X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [66.219.56.253] (HELO mail.qnsi.net) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3639347 for flyrotary@lancaironline.net; Mon, 11 May 2009 23:35:34 -0400 Received-SPF: none receiver=logan.com; client-ip=66.219.56.253; envelope-from=bhughes@qnsi.net Return-Receipt-To: "Bobby J. Hughes" MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C9D2BB.262CF96E" Subject: Starter Problem \ Question Disposition-Notification-To: "Bobby J. Hughes" Content-class: urn:content-classes:message Date: Mon, 11 May 2009 22:35:59 -0600 x-mimeole: Produced By Microsoft Exchange V6.5 Message-ID: <74120FDE88CAFE4DBDA8814BCE20A3F315E173@qnsi-mail.qnsi.net> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: Starter Problem \ Question thread-index: AcnSuyXfenaeeXw0Ts+/iGdKwT5NGA== From: "Bobby J. Hughes" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01C9D2BB.262CF96E Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Is it possible for a starter to keep drawing current after engine start without being engaged to the starter wheel? I was seeing a 38A draw today during ground runs with only fuel, spark, EM2/3 and engine monitor turned on. Normally I see about 15A in this condition. During ground runs last week and running on my backup battery\ wiring I popped an 80A ANL fuse several minutes after engine start. At the time I suspected a hot polyfuse in a crowbar circuit for the alternator triggered the event. After studying my wiring diagram I determined the crowbar opening could not cause the fuse to fail. The only item capable of blowing this fuse is the starter. The starter coil wire is in parallel with a firewall contactor coil wire. Both coil wires go to a starter switch fused at 10A. I suspect a starter problem is keeping voltage on the coil lead and keeping the firewall contactor closed after engine start. My firewall contactor is not the usually starter contactor with the small wiring terminal for the starter. It's a conventional contactor but rated for high current. This may be part of the problem. If the starter checks out then I will use a DC amp meter on the starter lead. I may also add a run-on light to the coil leads. =20 Any input would be appreciated. =20 Bobby =20 ------_=_NextPart_001_01C9D2BB.262CF96E Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Is it = possible for a=20 starter to keep drawing current after engine start without being engaged = to the=20 starter wheel? I was seeing a 38A draw today during ground runs = with only=20 fuel, spark, EM2/3 and engine monitor turned on. Normally I see about = 15A in=20 this condition. During ground runs last week and running on my = backup=20 battery\ wiring I popped an 80A ANL fuse several minutes after = engine=20 start. At the time I suspected a hot polyfuse in a crowbar = circuit for=20 the alternator triggered the event. After studying my wiring = diagram I=20 determined the crowbar opening could not cause the fuse to fail. The = only item=20 capable of blowing this fuse is the starter. The starter coil wire is in = parallel with a firewall contactor coil wire. Both coil wires go to = a=20 starter switch fused at 10A. I suspect a starter problem is keeping = voltage on=20 the coil lead and keeping the firewall contactor closed after engine=20 start. My firewall contactor is not the usually starter = contactor with=20 the small wiring terminal for the starter. It's a conventional contactor = but=20 rated for high current. This may be part of the problem. If the = starter=20 checks out then I will use a DC amp meter on the starter lead. I may = also add a=20 run-on light to the coil leads.
 
Any = input would be=20 appreciated.
 
Bobby
 
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