REFLECTOR:Looking for suggestions about fire detection

[Paul Calhoun]

Jim, 
Would not your eight thermal fuses work just as well attached to the
engine mounts forward of the engine and attached to the plenum and
engine bolts in the rear of the engine near the cowling exhaust? This
would avoid problems arising when the cowls are detached. The 22g wire
{perhaps 18g)would be suspended in space between attachment points. Each
fuse would possibly need to be anchored at both ends of the fuse.

Just thinking aloud.
Paul

-----Original Message-----
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org] On
Behalf Of Jim Agnew
Sent: Monday, May 19, 2003 7:32 AM
To: Velocity Reflector
Subject: Fwd: Re: REFLECTOR:Looking for suggestions about fire detection


Will have to post the picture on the Galery later, it is
too big.

Jim
--- Jim Agnew <jim_agnew_2@yahoo.com> wrote:
> Date: Mon, 19 May 2003 05:03:08 -0700 (PDT)
> From: Jim Agnew <jim_agnew_2@yahoo.com>
> Subject: Fwd: Re: REFLECTOR:Looking for suggestions about fire 
> detection
> To: Velocity Reflector <reflector@awpi.com>
> 
> Added a low res copy of the picture.
> 
> Jim
> 
> 
> Wayne,
> 
> This is exactly the circuit I used several years ago and
> it
> works well.  You need to keep the sensors in the 140
> degree
> C (284 F) range or a little lower since that is very hot
> for fiberglass.  I used 4 sensors on each cowl half 2
> front
> about 18" apart under the area behind the engine in case
> gas or oil ran back burning and two in the rear of the
> cowl
> just forward of the reinforcing ridge about 12" apart to
> get fire exiting the cowl.  The upper cowl has the
> sensors
> in the same place.  Obviously this should be looked upon
> as
> a "possible fire warning" circuit since a sensor or wire might fail.  
> I used #22 tefzel wire and covered all of the
> wire on the cowls with one fine bid leaving the sensor
> body
> exposed. 
> 
> Now for the real trick, I originally used locking plugs
> on
> each cowl to connect the wires.  I quickly found that
> this
> was a real pain and decided to make an automatic
> connector
> so I could just install the cowl haves without worrying
> about the connections.  I settled on alarm system window/sliding door 
> Foil Take-off Contact switches (example picture attached) that you 
> should be able to get inexpensively from alarm system installers.  
> They have high
> pressure wiping nickel contacts with one or more
> "fingers",
> depending on the make, and are very dependable.  Install
> the fixed portion on the engine bulkhead and the moving
> contact on the cowl.  It will take some trial and error
> in
> placement and mounting.  Mine are mounted on the side
> curve
> of the cowl. 
> 
> Hope this helps those planning to use this type of
> system.
> 
> Jim
> 
> 
> --- Wayne Owens <wamowens@bellsouth.net> wrote: Woops.
> What
> Digi-Key calls them now is Thermal Cutoffs. They list a
> bunch from Panasonic  for various temperatures in degrees Centigrade. 
> Part numbers are similar to P10925-ND.
> 
> 
> Flashing LEDs show up in a couple of places L20691-ND has
> a
> built in resistor for 13 volts 671499-ND requires a
> 1000 to 2000 ohm 1/4 watt resistor in series according to
> how bright you want it on the panel. Don't go much below 
> 1200 ohms. 
> 
> If the attachment is too large I will post it to the
> Jamaican goose thingy. Wayne
> 
> ----- Original Message ----- From: Ronnie Brown To: reflector@tvbf.org

> Sent: Sunday, May 18, 2003 8:53 AM
> Subject: Re: REFLECTOR:Looking for suggestions about fire detection
> 
> 
> Wayne.
> 
> How about a part number?  I did a search on Thermal at Digikey and got

> no response.
> 
> THANKS! Ronnie
> 
> ----- Original Message ----- From: Wayne Owens To: reflector@tvbf.org 
> Sent: Saturday, May 17, 2003 6:12 PM
> Subject: Re: REFLECTOR:Looking for suggestions about fire detection
> 
> 
> I used Thermal fuses (from Digi-Key) in a string
> (series) around likely hot spots. One end is grounded and
> the other end is tied to the anode of a flashing red LED 
> (also Digi-Key)on my annunciator panel. The LED anode is
> fed from a resistor tied to positive voltage (cathode is
> grounded) but the fuse string keeps the anode low until
> one
> of them blows (overheats). That allows current to flow
> through the flashing LED to ground. You should insert a
> normally closed "press to test" switch in the string
> also.
> Wayne ----- Original Message ----- From: PVTPIL8@aol.com
> To: reflector@tvbf.org Sent: Saturday, May 17, 2003 4:18
> PM
> Subject: REFLECTOR:Looking for suggestions about fire
> detection 
> 
> 
> I've got the fire suppression worked out now were looking
> for the early detection. Anyone have some suggestions.
> Wayne or Scott?? 
> 
> 
> 
> 
> 
> =====
> James F. Agnew Jim_Agnew_2@Yahoo.Com Tampa, FL Velocity
> 173
> Elite Aircraft Completed
> 
> 
> 
> =====
> James F. Agnew
> Jim_Agnew_2@Yahoo.Com
> Tampa, FL
> Velocity 173 Elite Aircraft Completed

> ATTACHMENT part 2 image/jpeg name=Takeoff Contact.jpg



=====
James F. Agnew
Jim_Agnew_2@Yahoo.Com
Tampa, FL
Velocity 173 Elite Aircraft Completed
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