Excellent, thanks
Will
William Daniell
LONGPORT
+57 310 295 0744
On Fri, Apr 6, 2018, 12:50 Mike Gregory <m.j.gregory@talk21.com> wrote:
> Will,
>
>
> You could achieve the objective of shedding all non-essential loads by
> turning off the master and having an =9Cemergency bus=9D for
essential items.
> This does not need to be elaborate =93 it could simply be a 3-way c
hangeover
> switch for your second pump: BUS-OFF-BAT instead of the usual BUS-OFF.
>
>
> In your case, with a mechanical pump that would normally keep the engine
> going unless you happen to be on full boost at the time of alternator
> failure, this would allow you to shed everything then switch the pump to
> BAT if you need it.
>
>
> Good luck with your trip!
>
>
> Best wishes,
>
>
> *Mike*
>
>
> *From:* owner-europa-list-server@matronics.com [mailto:
> owner-europa-list-server@matronics.com] *On Behalf Of *William Daniell
> *Sent:* 06 April 2018 15:11
> *To:* europa-list@matronics.com
> *Subject:* Re: Europa-List: Rotax 914 Electric fuel pumps
>
>
> Mike
>
>
> Naturally I would never leave the pumps on after parking because I always
> use and follow my checklists :-). Actually mine are quite noisy Bosch
> injection pumps so its probably not likely.
>
>
> Thanks for your comments, much appreciated and valid points.
>
>
> My main aim is to simplify the electrical system precisely for safety
> sake. I have a secondary aim which is my flight to the US. There are so
me
> quite long legs over water or jungle (which amounts to the same thing).
I
> want to be able to maximize the electrical range by switching off all
> unnecessary electrical loads. For me this includes everything except wha
t
> is needed to run the engine range as my back up batteries and handheld
> devices will take care of the flying aspect.
>
>
> So ideally Id like to have one buss which I can switch off to achieve thi
s
> minimal electrical load. At the moment I think the only things which
> require separate switches are
>
> - Master
> - mags
> - Avionics 1 - ADSB XPNDR RADIO Intercom
> - Avionics 2 - AP servos in case they start acting strangely I
> would like to able to switch them off separately.
> - Fuel Pumps x 2 - sometimes on the ground one wants to fiddle with
> the EFIS without the pump draining the battery.
> - Landing and Anti Col lights
>
> Connecting a pump to the battery might be a moot point because sudden and
> complete alternators failures are very rare and also my Rotax 912 turbo h
as
> a mechanical pump which in theory should maintain up to 29 in at sea
> level. I have yet to test this.
>
>
> Will
>
>
> William Daniell
>
> LONGPORT
>
> +57 310 295 0744
>
>
> On Thu, Apr 5, 2018 at 7:32 PM, Mike Gregory <m.j.gregory@talk21.com>
> wrote:
>
> Hello Will,
>
>
> You could connect the second fuel pump direct to the battery, via a
> fuse/CB and switch as for the trim circuit, but why would you wish to?
>
>
> In the event of alternator failure, unless you have a low-capacity main
> battery, you have plenty of time to shed loads according to how long you
> need to keep airborne. In the event of a forced landing and turning off t
he
> main bus with the master switch, the electric trim is kept operational to
> avoid heavy stick forces, but this logic does not apply to the fuel pump.
>
>
> If the engine has stopped and you are making a forced landing, a single
> action to turn off the master switch before contact with the ground will
> kill all electrics (except the trim and your built-in standby batteries)
> and minimise the risk of a post-impact fire caused by an electrical short
> circuit and hefty current from the main battery. In particular, it will
> also stop the fuel pumps from potentially squirting fuel all over the
> wreckage, without your having to remember to switch off your fuel pump of
f
> separately.
>
>
> Of course, you would never shut down the engine after parking, turn off
> the master switch and forget to turn off your fuel pump!
>
>
> Best wishes,
>
>
> *Mike*
>
> Dr Mike Gregory
>
> Europa Club safety officer
>
> 01480 451655
>
> 07885 355765
>
>
> *From:* owner-europa-list-server@matronics.com [mailto:
> owner-europa-list-server@matronics.com] *On Behalf Of *William Daniell
> *Sent:* 05 April 2018 17:25
> *To:* europa-list@matronics.com
> *Subject:* Europa-List: Rotax 914 Electric fuel pumps
>
>
> I have the Europa System with one of the pumps connected direct to the
> alternator and the other to the bus.
>
>
> I get the logic of a direct connection to the alternator.
>
>
> Why isn't the other pump connected direct to the battery so that if the
> alternator fails you can switch off the buss run one pump off the battery
?
>
>
> (My EFIS has a back up battery and I carry a hand held so I can operate
> with the buss off.)
>
>
> thanks
>
>
> Will
>
>
> William Daniell
>
> LONGPORT
>
> +57 310 295 0744
>
>
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