X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from omr-m02.mx.aol.com ([64.12.143.76] verified) by logan.com (CommuniGate Pro SMTP 6.0.4) with ESMTP id 6229389 for lml@lancaironline.net; Sat, 27 Apr 2013 10:20:33 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.143.76; envelope-from=Sky2high@aol.com Received: from mtaomg-da02.r1000.mx.aol.com (mtaomg-da02.r1000.mx.aol.com [172.29.51.138]) by omr-m02.mx.aol.com (Outbound Mail Relay) with ESMTP id D9CB17000008D for ; Sat, 27 Apr 2013 10:19:58 -0400 (EDT) Received: from core-mta002c.r1000.mail.aol.com (core-mta002.r1000.mail.aol.com [172.29.234.133]) by mtaomg-da02.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id A20F0E000088 for ; Sat, 27 Apr 2013 10:19:58 -0400 (EDT) From: Sky2high@aol.com Full-name: Sky2high Message-ID: <10c8f5.56f30a6f.3ead388d@aol.com> Date: Sat, 27 Apr 2013 10:19:57 -0400 (EDT) Subject: Re: [LML] Re: Prop overspeed??? MVP 50 indications To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_10c8f5.56f30a6f.3ead388d_boundary" X-Mailer: AOL 9.6 sub 168 X-Originating-IP: [67.175.156.123] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1367072398; bh=AEoGd82QUS/sLjWmxlGkzeFtzEY0QyJaK7KWpSy9W/M=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=t113vJW5v+ZvaKgTXA2YWrwlLP/2PyDV9L8d5VaoaIbC+ciN4gA2wG3Hc41wfyxI6 MCBplGYTF8G5VUW2aoXT7OJ9p1hsTqs8vD1MG1xtC2QH2yKNnN8uXGIuNq5+P8Fjup ilySqt4KrGRJ4+EeuLgQun9Dcam5IoY9ILE5VjWQ= X-AOL-SCOLL-SCORE: 0:2:458035232:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d338a517bde8e3167 --part1_10c8f5.56f30a6f.3ead388d_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Colyn, Yes, the backup battery is only for one ignition and the sole main battery is 28 AH. The voltage will drop to about 7 VDC (knocks out stuff that needs 9-32 VDC). "Why?" You might ask. 1. Battery is behind co-pilot seat. Cable run is about 7 feet to starter motor. 2. Cable is #4, not #2 in order to reduce weight. At hi amp draw even a small resistance in the cable/system leads to big voltage drops. 3. Engine has a CR of 9:1, thus a bit harder to turn. 4. Mstr Sw lights up certain things - Master relay, RMI Microencoder, S-Tec turn coordinator, gear locked lights and EPI 800 engine monitor. 5. B&C starter that does not draw more power as voltage drops unlike Sky Tec. This is good. 6. Heavy prop and damper is a lot of weight to get going although usual start commences by 1/2 to 1 revolution. Scott In a message dated 4/27/2013 8:21:35 A.M. Central Daylight Time, colyncase@earthlink.net writes: Scott, Did you get voltage drop on when starting off the main battery? I usually start on the main battery with the crossfeed off while my engine monitor is running (through diodes ) from both batteries. I wouldn't expect the voltage at the engine monitor to drop lower than the backup battery, even while cranking. I have the ability to use both batteries to crank but if I'm going to do that I manually shut off all avionics, one at a time. Colyn On Apr 27, 2013, at 7:03 AM, _Sky2high@aol.com_ (mailto:Sky2high@aol.com) wrote: Fred, Yep. Usually the Essential Bus is isolated from the Main Bus by a diode. I used one as described at http://periheliondesign.com/powerschottkydiodes.htm with a very low voltage drop (.2 to .3 VDC), other diodes may have drops of .5 to .7 VDC or greater. I also saw a hefty voltage drop when engaging the starter - enough so that the engine monitor ceased operating and then rebooted itself after engne start. The monitor was hooked up through the Essential Bus.. Scott In a message dated 4/26/2013 8:15:33 P.M. Central Daylight Time, _frederickmoreno@bigpond.com_ (mailto:frederickmoreno@bigpond.com) writes: Interesting MVP 50 indications. Occasionally in recent flights I get an alarm that oil pressure is high after start up, reads 100+ psi. Do a run up and it clears even before oil temperature changes. It comes and goes, and seems independent of RPM on the ground, so I put it down to instrument error instead of a stuck oil pressure relief valve. Possibly important note: My MVP 50 is on the essential buss along with my PFD, back up horizon and a few other things, which means the buss is hot when I turn on the master and do the start. So the voltage sag at the start may cause the MVP 50 to lose its brains momentarily. I have lots of voltage spike protections built into that buss, but not much one can do about voltage sags. Fred -------Original Message------- From: _Sky2high@aol.com_ (mailto:Sky2high@aol.com) Date: 27/04/2013 4:02:26 AM To: _lml@lancaironline.net_ (mailto:lml@lancaironline.net) Subject: Re: [LML] Re: Prop overspeed??? Angier, Your prop did not over speed. Note that while the pump was running the voltage was lower than during the time the pump was not running. While 13.2 VDC is not that low, the MVP may be sensitive to that or to an unusual ground loop relative to the pump ground. The same may be true for the fuel flow sensor. Check it out. I like the hydraulic pressure included in the data logging. Scott PS do not worry about 2710 rpm.. You may want to change the limit values slightly. Then again, why did the mstr wrn go away or did you reset it. In a message dated 4/26/2013 2:10:57 P.M. Central Daylight Time, _N4ZQ@VERIZON.NET_ (mailto:N4ZQ@VERIZON.NET) writes: Today's 2hr flight was normal in all respects with the single exception that immediately after liftoff, the MVP-50 began screaming 'check RPM'. The RPM display was close to 4000 and fuel flow spiked. Nevertheless engine sounds remained normal. Sure got my attention. At 6:29:28 and just as the gear started to come up is when the RPM indication spiked for all of about 5 seconds. Haven't seen this before. What would the common, everyday prop overspeed sound like?? not that I ever want to hear it.... Angier Ames N4ZQ <426131.jpg> -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html --part1_10c8f5.56f30a6f.3ead388d_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Colyn,
 
