I was getting a lot of variance in my voltage and amps. I changed the regulator out with a much more robust unit with a far better wiring harness set up. Also replaced a 5 year old battery. 

Upon a ground test I was seeing better voltage in the 12.5 to 13.1 range but still not the expected 14v. And the amps were still jumping around and often showing a negative 4 to 14 which is so odd.

When we built the plane 9 years ago we put in a B&C over voltage unit. I have always felt that was a mistake and causing problems. Ray from UL advised that an over voltage unit is not needed with our engines. So I removed it from the plane. Once I got it out it was clear there were problems. The power lead from the mini bus to the unit was melted and dark brown as was the bottom of the relay. Also looks like the diode in the relay is bad.

Now I am seeing a steady 13.9 to 14.1 volts at all rpms and a steady plus 8 to 16 amps depending on load and rpm. Yay, finally!

My question is what kind of readings are you folks seeing from your 350iS for voltage and amps at various rpm's.

Thanks in advance.

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My 350i, with upgraded regulator, puts out a steady 14.1 volts. Amps are another story. Amp reading wanders up and down and back and forth from 12 to 21 and at times higher. No clue as to why. I have over 650 hours on the engine so I quit concerning myself with it and just changed the alarm settings on my Dynon to not turn red until amps go over 22-24 range.



Thanks for the info. 

Hey Dave,

On my 20th test flight (right near the end of Phase 1) my original ULPower 350iS R/R gave up the ghost in flight. No issues returning to my home airport, but I was wary as to why. I found an R/R - related thread on this site and followed David J. Beaulieu's advice to purchase a Mosfet R/R from roadstercycle.com. (http://www.zenith.aero/forum/topics/regulator-rectifier-replacement) My original ULPower R/R readings varied from 13.2 - 14.7 volts depending on electrical load and throttle setting.  The new R/R, with over 100 hours on it, varies only about 1 volt either side of 14.3 volts regardless of flight conditions.  Some flights I never see it change at all.  It's a huge difference.

Thanks for that. I also saw a marked improvement after installing the Mosfet type regulator. 

I have the 350is (30 amp Stator) and am running it through an upgraded Mosfet R/R.  My volts are consistently in the low 14's and my amps are fairly consistent between high teens and low 20's.  I have a dual screen Dynon HDX system with AP.  I also have Aeroleds and under wing LED landing lights.

Thanks for that. Basically what I'm seeing now after the regulator change with a very similar panel set up as yours. 

Was getting a consistent 14.8, 14.9 volts with the stock RR. Swapped it out with a Mosfet noted earlier. Getting 14.3, 14.4 with the new one but also has a much better harness. I had changed out the original 12awg with 10awg wires on the original RR but really didn’t have much confidence in the setup.

With one pump running, strobes on, an iPod in a panel dock and a single Dynon HDX it shows 16-17 amps draw. Jumps to 24, 25 amps with both pumps running.


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