Mailing List flyrotary@lancaironline.net Message #46422
From: Al Gietzen <ALVentures@cox.net>
Subject: RE: [FlyRotary] Over Voltage?
Date: Sun, 14 Jun 2009 17:20:34 -0800
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

Dave;

 

What was your voltage reading a month ago?

Voltage regulators due vary a bit from one to another.  I probably have the same alternator (Mitsubishi- 70), and for the first 130 hours or so it ran in the range yours is now reading (according to the EM2).  Then it began to slowly increase to where it was cycling over 15.5.  That’s when I decided to replace the regulator.  There’s a re-build shop in Oceanside where I bought the regulator for $38.  Now it runs 14 – 14.5.  I think the actual is about 1/2v lower as the EM2 reads that much higher then my voltmeter.

 

I modified the alternator so I could provide external field with a ‘crow-bar’ over voltage protection. I don’t think it trips until about 18v. 

 

What battery do you use?  I found that my Odysee didn’t seem unhappy charging at 15. The higher charging voltage is mostly harder on the battery.

 

Al

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of David Leonard
Sent: Sunday, June 14, 2009 3:21 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Over Voltage?

 

Today retuning from my flight my voltmeter started to complain "check voltage".  The bus voltage was reading between 14.2 - 14.6 volts.  Right after shut down the battery voltage was reading 13.3 volts.

 

Is this a sign of impending over voltage failure of the regulator? 

I am using the stock 70 amp alternator.  Do I need to replace it right away?  Use an external regulator?  Is it safe to watch it for another flight or two and see what it does?  Is it possible that oil mist could have gummed things up a little and spraying some contact cleaner into the alternator might do the trick?

 

How much voltage is too much before I need to land right away?

Thanks all.


--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net

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