> The last two or three times I have gone flying I have
> experienced a problem with the 5A ALT FIELD circuit
> breaker popping. The solution at first seemed easy just
> push it back in and all is well. It occurs usually at
> start up soon after I turn on the radio panel circuit.
>
> A couple of flights ago it popped a couple more times
> in the cruise and I reset it with no further problems.
>
> Yesterday however it popped quite a number of times (5
> or 6) and only settled down after I had turned the
> radio master off and back on again. I don't see how
> turning the radios off would affect the ALT circuit
> breaker except I suppose they use the most load.
>
> Looking at the circuit the breaker is located between
> output C on the voltage regulator and the main power
> bus (and thus the battery positive). Very simple.
>
> The only thing I can think of is that the voltage
> regulator is spiking at more than 5 amps until it
> 'warms up' or reaches some kind of battery charged
> point after the battery has been used after start
> (although the engine typically fires after just a few
> turns).
>
> Any ideas and/or solutions as to what the problem might
> be would be appreciated. I would like to trouble shoot
> before replacing the regulator but do not want to
> remove the panel unless I really have to.
Maybe I am being thick but no-one else has said anything.
On my 912S there is no ALT field circuit let alone a
breaker for the ALT field circuit. I have just the
standard Rotax alternator - not any add-on.
So my question is - in which circuit is your breaker ? If
it is in the main feed from the regulator back to your
plus buss then you need a 25A breaker not a 5 A breaker !
The Europa circuit diagram shows this as a 30A slow blow
fuse between the B terminal on the regulator and the buss.
The alternator has two (screened) wires going to it. They
go to the G terminals on the regulator and are AC. No
field cable.
Now I have read your email again and I see that you
answered my question. Your breaker needs to be 25A. The R
+B and C terminals on the regulator are all connected
together. That location is NOT an ALT field circuit !
So, in conclusion I don't think I am being thick !
Remember breakers do not trip the instant that the quoted
rating is exceeded. They normally are rated to trip in x
seconds at three times the load, and y seconds at twice
the load ... etc.
Richard
Europa tri-Gear G-OWWW High Cross
Willing to be shot down if someone knows differently (and
can argue their case !)
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