wires if you were to get one of these wires shorted to the frame or ground. A fuse or similar device located near the shunt (the closer the better) will protect for this fault condition.
 
Fusing on Shunt Signal Wires

Hello Andy,

I haven't had a chance to investigate why this guidance was worded this way in the installation manual, but I am presently in agreement with the others who posted here.

The 1 amp inline fuses on these signal wires going from the shunt terminals to the GEA/GSU inputs is purely to protect these wires from overheating should they become chafed and shorted.

Thanks,
Steve
 
Thanks Mark!! Sounds like we have similar electrical architecture like Nuckolls's Z-13/8. You saved me work later on! I will use the power wire voltage to monitor ebuss volts and run main volts 1 to the main buss which operatess without diodes.
 
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