Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2b5) with ESMTP id 141231 for flyrotary@lancaironline.net; Sat, 05 Jun 2004 23:55:33 -0400 Received: from EDWARD (clt25-78-058.carolina.rr.com [24.25.78.58]) by ms-smtp-01-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i563sSfP011431 for ; Sat, 5 Jun 2004 23:54:30 -0400 (EDT) Message-ID: <000801c44b79$fa3415e0$2402a8c0@EDWARD> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: LS1 Coils - amp draw? Date: Sat, 5 Jun 2004 23:54:33 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0005_01C44B58.72E6CC70" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0005_01C44B58.72E6CC70 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageYes, John, I have also read Bob's well thought out and reasoned = philosophy about fuses and circuit breakers. However, after over 2000 = hours of military flying there is no question that temporary conditions = have caused circuit breakers to pop and they have successfully reset. = Having had access to the military maintenance reports on such and with = all respect to Bob (who I do respect, indeed) there was never ONE case = where it was the circuit breaker malfunctioning. I disagree that there = is danger to the wiring by resetting a circuit breaker, if it is a = sustained overload (wire shorted to ground), the circuit breaker will = not stay engaged (even if you hold it in - I know I've tried) so the = wire will not melt. On the other hand, if it was a temporary situation = then a reset may well get you your equipment back. However, I do agree, that you certainly should go with the philosophy = you feel most comfortable with. That's certainly why I stay with = circuit breakers and others chose fuses. Hopefully a fuse will never = blow and a circuit breaker will never pop {:>) Ed Anderson RV-6A N494BW Rotary Powered Matthews, NC ----- Original Message -----=20 From: John Slade=20 To: Rotary motors in aircraft=20 Sent: Saturday, June 05, 2004 11:29 PM Subject: [FlyRotary] Re: LS1 Coils - amp draw? Ed said:=20 John, I don't know the current draw, but I would strongly suggest = that you replace fuses in critical circuits like ignition with quality = circuit breakers. Fuses are OK and have their place and I used them in = my aircraft but, in my opinion they do NOT belong in a critical = circuit. I have never reset a fuse, but I have reset circuit breakers = that popped due to a temporary overload and got the system back in = operation. FWIW=20 Ed, As always I appreciate you're input. As you probably know, this is an = age old discussion which has been played out ad nausium by people far = more qualified than I. Bob Nuckolls had a very comprehensive paper on = the subject on his web site http://aeroelectric.com=20 I think the logic goes something like this: 1. It is better to plan for a failure and be able to complete the = flight without the offending item, than it is to try to ensure that the = item never fails. It WILL fail sometime. Take a look at his product = "guarantee".=20 2. If a circuit breaker pops, either you have a bad breaker, or = there's a reason for the overload. Resetting it in the second case is a = bad thing, since you could now be overloading the wire. If it had been = a fuse, then you wouldn't have had to reset it in the first case. 3. If a fuse blows, or a breaker pops, then the right thing to do = (according to Bob) is to continue with you're backup plan and fix the = problem on the ground. In this case that meant run home on trailing = coils only. (not that I knew this at the time) Of course, many old and bold flyers have stories of saved bacon from = resetting breakers. We've all heard them, and I believe them. Bob would = [and does] argue that these incidents were mostly bad breaker incidents, = and there should have been a backup plan that didn't involve resetting = the breaker. Given this argument, a fuse is more reliable.=20 In my case, maybe the coils take 7 or 8 amps each. I'd designed the = circuit for one coil, forgetting that there was double the draw because = there were 2 coils on each circuit. So, perhaps I was in danger of = seriously overloading the wire. Had I reset a breaker maybe I'd have had = a fire to deal with instead of just a rough engine. Not a bad example of = Bob's point. Understand, I'm not so much arguing for one side or the other, as I am = making sure that both sides are presented. I chose to follow Bob's = logic. However - trying to cover my back (in case he was wrong) my fuses = are within reach during flight, and I have spares lined up on the back = of the fuse panel. :)=20 Regards, John ------=_NextPart_000_0005_01C44B58.72E6CC70 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Yes, John,  I have also read Bob's = well=20 thought out and reasoned philosophy about fuses and circuit = breakers. =20 However, after over 2000 hours of military flying there is no question = that=20 temporary conditions have caused circuit breakers to pop and they have=20 successfully reset. Having had access to the military maintenance = reports on=20 such and with all respect to Bob (who I do respect, indeed) there was = never ONE=20 case where it was the circuit breaker malfunctioning.   I = disagree=20 that there is danger to the wiring by resetting a circuit breaker, if it = is a=20 sustained overload (wire shorted to ground), the circuit breaker will = not stay=20 engaged (even if you hold it in - I know I've tried) so the wire will = not=20 melt.  On the other hand, if it was a temporary situation then a = reset may=20 well get you your equipment back.
 
