---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 09/17/15: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:28 AM - Re: Pitot Heat Ground (DougW) 2. 02:28 PM - Re: Pitot Heat Ground (DougW) ________________________________ Message 1 _____________________________________ Time: 10:28:38 AM PST US Subject: AeroElectric-List: Re: Pitot Heat Ground From: "DougW" Bob, This has been a rather lengthy thread. Being somewhat confused by various elements of the discussion, and as a recent acquirer of the Dynon heated pitot, I decided to look at the latest installation instructions. On page 3-1, it states to keep wires to the controller and between the controller and pitot away from any magnetometer/ADHRS, as well as audio devices. On page 3-2, it states "Do not connect the Black (Ground) wire to the airframe as a Ground connection." On page 3-4, the figure shows the black wire going "To permanent connection to aircraft ground" I could not find anywhere where it indicated that the metal case of the controller was and electrical ground for the controller. As a longtime follower of your comments and advice, I have avoided using the airframe as a ground except at one point on the firewall where it is grounded to the electrical system ground. For my installation, I will be generally following this comment of yours even though my magnetometer is in the tail cone, well away from the pitot heat wiring path: Were I designing such a beast, all power wiring between tube and box . . . and from box to ship's power would be on twisted pairs with the box providing EMC grounding only . . . power would float (this is the way the BIG guys do it). However, given the state of the conversation, I am wondering it a resistance measurement has been made between the proposed installation site and a common electrical ground point. Also, as the current must flow through the single +12v wire to power the controller/pitot provide the electromagnetic interference that the originator of this thread is trying to avoid? Regards, Doug Windhorn Read this topic online here: http://forums.matronics.com/viewtopic.php?p=447162#447162 ________________________________ Message 2 _____________________________________ Time: 02:28:10 PM PST US Subject: AeroElectric-List: Re: Pitot Heat Ground From: "DougW" Bob, This has been a rather lengthy thread. Being somewhat confused by various elements of the discussion, and as a recent acquirer of the Dynon heated pitot, I decided to look at the latest installation instructions. On page 3-1, it states to keep wires to the controller and between the controller and pitot away from any magnetometer/ADHRS, as well as audio devices. On page 3-2, it states "Do not connect the Black (Ground) wire to the airframe as a Ground connection." On page 3-4, the figure shows the black wire going "To permanent connection to aircraft ground" I could not find anywhere where it indicated that the metal case of the controller was and electrical ground for the controller. As a longtime follower of your comments and advice, I have avoided using the airframe as a ground except at one point on the firewall where it is grounded to the electrical system ground. For my installation, I will be generally following this comment of yours even though my magnetometer is in the tail cone, well away from the pitot heat wiring path: Were I designing such a beast, all power wiring between tube and box . . . and from box to ship's power would be on twisted pairs with the box providing EMC grounding only . . . power would float (this is the way the BIG guys do it). However, given the state of the conversation, I am wondering if a resistance measurement has been made between the proposed installation site and a common electrical ground point. I don't trust my airframe to conduct low resistance currents as it has been corrosion proofed internally. As the current for the heated pitot also must flow through the single +12v wire to power the controller/pitot, would this not provide the electromagnetic interference that the originator of this thread is attempting to avoid? Regards, Doug Windhorn Read this topic online here: http://forums.matronics.com/viewtopic.php?p=447172#447172 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.