X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 18 Nov 2013 08:44:46 -0500 Message-ID: X-Original-Return-Path: Received: from qmta12.westchester.pa.mail.comcast.net ([76.96.59.227] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTP id 6602827 for lml@lancaironline.net; Sun, 17 Nov 2013 07:07:31 -0500 Received-SPF: pass receiver=logan.com; client-ip=76.96.59.227; envelope-from=jmorgan1023@comcast.net Received: from omta05.westchester.pa.mail.comcast.net ([76.96.62.43]) by qmta12.westchester.pa.mail.comcast.net with comcast id qc2j1m0060vyq2s5Cc6vJo; Sun, 17 Nov 2013 12:06:55 +0000 Received: from [192.168.1.102] ([24.11.157.196]) by omta05.westchester.pa.mail.comcast.net with comcast id qc6v1m0034EXR5U3Rc6v9X; Sun, 17 Nov 2013 12:06:55 +0000 From: Jack Morgan Mime-Version: 1.0 (Apple Message framework v1283) Content-Type: multipart/alternative; boundary="Apple-Mail=_CC7A40AF-115E-45EA-84EB-59CB4A86D0BF" Subject: Surge protection for motors. X-Original-Date: Sun, 17 Nov 2013 07:06:56 -0500 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: <11FB4B35-2089-44BB-A7B3-00F7E9D6E733@comcast.net> X-Mailer: Apple Mail (2.1283) --Apple-Mail=_CC7A40AF-115E-45EA-84EB-59CB4A86D0BF Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=iso-8859-1 Hi Angier The most effective protection is usually done with conventional diodes = from the motor terminals to power and ground. The forward surge current = spec of the diodes is the spec to pay attention to. You will find a much = smaller diode than you would expect is effective and reliable. I'm a IVP guy so don't have a wiring diagram for your bird. If you = choose to forward your relay schematic to me, I would be happy to = confirm the above approach. I suspect others on the list already are = using the diode solution. In any case I would try and stay away from the = suppressor approach since it is more prone to failure especially from = improper "jump start" procedures. Hope this helps, Jack Morgan On Nov 16, 2013, at 6:28 PM, Lancair Mailing List wrote: > From: "Greenbacks, UnLtd." > Subject: Re: Surge protection > Date: November 16, 2013 10:15:37 AM EST > To: "Lancair Mailing List" >=20 >=20 > So what would be the best solution to protect our gear relays? > Bi-Directional Zener Transient Voltage Suppressors 18V 600W (for 14.5V = systems) like that from Perihelion Design, > or a metal oxide varistor? >=20 > Angier Ames > N4ZQ --Apple-Mail=_CC7A40AF-115E-45EA-84EB-59CB4A86D0BF Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=iso-8859-1 Hi = Angier

The most effective protection is usually done = with conventional diodes from the motor terminals to power and ground. = The forward surge current spec of the diodes is the spec to pay = attention to. You will find a much smaller diode than you would expect = is effective and reliable.

I'm a IVP guy so = don't have a wiring diagram for your bird. If you choose to forward your = relay schematic to me, I would be happy to confirm the above approach. I = suspect others on the list already are using the diode solution. In any = case I would try and stay away from the suppressor approach since it is = more prone to failure especially from improper "jump start" = procedures.

Hope this = helps,

Jack = Morgan


On Nov 16, 2013, at 6:28 = PM, Lancair Mailing List wrote:

From: "Greenbacks, = UnLtd." <Subject: Re: Surge = protection