Jon Clements
Well Known Member
Last Wednesday I flew from Melbourne to Hobart in my RV-7 (about an hour of the 2.5hr flight is over water - Bass Strait). Faultless day, faultless flight. Yesterday I jumped in my RV and flew from Hobart to Bruny Island (short flight - no problems). When I departed Bruny Island I got a Low Voltage Warning on my EFIS a couple of minutes after take off. I have an EXP2 Buss DC Load Center with indicator panel and GRT EFIS. EXP2 Indicator panel showed that the Alternator had switched off and the GRT was showing 13.3Volts and dropping. I know you shouldn't turn the alternator off when the engine is running however I cycled the Alt Switch to see if i could get it to reset but no change resulted. At this point I was over water so I requested a direct track to Hobart and landed to check it out (while I still had some volts). By the time I landed I didn't have enough volts to start the engine. I recharged the battery overnight. This morning I started the engine and the Alternator came back on line and operated as normal. After warm ups I obtained a clearance and departed Hobart....3 mins later the Alternator failed again and I returned to Hobart. Before I shut down I momentarily switched the master switch off and then immediately back on - this recycled the alternator and it was operating normally again. I suspected it may have been an over voltage condition because the EXP2 Buss has over-volt protection which turns off the Alternator and you have to remove battery power to reset it. I did a ground run for approximately 3 minutes at 2200rpm but it continued to operate normally (i thought this might cause it to fail). I shut down and removed the cowls and checked the belt and checked the connectors. Removed and refitted the connector on the back of the Alternator - all seemed fine. Following this I replaced the cowls and then inspected the EXP2 Buss to see if there were any loose connections. All seemed OK. I started the engine again and Alternator was operating normally after run-ups and a higher rpm check. I taxied out to the runway and I watched the indicator panel on departure...shortly after take off (before I had reduced the rpm) the indicator panel showed a high voltage warning which then reverted to a low voltage warning probably due to over volt protection kicking in. I completed the circuit and landed, tied down my RV and came to the conclusion that I wasn't going to fly back over Bass Strait in a hurry so I jumped on a commercial flight home.
So now the dilemma - I didn't bring the Alternator home with me so I can't bench test it. My thoughts are to purchase a replacement alternator and take it to Hobart and fit it to see if the problem goes away. If not, then I will have a spare alternator and the problem is more likely to be a fault in the over volt protection on the EXP2 Buss.
Has anyone had a similar experience with the Vans 60amp Alternator and EXP2 Buss combination? If yes - what conclusions did you come to?
I have had a previous Internal Voltage Regulator failure with this same Alternator which was repaired. I believe the previous failure may have been caused by turning on the alternator switch after start up. Ever since that point I have been turning on the Alternator switch prior to start up and turning off after shutdown.
My Engine/Alternator has now done 193 hours.
Any help/thoughts would be appreciated because when I fly back to pick up my RV I want to be confident that I can get it home.
Also - does anyone know if the Plane Power 60 amp alternator is a direct swap (using same brackets and connector wiring/plugs)?
Thanks
Jon
So now the dilemma - I didn't bring the Alternator home with me so I can't bench test it. My thoughts are to purchase a replacement alternator and take it to Hobart and fit it to see if the problem goes away. If not, then I will have a spare alternator and the problem is more likely to be a fault in the over volt protection on the EXP2 Buss.
Has anyone had a similar experience with the Vans 60amp Alternator and EXP2 Buss combination? If yes - what conclusions did you come to?
I have had a previous Internal Voltage Regulator failure with this same Alternator which was repaired. I believe the previous failure may have been caused by turning on the alternator switch after start up. Ever since that point I have been turning on the Alternator switch prior to start up and turning off after shutdown.
My Engine/Alternator has now done 193 hours.
Any help/thoughts would be appreciated because when I fly back to pick up my RV I want to be confident that I can get it home.
Also - does anyone know if the Plane Power 60 amp alternator is a direct swap (using same brackets and connector wiring/plugs)?
Thanks
Jon
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