X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 18 Dec 2013 15:45:15 -0500 Message-ID: X-Original-Return-Path: Received: from argon.lunarpages.com ([216.97.227.30] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6644219 for lml@lancaironline.net; Wed, 18 Dec 2013 13:47:40 -0500 Received-SPF: pass receiver=logan.com; client-ip=216.97.227.30; envelope-from=thorn@starflight.aero Received: from 65-128-56-43.hlrn.qwest.net ([65.128.56.43]:50961 helo=VAlien2) by argon.lunarpages.com with esmtpa (Exim 4.77) (envelope-from ) id 1VtM9A-0002It-Ex for lml@lancaironline.net; Wed, 18 Dec 2013 10:47:05 -0800 From: "Valin & Allyson Thorn" X-Original-To: "'Lancair Mailing List'" X-Original-Cc: "Valin & Allyson Thorn" Subject: Shielded Wiring Best Practices X-Original-Date: Wed, 18 Dec 2013 11:46:55 -0700 X-Original-Message-ID: <008201cefc21$865d39e0$9317ada0$@starflight.aero> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0083_01CEFBE6.DA00ABD0" X-Mailer: Microsoft Outlook 15.0 Content-Language: en-us Thread-Index: Ac78IOxRqomJrkjlR6mjDyxzg0PO3g== X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - argon.lunarpages.com X-AntiAbuse: Original Domain - lancaironline.net X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - starflight.aero X-Get-Message-Sender-Via: argon.lunarpages.com: authenticated_id: thorn@starflight.aero This is a multipart message in MIME format. ------=_NextPart_000_0083_01CEFBE6.DA00ABD0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hey LML gang, We're not sure how best to implement shielded wiring out to components in our airplane. We're wanting to ensure we don't have a bunch of electromagnetic interference (EMI) that might mess with sensitive components like the ADHARS magnetometer. Examples of EMI sources would be power lines running to motors (flaps, hydraulic pump, AC fans, AC compressor) and components with rapidly changing electrical current (strobe lights, HID lights). My understanding is that Twisted Shielded Pair (TSP) cables are ideal for DC power transmission since the magnetic fields mostly cancel each other out and shield absorbs what's left. I'm not sure, though, how best to implement their termination at the ground/negative bus and positive bus -- at the switch in most cases, then line running to the circuit breakers or fuse. At some point, the separate conductors have to leave the shielded jacket and run to these separate connections which seems to defeat the benefits of the TSP. Considering this, would it be better to use two individually shielded Tefzel jacketed wires and twist them together for the part of the path where they run together and then they each have their individual shields as they separate and run to their connections? What are the best practices on actually implementing shielded wiring for power and signal transmission in our airplanes.? Thanks, Valin Thorn Legacy Project Boulder, Colorado ------=_NextPart_000_0083_01CEFBE6.DA00ABD0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Hey LML = gang,

We’re not sure how best to = implement shielded wiring out to components in our airplane. We’re wanting to ensure = we don’t have a bunch of electromagnetic interference (EMI) that = might mess with sensitive components like the ADHARS magnetometer. Examples of EMI sources would = be power lines running to motors (flaps, hydraulic pump, AC fans, AC = compressor) and components with rapidly changing electrical current = (strobe lights, HID lights).

My understanding is that Twisted = Shielded Pair (TSP) cables are ideal for DC power transmission since the = magnetic fields mostly cancel each other out and shield absorbs = what’s left. = I’m not sure, though, how best to implement their = termination at the ground/negative bus and positive bus -- at the = switch in most cases, then line running to the circuit breakers or = fuse. At some point, the = separate conductors have to leave the shielded jacket and run to these = separate connections which seems to defeat the benefits of the = TSP.

Considering this, would it be better = to use two individually shielded Tefzel = jacketed wires and twist them together for the part of the path where = they run together and then they each have their individual shields as = they separate and run to their connections?

What are the best practices on = actually implementing shielded wiring for power and signal transmission = in our airplanes…?

Thanks,

Valin Thorn

Legacy = Project

Boulder, = Colorado

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