---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 04/29/24: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:53 AM - Re: Primary Power Diagram RV-14 (Mudfly) 2. 04:37 PM - Re: Primary Power Diagram RV-14 (user9253) ________________________________ Message 1 _____________________________________ Time: 03:53:58 AM PST US Subject: AeroElectric-List: Re: Primary Power Diagram RV-14 From: "Mudfly" I'm finally getting around to actually running wires for my primary power system. In the process, I discovered something that I missed earlier and would like some second opinions before I make any changes. Through all my previous primary power system revisions I included a diode between the Main Power Bus and the Avionics/Essential Bus. As I was running wires for this diode it occurred to me the diode may not be required. My reasoning: The avionics relay is normally open. When the Batt/Off/Esntl switch is placed to Esntl, power is removed from the Avionics Bus relay and it should open. This should prevent current flow from the Avionics/Essential Bus that is now being fed from the Stby Alt, or the battery, through the Essential bus relay. One "non-std" configuration I did consider would be the Batt/Off/Esntl switch placed to the Esntl position but the Pri Alt/Stby Alt switch was left in the Pri Alt position. IF, the Pri Alt is still operating, the Main Pwr Bus and the Esntl Bus would continue to be fed by the Pri Alt. However, The batt contactor is now open due to the due to the Batt/Off/Esntl switch in the Esntl position. In this scenerio, both the Avionics bus realy and the Esntl bus relay are closed at the same time (non-std). The battery is now getting charge power "backwards" through the Esntl bus relay . Now that I think about it, that scenario would also occur with a diode in place. Anyway, anything else I may need to consider before I remove the diode? The attached power digram shows the diode in question circled in red. Thanks for your inputs. Shawn Read this topic online here: http://forums.matronics.com/viewtopic.php?p=513526#513526 Attachments: http://forums.matronics.com//files/pri_pwr_337.pdf ________________________________ Message 2 _____________________________________ Time: 04:37:18 PM PST US Subject: AeroElectric-List: Re: Primary Power Diagram RV-14 From: "user9253" The simpler the electrical system is, the more reliable it will be. Fewer switches and relays results in less components to fail. In an emergency, the pilot's mind will go blank and he won't remember what switches do what. Without the diode, the relays could feed power to the main power bus and even to the starter if switches are in the wrong position. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=513530#513530 ------------------------------------------------------------------------------------- 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.