cliffy Posted July 17, 2017 Report Posted July 17, 2017 Main 60 amp C/B popped and only battery was left. Shut down everything electrical and then the Master switch. Reset the breaker and turned on the Master and it popped again. All done trouble shooting in flight (old airline practice to reset only one time) Flew no electrical (like the old days) and landed. With the C/B connected to the Main Buss and then going from there to the alternator power post obviously something along the power lead to the buss or the Alt itself had a short to ground. Pulled the power lead from the post on the alternator and turned on the Master again- NO C/B pop this time. Confirmed the short is in the alt. These alternators have an Isolation Diode (2) in series with the power lead so that the battery can not feed the alternator after shut down. Big time dead battery then. My guess is that the Isolation diodes have shorted and battery power is going from the buss to the alternator as a dead short tripping the Main C/B. Luckily these alternators have an Isolation Diode mounting plate attached to the back of the alternator so removing it tomorrow to check the diodes will be fairly easy. Time will tell. Got lucky and found a complete InterAv system (as removed) with the same P/N for sale at a good price. Its on its way as a back up. Any Interav experts out there? I have found all the manuals for InterAv and Motorola on line. These are older Motorola alternators. Quote
neilpilot Posted July 17, 2017 Report Posted July 17, 2017 If you do install that other Interav, inspect the drive pulley to confirm it is correct for you engine. Alternators with the same PN can come with either a standard or wide deck pully. doubt you need it, but I have the Interav troubleshooting guide if you don't. Quote
orionflt Posted July 17, 2017 Report Posted July 17, 2017 put in the plane power replacement. Brian 1 Quote
cctsurf Posted July 17, 2017 Report Posted July 17, 2017 Had my InterAV alternator fail on me a while back (just after getting the plane) and I found a replacement as well. I seriously thought about the plane power replacement, but I really didn't want to rearrange my cowl when a direct replacement was so simple. I had my original rebuilt by an auto electric man (these alternators were also used on tractors) and have it as a backup, as good as new. Quote
cliffy Posted July 17, 2017 Author Report Posted July 17, 2017 Thanks, I have the InterAv guide and the full Motorola rebuild manual.. Looked at the Planepower unit as I was searching but found the good deal on the InterAV system. With my doghouse cooling changing to the Planepower would entail making all new seals for the front of the cowl so less work and $$$$ right now. I've had good luck with the InterAV for almost 17 years. This is the first failure I've had. Its just happening at 400 hrs since new. My biggest problem is that I'm so far out in the boonies, I have to ship everything out. Nothing local. Quote
cctsurf Posted July 17, 2017 Report Posted July 17, 2017 3 minutes ago, cliffy said: My biggest problem is that I'm so far out in the boonies, I have to ship everything out. Nothing local. At this point in history, I wonder what would be local for airplane parts. I think we all have to ship them. Just part of the deal. But then, I'm in the boonies too. Quote
cliffy Posted July 17, 2017 Author Report Posted July 17, 2017 Actually it was an oblique shot at local "non-aviation" "non-certified" repair shop for alternators. Can't get an 8130 from a local alternator shop. No offence meant to anyone, just a difference of opinion and one of my sticky points. Quote
cctsurf Posted July 17, 2017 Report Posted July 17, 2017 No, but the repair can be overseen by a repair station. I put more trust in someone who does these regularly than into an faa document any day. 2 Quote
Yetti Posted July 18, 2017 Report Posted July 18, 2017 Last repair station I had to deal with sent me a bunch of parts to put back together.... https://www.aspwholesale.com/alternator-parts/motorola.html Quote
LANCECASPER Posted July 18, 2017 Report Posted July 18, 2017 1 hour ago, Yetti said: Last repair station I had to deal with sent me a bunch of parts to put back together.... https://www.aspwholesale.com/alternator-parts/motorola.html It does not inspire confidence when they can't spell "alternator" Quote
Yetti Posted July 18, 2017 Report Posted July 18, 2017 Must be armatures at this Internet thing. 3 Quote
LANCECASPER Posted July 18, 2017 Report Posted July 18, 2017 1 hour ago, Yetti said: Must be armatures at this Internet thing. Haha good one Quote
cliffy Posted July 18, 2017 Author Report Posted July 18, 2017 But it can have a shocking outcome Quote
Yetti Posted July 19, 2017 Report Posted July 19, 2017 Too much resistance for me. Watt did you say is the matter with it? Quote
jamesm Posted July 19, 2017 Report Posted July 19, 2017 I am sorry was I impeding you ? in relative to power comment apparently the power could be changing with shifting phases with frequency . Really bad I know. Quote
milotron Posted July 19, 2017 Report Posted July 19, 2017 I have a phase reversal in my opinion on this. Is there a negative-like button? This is leaving me in-capacitorate, but my mind can be transformed! Sigh... Quote
LANCECASPER Posted July 19, 2017 Report Posted July 19, 2017 The comments are sure to Amp up now in a flash. Quote
Yetti Posted July 20, 2017 Report Posted July 20, 2017 Must be a phase y'all are going through. Could be a sine also. Quote
cliffy Posted July 20, 2017 Author Report Posted July 20, 2017 I was jolted awake by the thought of a shorted diode, maybe I can get the current to flow the proper direction when I get back from OSH Quote
Yetti Posted July 20, 2017 Report Posted July 20, 2017 I have no capacitance to continue this short conversation. Quote
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