Amp readings???

[Paul 5r4]

Getting prepared for the first flight of N729PG... perhaps today!... but I have an amp meter question. I have the dynon d 120 and it's indicating anywhere from a -3 to +3 amps. On the first engine start a few weeks ago it was reading about +30 amps, then a couple days ago it was reading +17 amps and today I have the 3 and 3 situation. I have the 60 amp alt with the placement of the shunt to indicate -60 to +60. What are "normal" readings for the amp meter. I would expect an increase with a dead battery etc. but my battery is good. Hope I can get a resolution today so I'll feel good about a first flight. Thanks in advance.

 

[ChrisMallory]

I'm assuming you used the setup for Position A in the Dynon Manual. This will give you +/- 60 Amps going into or out of the battery. When you first start, you should get a larger spike as the battery recharges, then it will settle back down to the +/- 3 type number you are seeing. I think this is the way Cessna hooks up their ammeters.

Position B gives you the current flow from the alternaor to the battery and aircraft load. This setup will show the same initial spike as the battery recharges after start, then will settle to a lower number depending on how much equipment you have on. As you turn electics on, the meter will show more amps. I believe this is how Piper set theirs up.

It really depends what you want to see from your indicator. Position A is more of an ammeter while Position B is more of a load meter.

Bottom line is that in position A, your readings are normal. You would have to worry if it went larger negative, or stayed negative. That would mean the battery is draining.

Hope this helps.