X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from relay01.roc.ny.frontiernet.net ([66.133.182.164] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTP id 945745 for flyrotary@lancaironline.net; Mon, 16 May 2005 11:24:24 -0400 Received-SPF: pass receiver=logan.com; client-ip=66.133.182.164; envelope-from=canarder@frontiernet.net Received: from filter01.roc.ny.frontiernet.net (filter01.roc.ny.frontiernet.net [66.133.183.68]) by relay01.roc.ny.frontiernet.net (Postfix) with ESMTP id B78173640D2 for ; Mon, 16 May 2005 15:23:40 +0000 (UTC) Received: from relay01.roc.ny.frontiernet.net ([66.133.182.164]) by filter01.roc.ny.frontiernet.net (filter01.roc.ny.frontiernet.net [66.133.183.68]) (amavisd-new, port 10024) with LMTP id 16416-02-38 for ; Mon, 16 May 2005 15:23:40 +0000 (UTC) Received: from [127.0.0.1] (67-137-82-124.dsl2.cok.tn.frontiernet.net [67.137.82.124]) by relay01.roc.ny.frontiernet.net (Postfix) with ESMTP id 399DE364D86 for ; Mon, 16 May 2005 15:23:39 +0000 (UTC) Message-ID: <4288BAF1.5080402@frontiernet.net> Date: Mon, 16 May 2005 10:23:29 -0500 From: Jim Sower User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040514 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Hot Alternator??? References: In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-Antivirus: avast! (VPS 0520-0, 05/16/2005), Outbound message X-Antivirus-Status: Clean X-Virus-Scanned: by amavisd-new-20040701 (2.0) at filter01.roc.ny.frontiernet.net I wanted overvoltage protection in my Alternator so I installed an additional Master Relay in the Alt B+ circuit. That allowed me to jump B+ to the field terminal on my internal regulator, simplifying the wiring of the charging system. If my Alt Switch is off, the Alternator is totally isolated from the rest of the electrical system regardless of the position of the Master Switch. Has several advantages ... Jim S. Ian Beadle wrote: > ----- Original Message ----- > *From:* Al Gietzen > *To:* Rotary motors in aircraft > *Sent:* Saturday, May 14, 2005 11:29 PM > *Subject:* [FlyRotary] Re: Hot Alternator??? > > For those of you in the know, is it normal for an alternator > to seep current and get warm when the field coil is powered > up? Is this something I need to fix? If so, should I cancel my > trip? I think it has probably been going on for a long time but... > > > The field current is controlled by the regulator, which is > usually internal. The regulator will only allow field current > if the armature is spinning and bat. below about 14 volts. A > small amount of current is allowed at start up via the little > red light to give initial voltage. > > In short get the regulator checked. > > Ian Beadle. > > Ian; > > With the alternator not running, the battery voltage will > always be below 14 volts; even with the charger on, so the > field current will flow. Dave has modified the internal > connection the same way I did to provide external feed to the > field windings. This does not run through the warning light. > So with battery voltage to the field, alternator not running; > I estimate it will draw 2-3 amps. Plenty to make the > alternator pretty warm after awhile. > > Also, I don’t think tripping a 5 amp breaker in field circuit > indicates anything wrong. With the battery a bit low and a, > say, 60A alternator spinning, the field could draw 5 amps. I > use a 7.5A breaker on my field current circuit. > > Al > > There should be a relay connected to D on the alternator, this > ensures that the field is only powered when the alternator is > spinning. > > Ian > ------------------------------------------------------------------------ > Internal Virus Database is out-of-date. > Checked by AVG Anti-Virus. > Version: 7.0.308 / Virus Database: 266.11.6 - Release Date: 6/05/2005 >