X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 18 Apr 2006 12:26:44 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m25.mx.aol.com ([64.12.137.6] verified) by logan.com (CommuniGate Pro SMTP 5.0.9) with ESMTP id 1071691 for lml@lancaironline.net; Tue, 18 Apr 2006 01:27:31 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.6; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m25.mx.aol.com (mail_out_v38_r7.5.) id q.330.3015b4c (4402) for ; Tue, 18 Apr 2006 01:26:43 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: <330.3015b4c.3175d293@aol.com> X-Original-Date: Tue, 18 Apr 2006 01:26:43 EDT Subject: Re: [LML] request suggestions to stop fuel pump from running dry X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1145338003" X-Mailer: 9.0 Security Edition for Windows sub 5300 X-Spam-Flag: NO -------------------------------1145338003 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 4/17/2006 9:42:27 P.M. Central Standard Time, troneill@charter.net writes: To those who've been there-done that on early Lancairs -- request your comments. I want a minimum-management on-off fuel supply. For my L235 w/ IO320, I'm now running the fuel line from each wing tank through a filter on each Facet pump, then from each pump -- both into an open Tee, up to the header tank -- Control of the Facet wingtank pumps' is on-off with an optical level-sensor in the header, to break or complete the plus-circuit 12VDC to each/both tanks' power-on/off switches. Left and right tank Facet pumps individual switches are normally left on, and powered when a/c master is on. A red 'pumping' light is in the wing tank pumps' power circuit, cycles on and off as sensor demands fuel for the header. When light stays on, attention is called to the How can power to the L and R wing tank Facet pumps automatically switch off when the wing tanks are dry? From header, fuel flows through manual on-off valve, through filter to boost pump (recirculate pressure circuit) , to engine driven pump, through fine filter to fuel servo, to spider and injectors (airflow performance.) Would it hurt the Facets to run if one runs dry before the other? (No check valves; Flow is one-way through the pumps). Terrence, There is a device that senses the current draw change in Facet pumps when they start pumping air and then shuts off the pumps- See: _http://www.ppavionics.com/XFR.htm_ (http://www.ppavionics.com/XFR.htm) I do not use this device and have run the pumps "dry" from time to time with seemingly no problem. I had a similar desire for simplicity when I constructed my system some 15 years ago. I have an automatic system that keeps the header between 8 and 9 gallons (full) by pumping from both wings simultaneously. I know the wings are "dry" when the header drops to 7 gallons and the wing fuel levels indicate zero (zero indication when wing tanks are less than 2 gallons). The "dry" pump running condition only lasts for about 6 minutes at 10 gph. A float valve sensor indicates when the header has dropped to 8 gallons and a timer is automatically started. If 6 seconds passes before the float would reset the timer by going above 8 gallons, the pumps are started and are run until the float indicates full. The timer protects against falsely starting the pumps in turbulence for only a momentary run. Each pump (located in the wheel well) runs an independent line to the header. There are switches to run the automatic system or each pump individually. The VM EPI 800 system provides for very accurate fuel level monitoring in all three tanks with warning lights for lo fuel in each wing and the header and a lo total as measured by flow rate. The advantages of such a system are that there are at least 8 gallons in the header in case of a complete electrical failure, the wings are pumped out together thus the lateral trim remains throughout the flight unless someone jumps, there is no selector valve and the fuel in each wing is used completely since it can be pumped dry (less than 1 cup unusable) in level flight. Scott Krueger AKA Grayhawk Lancair N92EX IO320 CS Prop Slow Build 1989, Flown 1996 Aurora, IL (KARR) Eschew Obfuscation! -------------------------------1145338003 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 4/17/2006 9:42:27 P.M. Central Standard Time,=20 troneill@charter.net writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3D"MS Reference Sans Serif"=20 color=3D#000000 size=3D2>
To those who've been=20 there-done that on early Lancairs -- request your comments. I want a=20 minimum-management on-off fuel supply.
For my L235 w/ IO320,= I'm now=20 running the fuel line from each wing tank through a  filter = ;on=20 each Facet pump, then from each pump -- both into an open Tee, up to=20= the=20 header tank --
Control of the Facet=20= wingtank=20 pumps' is on-off with an optical level-sensor in the header,  =20
to break or comp= lete the=20 plus-circuit 12VDC to each/both tanks' power-on/off=20 switches. 
Left and right tank F= acet=20 pumps individual switches are normally left on, and powered when a/c maste= r is=20 on.   A red 'pumping' light is in the wing tank pumps' power=20 circuit, cycles on and off as sensor demands fuel for the header.&nbs= p;=20  When light stays on, attention is called to the
How can power to= the=20 L and R wing tank Facet pumps automatically switch off when= the=20 wing tanks are dry?   
 
From header, fuel=20 flows through manual on-off valve, through filter to boost pump=20 (recirculate pressure circuit) , to engine driven pump, through fine filte= r to=20 fuel servo, to spider and injectors (airflow performance.)
Would it hurt the Fac= ets to=20 run if one runs dry before the other? (No check valves; Flow is one-w= ay=20 through the pumps).
Terrence,
 
There is a device that senses the current draw change in Facet pumps wh= en=20 they start pumping air and then shuts off the pumps- See:
 
http://www.ppavionics.com/XFR.htm=
 
I do not use this device and have run the pumps "dry" from time to time= =20 with seemingly no problem.  I had a similar desire for simplicity = when=20 I constructed my system some 15 years ago.  I have an automatic system=20= that=20 keeps the header between 8 and 9 gallons (full) by pumping from both wings=20 simultaneously.  I know the wings are "dry" when the header drops to 7=20 gallons and the wing fuel levels indicate zero (zero indication when wing ta= nks=20 are less than 2 gallons).  The "dry" pump running condition only lasts=20= for=20 about 6 minutes at 10 gph.  A float valve sensor indicates when the hea= der=20 has dropped to 8 gallons and a timer is automatically started.  If 6=20 seconds passes before the float would reset the timer by going above 8 gallo= ns,=20 the pumps are started and are run until the float indicates full. The timer=20 protects against falsely starting the pumps in turbulence for only a momenta= ry=20 run.  Each pump (located in the wheel well) runs an independent li= ne=20 to the header.  There are switches to run the automatic system or each=20= pump=20 individually.  The VM EPI 800 system provides for very accurate fuel le= vel=20 monitoring in all three tanks with warning lights for lo fuel in each wing a= nd=20 the header and a lo total as measured by flow rate.
 
The advantages of such a system are that there are at least 8= =20 gallons in the header in case of a complete electrical failure, the wings ar= e=20 pumped out together thus the lateral trim remains throughout the flight unle= ss=20 someone jumps, there is no selector valve and the fuel in each wing is=20= used=20 completely since it can be pumped dry (less than 1 cup unusable) in lev= el=20 flight.=20
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 CS Prop
Slow Build 1989, Flown 1996=20
Aurora, IL (KARR)

Eschew=20 Obfuscation!
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