SD-8 question

db8 · #1 02-19-2009, 10:23 PM

Am wondering if most people with a SD-8 use a Hall Effect sensor or a shunt as described in Z-13? I wonder if one could use the main alternator Hall Effect for this because they won't both be on at the same time, or should I say powering things at the same time? Thanks. Dave

rwayne · #2 02-20-2009, 07:02 AM

My plan is to use a shunt for the main alternator and use the Hall Effect on the E buss power wire from the battery buss. My thought is that I will be able to see how much load I am drawing from both the battery and SD-8 since the SD-8 will max at 8 amps. I will use the AFS 4500 engine monitor.

N787TR · #3 02-20-2009, 07:55 AM

I'm using a AF-3500 which can read two amperages but one has to be a hall and the other a shunt. Given where the wires are running, I found it was easier to go with the standard shunt for the primary alternator on the lower right side of my firewall and keep the hall effect inside the airplane between the regulator and battery (they recommend that the regulator for the SD-8 stay on the cool side of the firewall).

-Todd

RV10Pilot · #4 02-20-2009, 02:42 PM

You can run the leads from both alternators through one hall effect sensor. Make sure the electrical flow is in the same directions for both wires. The sensor will read the total current flow through both wires.

Larry Rosen
RV-10 #356

db8 · #5 02-20-2009, 10:49 PM

Thanks Larry. I guess I could have been a little clearer on the original question, but you answered it. I don't see why I can't use the same hall sensor either (running both the SD-8 and primary through it). The only time I will be running the SD-8 with the switch "on" is when the main alt is not working for whatever reason (according to the voltage regulator...overvoltage, undervoltage, etc). So, that is what I will do unless I hear anybody else say this won't work. I sure wish the guy who left B & C was still there. He would know the answer right away. Dave

kentb · #6 02-23-2009, 09:09 AM

And it work fine.

Kent