Hi Dave,
My alternator voltage normally shows
as 13.8 – 14.4 volts and has for years. Even with the battery off
line it reads a nominal 14 volts (don’t ask how I know {:>)). Right
after shut down my battery voltage will often read around 13 Volts – but will
generally decay to around 12.7-12.8 volts.
Not knowing what your nominal voltage is –
hard to say what the cause may be. By the way, my alternator is the stock
Mazda Rx-7 which has continued working well for over 10 years.
I would say to confirm you fancy talking
voltmeter’s findings first with a separate voltohmeter, before anything
else. I have a “Low Voltage” warning light that started
coming on after a number of years – turns out the circuit controlling it
had slowly drifted out of calibration over the years. An adjustment of a
Pot put it functional again.
My personal opinion is that I would
carefully monitor the voltage, but I would try a few local flights just to see
if the situation continued.
Let’s know what you find
Ed
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of David Leonard
Sent: Sunday, June 14, 2009 7:21
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?
--
David Leonard
Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net