X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from EXHUB003-3.exch003intermedia.net ([207.5.74.110] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTPS id 3639693 for flyrotary@lancaironline.net; Tue, 12 May 2009 10:07:04 -0400 Received-SPF: none receiver=logan.com; client-ip=207.5.74.110; envelope-from=jwhaley@datacast.com Received: from EXVMBX003-5.exch003intermedia.net ([207.5.74.45]) by EXHUB003-3.exch003intermedia.net ([207.5.74.110]) with mapi; Tue, 12 May 2009 07:06:27 -0700 From: Jeff Whaley To: Rotary motors in aircraft Date: Tue, 12 May 2009 07:06:27 -0700 Subject: RE: [FlyRotary] Starter Problem \ Question Thread-Topic: [FlyRotary] Starter Problem \ Question Thread-Index: AcnSs0yC/goWSXcyTH24b2bnlios3AAVmghQ Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_C03ABB0A7362B84BB53D544B3C305E0EF65CB85C2DEXVMBX0035exc_" MIME-Version: 1.0 --_000_C03ABB0A7362B84BB53D544B3C305E0EF65CB85C2DEXVMBX0035exc_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Bobby, I have seen similar problems with contactors/relays in the past, spe= cifically the automotive starter relays that are chassis grounded and requi= re +12V to activate the relay ... if the +12V (battery voltage) is weak the= se relays will stick ON. In my case, the starter would stay engaged so ther= e was no doubt about what was happening but the engine was not running ... = in your case with the engine running you may not be able tell. Why don't you run the starter for a second or two, but do not let the engin= e start (turn fuel off for example) then check your amp meter after disenga= ge? Jeff From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf Of Bobby J. Hughes Sent: Tuesday, May 12, 2009 12:36 AM To: Rotary motors in aircraft Subject: [FlyRotary] Starter Problem \ Question Is it possible for a starter to keep drawing current after engine start wit= hout being engaged to the starter wheel? I was seeing a 38A draw today duri= ng ground runs with only fuel, spark, EM2/3 and engine monitor turned on. N= ormally 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 minu= tes 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 d= iagram I determined the crowbar opening could not cause the fuse to fail. T= he 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 v= oltage on the coil lead and keeping the firewall contactor closed after eng= ine start. My firewall contactor is not the usually starter contactor with = the small wiring terminal for the starter. It's a conventional contactor bu= t rated for high current. This may be part of the problem. If the starter c= hecks out then I will use a DC amp meter on the starter lead. I may also ad= d a run-on light to the coil leads. Any input would be appreciated. Bobby --_000_C03ABB0A7362B84BB53D544B3C305E0EF65CB85C2DEXVMBX0035exc_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Bobby, I have seen similar problems with contactors/relays i= n the past, specifically the automotive starter relays that are chassis groun= ded and require +12V to activate the relay … if the +12V (battery voltage= ) is weak these relays will stick ON. In my case, the starter would stay engaged= so there was no doubt about what was happening but the engine was not running = … in your case with the engine running you may not be able tell.

Why don’t you run the starter for a second or two, but= do not let the engine start (turn fuel off for example) then check your amp me= ter after disengage?  Jeff

 

From: Rotary motors= in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes
Sent: Tuesday, May 12, 2009 12:36 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Starter Problem \ Question

 

Is it possible for a starter to keep drawing current after engine start withou= t being engaged to the starter wheel? I was seeing a 38A draw today duri= ng ground runs with only fuel, spark, EM2/3 and engine monitor turned on. Norm= ally 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 eve= nt. 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. Th= e 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 star= ter contactor with the small wiring terminal for the starter. It's a convention= al 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.

 

Any input would be appreciated.

 

Bobby

 

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