Yes, the backup battery is only for one ignition and the sole main bat= tery=20 is 28 AH.  The voltage will drop to about 7 VDC (knocks out stuff that= =20 needs 9-32 VDC).  "Why?" You might ask.
1. Battery is behind co-pilot seat.  Cable run is about 7 fe= et to=20 starter motor.
2. Cable is #4, not #2 in order to reduce weight.  At hi amp draw= even=20 a small resistance in the cable/system leads to big voltage drops.
3. Engine has a CR of 9:1, thus a bit harder to turn.
4. Mstr Sw lights up certain things - Master relay, RMI Microencoder, = S-Tec=20 turn coordinator, gear locked lights and EPI 800 engine monitor.<= /DIV>
5. B&C starter that does not draw more power as voltage drops unli= ke=20 Sky Tec.   This is good.
6. Heavy prop and damper is a lot of weight to get going although usua= l=20 start commences by 1/2 to 1 revolution. 
 
Scott
 
In a message dated 4/27/2013 8:21:35 A.M. Central Daylight Time,=20 colyncase@earthlink.net writes:
= Scott,=20

Did you get voltage drop on when starting off the main battery?
I usually start on the main battery with the crossfeed off while my= =20 engine monitor is running (through diodes ) from both batteries.
I wouldn't expect the voltage at the engine monitor to drop lower th= an=20 the backup battery, even while cranking.
I have the ability to use both batteries to crank but if I'm going t= o do=20 that I manually shut off all avionics, one at a time.

Colyn

On Apr 27, 2013, at 7:03 AM, Sky2high@aol.com wrote:
Fred,
 
Yep. Usually the Essential Bus is isolated from the Main Bus by a=20 diode.  I used one as described at http://perih= eliondesign.com/powerschottkydiodes.htm 
with a very low voltage drop (.2 to .3 VDC), other diodes may have d= rops=20 of .5 to .7 VDC or greater.  I also saw a hefty voltage drop when=20 engaging the starter - enough so that the engine monitor ceased operating= and=20 then rebooted itself after engne start.  The monitor was h= ooked=20 up through the Essential Bus..
 
Scott
 
In a message dated 4/26/2013 8:15:33 P.M. Central Daylight Time, frederickmoreno@bigpond.com=20 writes:
--
For=20 archives and unsub http://mail= .lancaironline.net:81/lists/lml/List.html

--part1_10c8f5.56f30a6f.3ead388d_boundary--
Interesting MVP 50 indications. 
 
Occasionally in recent flights I get an alarm that oil press= ure=20 is high after start up, reads 100+ psi.  Do a run up and it= =20 clears even before oil temperature changes.  It comes and go= es,=20 and seems independent of RPM on the ground, so I put it down to= =20 instrument error instead of a stuck oil pressure relief valve.&nb= sp;=20
 
Possibly important note: My MVP 50 is on the essential buss = along=20 with my PFD, back up horizon and a few other things, which means = the=20 buss is hot when I turn on the master and do the start.  So = the=20 voltage sag at the start may cause the MVP 50 to lose its brains= =20 momentarily.   I have lots of voltage spike protections= =20 built into that buss, but not much one can do about voltage=20 sags.
 
Fred
 
 
 
 
-------Original Message-------
 
From: Sky2high@aol.com
Date: 27/0= 4/2013=20 4:02:26 AM
To: lml@lancaironline.net
Subject: R= e: [LML]=20 Re: Prop overspeed???
 
Angier,
 
Your prop did not over speed.  Note that while the pump= was=20 running the voltage was lower than during the time the pump was n= ot=20 running.  While 13.2 VDC is not that low, the MVP may be=20 sensitive to that or to an unusual ground loop relative to the pu= mp=20 ground.  The same may be true for the fuel fl= ow=20 sensor.  Check it out.
 
I like the hydraulic pressure included in the data logging.<= /DIV>
 
Scott
 
PS do not worry about 2710 rpm..  You may want to chang= e the=20 limit values slightly.  Then again, why did the mstr wrn go = away=20 or did you reset it.
 
In a message dated 4/26/2013 2:10:57 P.M. Central Daylight T= ime,=20 N4ZQ@VERIZON.NET writes:
Today's 2hr flight was normal in all respects with t= he=20 single exception that immediately after liftoff, the MVP-50 began= =20 screaming 'check RPM'. The RPM display was close to 4000 and fuel= flow=20 spiked.
Nevertheless engine sounds remained normal. Sure got m= y=20 attention.
At 6:29:28 and just as the gear started to come up = is=20 when the RPM indication spiked for all of about
5 seconds. Hav= en't=20 seen this before.

What would the common, everyday prop=20 overspeed sound like?? not that I ever want to hear=20 it....

Angier=20 Ames
N4ZQ



<426131.jpg>




--
For=20 archives and unsub htt= p://mail.lancaironline.net:81/lists/lml/List.html