AeroElectric-List Digest Archive

Fri 10/02/15


Total Messages Posted: 7



Today's Message Index:
----------------------
 
     1. 06:40 AM - Re: Grounding Question On dual Buss Dual Battery Aircraft (user9253)
     2. 07:31 AM - Re: Re: Grounding Question On dual Buss Dual Battery Aircraft (Kent or Jackie Ashton)
     3. 08:31 AM - Re: Grounding Question On dual Buss Dual Battery Aircraft (Robert L. Nuckolls, III)
     4. 08:45 AM - Re: Re: Grounding Question On dual Buss Dual Battery Aircraft (Robert L. Nuckolls, III)
     5. 02:55 PM - Re: Grounding Question On dual Buss Dual Battery Aircraft (Trent Heidtke)
     6. 03:16 PM - Re: Grounding Question On dual Buss Dual Battery Aircraft (Trent Heidtke)
     7. 03:18 PM - Re: Grounding Question On dual Buss Dual Battery Aircraft (Robert L. Nuckolls, III)
 
 
 


Message 1


  • INDEX
  • Back to Main INDEX
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 06:40:04 AM PST US
    Subject: Re: Grounding Question On dual Buss Dual Battery Aircraft
    From: "user9253" <fransew@gmail.com>
    Yes, you are being overly cautious about grounding and might create more serious problems. Connect the negative terminal of each battery to a common ground point and connect the negative side of all loads to that common point. Doing that will not create ground loops. Consider dual alternators instead of dual batteries, perhaps Z-13/8. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=447588#447588


    Message 2


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 07:31:10 AM PST US
    Subject: Re: Grounding Question On dual Buss Dual Battery
    Aircraft
    From: Kent or Jackie Ashton <kjashton@vnet.net>
    Ditto on avoiding ground loops (a small difference in ground potential at different ground points that causes a small current loop). In my Cozy, I pulled was puzzled for years by a squirrelly fuel pressure indicator. The FP sender was grounded at the engine, FP gauge grounded up front. It is really a problem with gauging systems that use tiny currents. Probably not so much with big-amp devices. -Kent > On Oct 2, 2015, at 9:38 AM, user9253 <fransew@gmail.com> wrote: > > > Yes, you are being overly cautious about grounding and might create more serious problems. Connect the negative terminal of each battery to a common ground point and connect the negative side of all loads to that common point. Doing that will not create ground loops. > Consider dual alternators instead of dual batteries, perhaps Z-13/8. > > -------- > Joe Gores > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=447588#447588 > > > > > > > > > >


    Message 3


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 08:31:44 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Grounding Question On dual Buss Dual Battery
    Aircraft At 01:13 AM 10/2/2015, you wrote: >Hey Trent, my favorite aeroplane! > >What power plant? > >On 2 October 2015 at 01:22, Trent Heidtke ><<mailto:theidtke@cox.net>theidtke@cox.net> wrote: > >Hello everyone, I am new here, building a >Prescott Pusher, and have a question.=C2 My plane >is totally electric dependent and so I have been >following the Aero Connection Diagram Z-19 which >addresses an outline for a dual battery, single >alternator, and totally electronic fuel >injection system.=C2 Additionally, I have >subscribed 100% to the wiring philosophy whereby >all powered device grounds go directly to the >battery running the device instead of the >massive common ground to frame approach Please don't do this. See Figure Z-15. ONE ground for all potential antagonists on the firewall . . . batteries ground here too. This ground gets a good connnection to the welded frame as well. ONE ground for all potential victims on the panel with a single feed path between panel ground and firewall ground. It's okay to use the frame as a ground for remotely located antagonists . . . just don't run battery charging currents or starter currents through the frame. Had the pleasure of working with Mr. Prescott during my first tenure at Beech in the Targets Division. Bob . . .


    Message 4


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 08:45:23 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Grounding Question On dual Buss Dual Battery
    Aircraft At 09:29 AM 10/2/2015, you wrote: ><kjashton@vnet.net> > >Ditto on avoiding ground loops (a small difference in ground >potential at different ground points that causes a small current >loop). In my Cozy, I pulled was puzzled for years by a squirrelly >fuel pressure indicator. The FP sender was grounded at the engine, >FP gauge grounded up front. It is really a problem with gauging >systems that use tiny currents. Probably not so much with big-amp devices. Actually, it was the BIG amp devices that generated the difference in potential between what was expected to be same-voltage-grounds. This was a common problem in early LongEz ships with no starter and a 30-40a alternator. The builder RATED his ground return from crankcase to battery(-) for ALTERNATOR currents . . . so 10A wire at 1 milliohm per foot x 15ft long x 30A would generate as much as 1/2 volt difference between CRANKCASE ground and BATTERY ground. Hence, engine grounded 'senders' would produce strange and variable readings as the alternator loads varied and only read correctly when the alternator was off. Problem was still there . . . only much smaller if the builder added a starter and the crankcase ground was up-sized to 4 or 2AWG. Seldom a problem on BIG airplanes. A Beechjet measures about .001 ohm from stem to stern . . . enough to experience significant differences in 'ground' potentials during lighting strikes . . . but seldom an issue for more mundane current flows circulating between system grounds. This is why potential victims are grounded at various locations about the airframe . . . thusly . . . http://tinyurl.com/odvpk6z . . . but the ground systems in smaller airplanes and of course composite aircraft are not so robust. Hence the need for artful grounding architectures. Bob . . .


