Dave,
The unit is a combination of rectifier and regulator. The issues you
experience will depend on which component in which part of the circuit
fails.
There are (as far as I can identify - though I'm sure better qualified
contributors will correct me if I'm wrong) three modes of failure.
If you are really lucky, it will fail open-circuit, in which case
everything continues to work fine but your battery discharges. The
ammeter will show a discharge.
If you're not so lucky, the regulator fails and sends unregulated DC to
your battery. This will eventually boil dry, get very hot and may
distort and if no over-voltage protection is fitted, take out your avionics.
If you're really unlucky and the rectifier section fails, this can
squirt unrectified AC into the main bus and kill just about everything
except your ignition.
Which CB breaks depends entirely on how your aircraft was wired up and
it is these failure modes that have caused such spirited debate when
discussing "the right way" to wire up a panel.
Nigel
On 07/04/2014 18:13, david park wrote:
>
> Nigel,
> Would i be correct, in the event of regulator failure, i am going to see?
> 1.over/under voltage on volt meter ?
> 2.main cb break?
> 3.Ameter indication - discharge?
>
> Action - switch off alternator? And any unnecessary drain on battery.
> Dave Park
>
>
> Sent from my iPhone
>
>
>> On 7 Apr 2014, at 15:24, Nigel Graham <nigel_graham@m-tecque.co.uk> wrote:
>>
>>
>> This is an interesting discussion.
>> If the aircraft wiring has been well designed and installed and if the
>> correctly
rated breaker (or fuse) has been installed to protect the desired equipment,
then it is surely reasonable to suppose that the only time the breaker would
pop, or the fuse blow, is if something has failed. No amount of in-flight
fiddling is going to repair a shorted or broken wire, nor replace a failed
capacitor,
resistor or semiconductor (dare I mention Rotax/Ducati Regulator? .....
best not perhaps).
>> Re-setting a popped breaker without identifying why it popped is surely
>> asking
for trouble. Do you wait for the first signs of smoke before finally getting
the message?
>>
>> The only thing a pilot can do is recognise that a particular service has gone
down and, depending on flight criticality, divert or continue.
>> The only time to investigate the problem will be when you are safely down as
the cause will almost invariably be in an inaccessible place.
>>
>> Popped breakers are easy to spot, but fuses are not immediately obvious -
>> unless
you have chosen the ones that Rowland has used which incorporate a "failure"
LED.
>> This does of course require them to be mounted where you can see them
>> .......which
brings us back to the OP.
>>
>> Nigel
>>
>>
>>> On 07/04/2014 13:42, David Joyce wrote:
>>>
>>> Rowland, I don't dispute the electrical safety. It is just the distraction
of having to dig around to make a diagnosis and alter any circuitry rather than
having it plain obvious, right under your nose. I am strongly of the opinion
that anything that increases the workload/distraction factor in an emergency
is a thoroughly bad thing and leads to a lot of stall/spin deaths.
>>> Regards, David
>>>
>>>
>>> Rowland Carson <rowlandcarson@gmail.com> wrote:
>>>>
>>>>> On 7 Apr 2014, at 11:03, Brian Davies wrote:
>>>>>
>>>>> You make a very good point. The only electrical incident I have
>>>>> experienced
on my aircraft was a generator overvolt trip just after coasting out over
the Channel. After a careful check and a reset of the circuit breaker I was
able to proceed without any drama. The alternative, with a fuse not readily
accessible,
would have been a turn back to the airfield/refiling flight plan, revised
GAR arrival time etc. etc.
>>>>>
>>>>> The safety aspects are even more important..
>>>>
>>>>
>>>>> -----Original Message-----
>>>>> From: owner-europa-list-server@matronics.com
>>>>> [mailto:owner-europa-list-server@matronics.com] On Behalf Of David Joyce
>>>>> Sent: 07 April 2014 10:16
>>>>> To: europa-list@matronics.com
>>>>> Subject: Re: Europa-List: Parcel Shelf tray door access for fuses, CBS
>>>>>
>>>>> Tony & Rowland, I have a slightly different philosophical approach to
>>>>> this
question. A fuse may well go as part of some in air failure just possibly
accompanied
by fire or smoke. Time spent working out what is happening threatens
your safety. As with an engine failure serious distraction and stress can lead
to speed decay and a stall/spin accident. So I prefer my fusing system to be
out where it is immediately obvious what has blown and for this reason I
recommend
switchable circuit breakers, all labelled and readily visible. They have
the added benefit of readily allowing switching off of circuits to deal with
emergencies such as regulator failure. Regards, David Joyce, G-XSDJ
>>>> David, Brian - thanks for your comments. I've tried to do simple Failure
>>>> Mode
& Effects Analysis (FMEA) on both types of circuit protection remembering
that I'll be trying to fly the aeroplane at the same time. My planned "mission
profile" is such that a failure of any single electrical item should not
compromise
flight safety, and in this I agree with Bob Nucknolls, who has a lot more
experience than me in aircraft electrics. (With 32 years' professional
experience
in electronic research I feel I also know a bit about the "electrics" aspect
if not the "aircraft" aspect.) See the following postings:
>>>>
>>>> http://www.aeroelectric.com/articles/fuseorcb.html
>>>>
>>>> http://www.aeroelectric.com/articles/fusvsbkr.html
>>>>
>>>> http://www.aeroelectric.com/articles/fusvbkr2.html
>>>>
>>>> You'll see there are strong arguments (& feelings!) on both sides. I can
>>>> only
say in the light of my own knowledge that I took time over my choice and feel
comfortable with it.
>>>>
>>>> in friendship
>>>>
>>>> Rowland
>>>>
>>>> | Rowland Carson ... that's Rowland with a 'w' ...
>>>> | <rowlandcarson@gmail.com> http://www.rowlandcarson.org.uk
>>>> | Skype, Twitter: rowland_carson Facebook: Rowland Carson
>>>> | pictures: http://picasaweb.google.com/rowlandcarson
>>>>
>>>>
>>>>
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