Message-ID: <001d01c04f07$a9a804a0$e397a4d8@oemcomputer>
From: "Bill & Sue" <harrelson@erols.com>
To: <lancair.list@olsusa.com>
Cc: <Theo_Green@firstar.com>
References: <20001115054018.AAA20653@ns1.olsusa.com>
Subject: LNC2 automatic fuel system
Date: Wed, 15 Nov 2000 08:26:27 -0500
Reply-To: lancair.list@olsusa.com
Mime-Version: 1.0

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> I want to research the feasibility of a facet pump continually feeding the
> header and controlled with some sort of automatic switch. Any good plans
out
> there?

Good morning Theo,

In my 320 header tank I built in two float switches (Spruce). These allowed
me to design a simple system using relays to automatically fill my header
tank. The lower switch is activated when the fuel level reaches about 7
gallons. This activates one or both transfer pumps which stay on until the
upper switch (full) is made. My fuel system controls consist of the
following:
    1. Two DPDT switches, one for the right one for the left, each labled
Auto-Off-Manual. The manual position turns the respective pump on ignoring
any signals from the automatic system.
    2. One small push button labled "auto fill" which I can push to "fool"
the system into thinking that the lower fuel switch has been made. This
allows me to make sure that the header is full for take-off or approach.
    3. Two small red lights labled "auto fail" and "wing tank low". The auto
fail system looks at the automatic system and will light up if the low level
switch is made and there is no power going to at least one transfer pump OR
if the full switch is made and there IS power going to either transfer pump.
The "wing tank low" light looks at float switches built into the wing tanks
and will warn me if I'm trying to pump fuel from an empty wing.
    4. A cross flow valve. This simple addition allows for the failure of
one transfer pump. Either pump can pump fuel from both wing tanks.
    5. A sight gauge.
    6. A Vision Micro fuel quanty gauge with a low level warning.

The automatic circuit can be built from Radio Shack parts for 20 bucks.
E-mail me directly and I'll mail you the schematic if you want.

Bill Harrelson
harrelson@erols.com


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