    Message 5


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 02:55:05 PM PST US
    From: "Trent Heidtke" <theidtke@cox.net>
    Subject: Grounding Question On dual Buss Dual Battery Aircraft
    Hi Bob, The Prescott Pusher I am building is using a Mazda 20B 3-rotor engine. I live in the AZ desert so particularly in the summer when going North to Prescott, Sedona, or Flagstaff I need a bit more than 200 HP/60 inch prop (original spec=99d items) to get me off the ground. Mazda 3-rotor was about the only weight/HP choice to keep W/B about as close to original as possible. Still about a year and a half from finishing but everything has been on it to check fit/function. Just trying to make sure I am doing wiring right at this point. Trent From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob Verwey Sent: Thursday, October 01, 2015 11:14 PM Subject: Re: AeroElectric-List: Grounding Question On dual Buss Dual Battery Aircraft Hey Trent, my favorite aeroplane! What power plant? On 2 October 2015 at 01:22, Trent Heidtke <theidtke@cox.net> wrote: Hello everyone, I am new here, building a Prescott Pusher, and have a question. My plane is totally electric dependent and so I have been following the Aero Connection Diagram Z-19 which addresses an outline for a dual battery, single alternator, and totally electronic fuel injection system. Additionally, I have subscribed 100% to the wiring philosophy whereby all powered device grounds go directly to the battery running the device instead of the massive common ground to frame approach (I have a metal sub-frame with composite skins over it). As illustrated in Diagram Z-19, I have set up primary and secondary batteries and busses with diodes so that #1 fuel pump and ECU have power all the time from #1 battery. In case of battery failure, flipping secondary power switch sends power from #2 battery through the diode to #1 fuel pump and ECU. The challenge is that if I remain pure to the philosophy of power and ground for any device go to/from the same battery, #1 fuel pump and ECU are not grounded and so if secondary power switch is turned on, pump does not work..obviously since it is not grounded to #2 battery. So I could add a switch to switch grounds (another level of complexity), or, wire the grounds together at the fuel pump connection in the back of the plane. Which approach is better? It is not really addressed in the diagram.that I can interpret anyway. Maybe I am being overly cautious about the grounding thing but am trying desperately not to end up with ground loops =93 about 70% wired and so far so good, except for this condition. Any and all help appreciated.. Thank you Trent ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List tp://forums.matronics.com _blank">http://www.matronics.com/contribution -- Best... Bob Verwey


    Message 6


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 03:16:06 PM PST US
    From: "Trent Heidtke" <theidtke@cox.net>
    Subject: Grounding Question On dual Buss Dual Battery
    Aircraft Thank you Bob and everyone that replied to my request for help. It is very much appreciated. While I can read and implement schematics done by people way more intelligent than I, it is hard sometimes to discern the finer points that years of experience yields those who have been there and lived that. Based on the feedback, I am commencing to rewire the parts that need to be changed to comply more with the wisdom shared here. Regarding the Pusher project, it has been an amazing journey and both Ole Sindberg, and Tom Prescott have been immensely helpful (only 2 Prescott Pushers flying in the US to my knowledge). I hope that first flight will be in about 18 months now that I am back full time on the project. At present though, the wiring help will ensure success in that department so thank you all again. The next big challenge after wiring is making sure the Mazda 20B installation goes well. Glad there is an engine thread/forum as well for that=85. ;-) Trent From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Friday, October 02, 2015 8:28 AM Subject: Re: AeroElectric-List: Grounding Question On dual Buss Dual Battery Aircraft At 01:13 AM 10/2/2015, you wrote: Hey Trent, my favorite aeroplane! What power plant? On 2 October 2015 at 01:22, Trent Heidtke <theidtke@cox.net> wrote: Hello everyone, I am new here, building a Prescott Pusher, and have a question.=C2 My plane is totally electric dependent and so I have been following the Aero Connection Diagram Z-19 which addresses an outline for a dual battery, single alternator, and totally electronic fuel injection system.=C2 Additionally, I have subscribed 100% to the wiring philosophy whereby all powered device grounds go directly to the battery running the device instead of the massive common ground to frame approach Please don't do this. See Figure Z-15. ONE ground for all potential antagonists on the firewall . . . batteries ground here too. This ground gets a good connnection to the welded frame as well. ONE ground for all potential victims on the panel with a single feed path between panel ground and firewall ground. It's okay to use the frame as a ground for remotely located antagonists . . . just don't run battery charging currents or starter currents through the frame. Had the pleasure of working with Mr. Prescott during my first tenure at Beech in the Targets Division. Bob . . .


    Message 7


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 03:18:03 PM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Grounding Question On dual Buss Dual Battery
    Aircraft At 04:53 PM 10/2/2015, you wrote: >Hi Bob, >The Prescott Pusher I am building is using a >Mazda 20B 3-rotor engine.=C2 I live in the AZ >desert so particularly in the summer when going >North to Prescott, Sedona, or Flagstaff I need a >bit more than 200 HP/60 inch prop (original >spec=99d items) to get me off the >ground.=C2 Mazda 3-rotor was about the only >weight/HP choice to keep W/B about as close to >original as possible.=C2 Still about a year and a >half from finishing but everything has been on >it to check fit/function.=C2 Just trying to make >sure I am doing wiring right at this point. >Trent Understand. Have you crafted a load analysis and prioritized loads under various operating and failure modes? Bob . . .




    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
  • 7-Day List Browse
  •   http://www.matronics.com/browse/aeroelectric-list
  • Browse AeroElectric-List 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.

    -- Please support this service by making your Contribution today! --