However, I do agree, that you certainly = should go=20 with the philosophy you feel most comfortable with.  That's = certainly why I=20 stay with circuit breakers and others chose fuses.  Hopefully a = fuse will=20 never blow and a circuit breaker will never pop {:>)
 
 
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
From:=20 John=20 Slade
Sent: Saturday, June 05, 2004 = 11:29=20 PM
Subject: [FlyRotary] Re: LS1 = Coils - amp=20 draw?

Ed said: 
 John,  I don't know the = current=20 draw, but I would strongly suggest that you replace fuses in critical = circuits=20 like ignition with quality circuit breakers.  Fuses are OK and = have their=20 place and I used them in my aircraft but,  in my opinion they = do NOT=20 belong in a critical circuit.  I have never reset a fuse, but I = have=20 reset circuit breakers that popped due to a temporary overload and got = the=20 system back in operation.  FWIW 
 
Ed,
As always I appreciate = you're input.=20 As you probably know, this is an age old discussion which has been = played out=20 ad nausium by people far more qualified than I.  Bob Nuckolls had = a very=20 comprehensive paper on the subject on his web site http://aeroelectric.com=20
 
I think the = logic goes=20 something like this:
 
1. It is better to plan = for a=20 failure and be able to complete the flight without the offending item, = than it=20 is to try to ensure that the item never fails. It WILL fail sometime. = Take a=20 look at his product "guarantee".
 
2. If a circuit breaker = pops, either=20 you have a bad breaker, or there's a reason for the overload. = Resetting it in=20 the second case is a bad thing, since you could now be = overloading the=20 wire.  If it had been a fuse, then you wouldn't have had to reset = it in=20 the first case.
 
3. If a fuse blows, or a = breaker=20 pops, then the right thing to do (according to Bob) is to continue = with you're=20 backup plan and fix the problem on the ground. In this case that meant = run=20 home on trailing coils only. (not that I knew this at the=20 time)
 
Of course, many old and = bold flyers=20 have stories of saved bacon from resetting breakers. We've all = heard=20 them, and I believe them. Bob would [and does] argue that these = incidents=20 were mostly bad breaker incidents, and there should have been a backup = plan=20 that didn't involve resetting the breaker. Given this argument, a fuse = is more=20 reliable. 
 
In my case, maybe the = coils take 7=20 or 8 amps each. I'd designed the circuit for one coil, forgetting that = there=20 was double the draw because there were 2 coils on each circuit. So, = perhaps I=20 was in danger of seriously overloading the wire. Had I reset a breaker = maybe I'd have had a fire to deal with instead of just a = rough=20 engine. Not a bad example of Bob's = point.
 
Understand, I'm not so = much arguing=20 for one side or the other, as I am making sure that both sides are = presented.=20 I chose to follow Bob's logic. However - trying to cover my back (in = case he=20 was wrong) my fuses are within reach during flight, and I have = spares=20 lined up on the back of the fuse panel. :)=20
 
Regards,
John
 
 
 
 
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