X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 30 Apr 2012 05:58:42 -0400 Message-ID: X-Original-Return-Path: Received: from imr-da03.mx.aol.com ([205.188.105.145] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5514659 for lml@lancaironline.net; Sun, 29 Apr 2012 17:42:56 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.105.145; envelope-from=Sky2high@aol.com Received: from mtaomg-ma01.r1000.mx.aol.com (mtaomg-ma01.r1000.mx.aol.com [172.29.41.8]) by imr-da03.mx.aol.com (8.14.1/8.14.1) with ESMTP id q3TLgIbe001241 for ; Sun, 29 Apr 2012 17:42:18 -0400 Received: from core-mtc004b.r1000.mail.aol.com (core-mtc004.r1000.mail.aol.com [172.29.235.13]) by mtaomg-ma01.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 4155EE000087 for ; Sun, 29 Apr 2012 17:42:18 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Sun, 29 Apr 2012 17:42:18 -0400 (EDT) Subject: Re: [LML] contactor X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_b44a.7a26c0e6.3ccf0fb9_boundary" X-Mailer: AOL 9.6 sub 168 X-Originating-IP: [67.175.156.123] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:400978816:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d29084f9db5ba4bc6 --part1_b44a.7a26c0e6.3ccf0fb9_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Ed, The benefit is the direct #2 or #4 cabling to the starter relay (and then to the starter) while the Master relay to main bus is then a much smaller wire sized for, say, your max alternator load current (like 70 amp). The disadvantage is the single point of failure. If the starter relay should become stuck in the closed position, there is a lot of damage possible because you could not shut down power via the master sw/relay. Did you run the starter coil circuit through a pullable breaker or is it just through the highly reliable start position on the ignition switch? Well, at least they never fail. Oh, that's right, the coil is fed + voltage from the hot side of the contactor and all the switch does is ground the other side of the coil - what could possibly go wrong?..... Grayhawk In a message dated 4/29/2012 12:18:59 P.M. Central Daylight Time, egraylaw@swbell.net writes: One option no one mentions is power to the start contactor directly from the battery. When I routed 12v. from battery (Odyssy 680) to main relay then to starter contactor, I had very slow cranking (IO360 on Lancair 360). Battery direct to starter relay and no problem. Bingelis book shows this option. Why run starter current through master relay? How often does a start contactor weld itself closed? If it does the battery will go flat pretty quick-am I correct? Ed Gray Dallas --part1_b44a.7a26c0e6.3ccf0fb9_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Ed,

The benefit is the direct #2 or #4 cabling to the starter relay (= and=20 then to the starter) while the Master relay to main bus is then a much smal= ler=20 wire sized for, say, your max alternator load current (like 70 amp).

The disadvantage is the single point of failure. If the starter = relay=20 should become stuck in the closed position, there is a lot of damage possib= le=20 because you could not shut down power via the master sw/relay. D= id=20 you run the starter coil circuit through a pullable breaker or is it just= =20 through the highly reliable start position on the ignition switch? We= ll,=20 at least they never fail. Oh, that's right, the coil is fed + voltage= from=20 the hot side of the contactor and all the switch does is ground the other s= ide=20 of the coil - what could possibly go wrong?.....

Grayhawk

In a message dated 4/29/2012 12:18:59 P.M. Central Daylight Time,=20 egraylaw@swbell.net writes:

One option no one me= ntions is=20 power to the start contactor directly from the battery. When I rout= ed=20 12v. from battery (Odyssy 680) to main relay then to starter contactor, I= had=20 very slow cranking (IO360 on Lancair 360). Battery direct to starte= r=20 relay and no problem. Bingelis book shows this option. Why ru= n=20 starter current through master relay? How often does a start contac= tor=20 weld itself closed? If it does the battery will go flat pretty quic= k-am=20 I correct?

Ed Gray Dallas=20

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