Brad Posted December 19, 2014 Report Share Posted December 19, 2014 I got this message a couple of weeks ago and noticed that the amps went to about -51. I started shutting off electronics (no circuit breakers had popped) and unplugged a USB charger I had in the 12V outlet. Nothing cleared the condition immediately, but within about a minute or two, the amps returned to normal. All other engine indictions were normal. I haven't experienced this in the 10 or so hours since. Has anyone else experienced this or know what the cause may have been? It seems to me the drawing those amps through a circuit breaker would have tripped the breaker, so any issue must be upstream of that. Link to comment Share on other sites More sharing options...
Anticept Posted December 19, 2014 Report Share Posted December 19, 2014 -51 amps means you have a ammeter on the battery lead, not the alternator lead (the former is very typical of modern aircraft). The battery was discharging at an extremely high rate. Check for a charred or shorted wire (especially after the ammeter and before the breaker, if they are wired in this order), and test the battery breaker to make sure it pops correctly. After that, chalk it up to either your ammeter (the sensor), loose wiring, or the instrument is having problems. I don't know what type of ammeter you are using. There could be other things as well depending on the type. Link to comment Share on other sites More sharing options...
Brad Posted December 20, 2014 Author Report Share Posted December 20, 2014 Thank you Anticept. I'll do the visual and breaker check. I have delved into the electronics on the CTLS yet, so it will be a good exercise to start tracing circuits! Link to comment Share on other sites More sharing options...
Runtoeat Posted December 20, 2014 Report Share Posted December 20, 2014 jbm3, I'm not a wire wizzard as a few others are on this forum but I'm thinking this is a faulty gage or faulty indication of current. Seems there's very few wires (other than the cable from solenoid to starter) in our CT's that could handle that much current for even a few seconds without providing a couple of burnt ends of wire and some telltale smoke and smell and a some inoperative equipment. Link to comment Share on other sites More sharing options...
Anticept Posted December 20, 2014 Report Share Posted December 20, 2014 jbm3, I'm not a wire wizzard as a few others are on this forum but I'm thinking this is a faulty gage or faulty indication of current. Seems there's very few wires (other than the cable from solenoid to starter) in our CT's that could handle that much current for even a few seconds without providing a couple of burnt ends of wire and some telltale smoke and smell and a some inoperative equipment. That is most likely the case, but due to the extremely hazardous nature of shorts, a check of the breaker and, if it checks good, the wiring on the battery side should be looked at just in case. Electrical shorts are one of the most common causes of in flight fires. Link to comment Share on other sites More sharing options...
chanik Posted December 20, 2014 Report Share Posted December 20, 2014 If the voltage did not collapse to 9V or so while showing 51Amps then it has to be a flaky gauge Link to comment Share on other sites More sharing options...
Brad Posted December 20, 2014 Author Report Share Posted December 20, 2014 Thank you Kurt. Voltage was the first thing I checked and it was fine, that's why the reading didn't make sense. Still I'll do the visual to confirm nothing else seems out of line. Link to comment Share on other sites More sharing options...
Anticept Posted December 21, 2014 Report Share Posted December 21, 2014 Curt, Could you please comment on recommended capacitors for us. I just had mine replaced and I seemed to recall that there are better alternatives (larger capacity) than the original equipment. I am interested in the EE angle on this. He PMed me this capacitor model. I've installed it and it has rectified a number of very old and longstanding issues with noise in the electrical system. I'm in the process of putting together a packet for FD Germany's review to convince them that a larger capacitor, per rotax's recommendations, should be installed standard. It's BIG. You'll need to use adel clamps to hold it to the firewall, and do some electrical work to route the wiring and new ring terminal connectors to it. Be sure to cover up the ends so nothing shorts it either! Link to comment Share on other sites More sharing options...
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