Return-Path: <13brv3@bellsouth.net> Received: from [205.152.59.67] (HELO imf19aec.bellsouth.net) by logan.com (CommuniGate Pro SMTP 4.1b9) with ESMTP id 2472920 for flyrotary@lancaironline.net; Sat, 12 Jul 2003 12:01:11 -0400 Received: from rad ([68.212.2.57]) by imf19aec.bellsouth.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20030712160039.VIOC2988.imf19aec.bellsouth.net@rad> for ; Sat, 12 Jul 2003 12:00:39 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: We have ignition Date: Sat, 12 Jul 2003 11:00:43 -0500 Message-ID: <007001c3488e$bfead520$0201a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0071_01C34864.D714CD20" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0071_01C34864.D714CD20 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable You could look at Bob Nuckolls's wiring diagrams at aeroelectric.com and talk to him on the aeroelectric maillist. I have his automotice = alternator overvolt "crowbar" protection circuit installed. Basically, you put the alternator field through a contactor which is activated by a switch, and deactivated by a 5a breaker if overvolts are sensed. John Slade =20 Thanks John. I'm familiar with electric Bob's info. I had his crowbar device on my RV-8, which had an externally regulated alternator. I considered installing his internal regulator version on the RV-3, but = just couldn't justify the effort. I have absolutely NEVER heard of a modern alternator causing damage from overvoltage, so I figure the risk is = minimal. Worst case, the EM-2 tells me I'm overvoltage, and I shut off the = master. That will allow the overvoltage to continue on the non-essential side of = the buss, but I can turn off the radio and transponder to save them. There really isn't anything else of significance to worry about. I'm still considering my options, but at the very least, I'll get rid of the = current switch for the excitation current. No good can be done with that = switch. Of course, since it's there already, I could use it to power a dedicated alternator contactor. Decisions, decisions. BTW, I can hear Tracy = mentally grumbling about the thought of adding any other component :-) =20 Rusty =20 =20 =20 ------=_NextPart_000_0071_01C34864.D714CD20 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

You could look at Bob Nuckolls's wiring diagrams = at aeroelectric.com and talk to him on the aeroelectric maillist. I have = his automotice alternator overvolt "crowbar" protection = circuit installed. Basically, you put the alternator field through a contactor = which is activated by a switch, and deactivated by a 5a breaker if overvolts are = sensed.

John Slade

Thanks John. I’m = familiar with electric Bob’s info. I had his crowbar device on my RV-8, = which had an externally regulated alternator. I considered installing his = internal regulator version on the RV-3, but just couldn’t justify the effort. I have absolutely NEVER heard of a modern alternator = causing damage from overvoltage, so I figure the risk is minimal. Worst = case, the EM-2 tells me I’m overvoltage, and I shut off the master. = That will allow the overvoltage to continue on the non-essential side of the buss, = but I can turn off the radio and transponder to save them. There really = isn’t anything else of significance to worry about. I’m still = considering my options, but at the very least, I’ll get rid of the current = switch for the excitation current. No good can be done with that = switch. Of course, since it’s there already, I could use it to power a = dedicated alternator contactor. Decisions, decisions. BTW, I can hear = Tracy mentally = grumbling about the thought of adding any other component :-)

Rusty

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