X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 21 Dec 2009 08:36:37 -0500 Message-ID: X-Original-Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.122] verified) by logan.com (CommuniGate Pro SMTP 5.3c4) with ESMTP id 4033532 for lml@lancaironline.net; Mon, 21 Dec 2009 08:31:19 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.122; envelope-from=super_chipmunk@roadrunner.com X-Original-Return-Path: X-Authority-Analysis: v=1.0 c=1 a=Ax3k0XQfaZnnGoDz__cA:9 a=ry9ZATl5tIGaPfktqt__q-U1so0A:4 a=Nc9alglvwwNXAjM_:21 a=aO5Y688mTVljoHY0:21 a=SSmOFEACAAAA:8 a=Y2VNeNrzAAAA:8 a=yMhMjlubAAAA:8 a=TW66zc2HAAAA:8 a=HQ31llbKAAAA:8 a=KFGjw6lpRJs0MA8ms6wA:9 a=5H3DvVnqGI9428ToipMA:7 a=dUGloW5Svy7KzLoeCF4Z0ySq7BgA:4 a=fiX6q9z6Qyc2Y0XU:21 a=RSxplOLGHZN41jkM:21 X-Cloudmark-Score: 0 X-Originating-IP: 74.75.176.139 Received: from [74.75.176.139] ([74.75.176.139:58951] helo=Laptop) by cdptpa-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id F5/09-04641-5887F2B4; Mon, 21 Dec 2009 13:30:46 +0000 X-Original-Message-ID: <9D790D0B72314515A184509A3D0D5A70@Laptop> From: "Bill Wade" X-Original-To: "Lancair Mailing List" References: In-Reply-To: Subject: Re: [LML] Re: Firewall X-Original-Date: Mon, 21 Dec 2009 08:30:49 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_057C_01CA8217.E69825F0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18005 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18005 This is a multi-part message in MIME format. ------=_NextPart_000_057C_01CA8217.E69825F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I agree- finding a suitable temperature range in a specific location = would be difficult with the engine changing temperatures constantly as = loading varied and cooling airflow changed. The outlet would show any = increase no matter what the source. I'm thinking about point sources like exhaust joints or turbochargers = affecting nearby hoses. There are temperature indicating tapes that = could be placed to determine what the normal temperatures might be. It = might be possible to choose a fuse that would blow when the hose first = became exposed rather than allowing failure to create an alarm at the = outlet. -Bill Bill, I considered your approach when building my Lancair IV-P, and elected = to go with two temperature sensors instead. Rationale was that I didn't = know how to "calibrate" the thermal fuses without testing that was = beyond my capability.and probably interest. Basically I decided to = install temperature sensors near each cowling air exit rather than = guess at what value to use for the thermal fuses. I hooked the = temperature sensors to my MVP-50 engine monitoring system and recorded = the actual temperatures seen by the two probes during initial test = flying. After determining that the temps never went above 150F during = flight or ground operation, I set the alarm "trigger" temp for 170F. My = normal temperatures run between 120-135F in flight, meaning I will get a = warning if the cowl exit temperature increased by 35-50 degrees from = "normal." This is an arbitrary setting that has precluded any false = alarm to date.but then again I've not yet had a real alarm either. I = could probably generate an earlier warning by lowering the alarm temp, = and may do so the next time I fiddle with the MVP-50 alarm settings. Of = course, the objective is to generate an alarm for any "real" event, but = to not generate false alarms. This took quite a bit of fiddling with = most of the settings, but I am now very comfortable with what I have.and = love the system.=20 =20 Considering the consequences, I think a fire/overheat monitoring = system in the engine compartment is a very good idea, no matter what = system you use! =20 Bob =20 PS: The actual temperatures will be dependent on the sensor/fuse = mounting location.so don't use my figures; it's easy to determine your = own. ------=_NextPart_000_057C_01CA8217.E69825F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
  I agree- finding a suitable = temperature=20 range in a specific location would be difficult with the engine changing = temperatures constantly as loading varied and cooling airflow changed. = The=20 outlet would show any increase no matter what the = source.
 
  I'm thinking about point = sources like=20 exhaust joints or turbochargers affecting nearby hoses. There are = temperature=20 indicating tapes that could be placed to determine what the normal = temperatures=20 might be. It might be possible to choose a fuse that would blow when the = hose=20 first became exposed rather than allowing failure to create an alarm at = the=20 outlet.  -Bill
Bill,


I=20 considered your approach when building my Lancair IV-P, and elected to = go with=20 two temperature sensors instead. Rationale was that I didn=92t know = how to=20 =93calibrate=94 the thermal fuses without testing that was beyond my=20 capability=85and probably interest. Basically I decided to install = temperature=20 sensors near each  cowling air exit rather than guess at what = value to=20 use for the thermal fuses. I hooked the temperature sensors to my = MVP-50=20 engine monitoring system and recorded the actual temperatures seen by = the two=20 probes during initial test flying. After determining that the temps = never went=20 above 150F during flight or ground operation, I set the alarm = =93trigger=94 temp=20 for 170F. My normal temperatures run between 120-135F in flight, = meaning I=20 will get a warning if the cowl exit temperature increased by 35-50 = degrees=20 from =93normal.=94  This is an arbitrary setting that has = precluded any false=20 alarm to date=85but then again I=92ve not yet had a real alarm either. = I could=20 probably generate an earlier warning by lowering the alarm temp, and = may do so=20 the next time I fiddle with the MVP-50 alarm settings. Of course, the=20 objective is to generate an alarm for any =93real=94 event, but to not = generate=20 false alarms. This took quite a bit of fiddling with most of the = settings, but=20 I am now very comfortable with what I have=85and love the system.=20

 

Considering=20 the consequences, I think a fire/overheat monitoring system in the = engine=20 compartment is a very good idea, no matter what system you=20 use!

 

Bob

 

PS:=20 The actual temperatures will be dependent on the sensor/fuse mounting=20 location=85so don=92t use my figures; it=92s easy to determine your=20 own=85

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