Results 1 to 10 of 10

Thread: Can you remove the ground from Bosch alternator?

  1. #1
    Join Date
    Jul 2006
    Location
    East-South-East Girt-By-Sea
    Posts
    17,668
    Total Downloaded
    1.20 MB

    Can you remove the ground from Bosch alternator?

    Is it possible to modify a regular automotive alternator i.e. Bosch so that it runs a totally isolated charging system, not subect to the vehicle ground (chassis)?

    I'm wondering if it can be modified internally so the alternator case/body is isolated or would I have to make electically isolated mountings?

    Just looking at options for my ex-SADF SIIB and running the camper functions on 24V and the car systems on 12V

    You won't find me on: faceplant; Scipe; Infragam; LumpedIn; ShapCnat or Twitting. I'm just not that interesting.

  2. #2
    Join Date
    Nov 2009
    Location
    Western Victoria
    Posts
    14,101
    Total Downloaded
    0
    I have dual voltage 12V/24V devices in the 101 using the same ground. Why do you need to isolate the alternator and run a separate ground?

  3. #3
    Join Date
    Jul 2006
    Location
    East-South-East Girt-By-Sea
    Posts
    17,668
    Total Downloaded
    1.20 MB
    I just want to know if its possible.

    If I'm correct in my understanding, the 100AMP CAV alternator on Aussie Land Rover FFR are totally isolated and I was considering using the same distribution box, but connect it to a regular Bosch 28V alternator.

    You won't find me on: faceplant; Scipe; Infragam; LumpedIn; ShapCnat or Twitting. I'm just not that interesting.

  4. #4
    Join Date
    Apr 2009
    Location
    Crafers West South Australia
    Posts
    11,732
    Total Downloaded
    0
    While it would be conceivably possible, by isolating the negative diode plate and the regulator earth, I'd think there are better solutions like a 24-12V reducer for a few 12V functions. If you opened up an early model Bosch alternator and studied the way the positive diode plate is isolated, then salvaged the insulators out of another diode pack and drilled out the mounting holes to isolate the negative one too. Nothing massively complicated I suspect.

  5. #5
    Join Date
    Jul 2006
    Location
    East-South-East Girt-By-Sea
    Posts
    17,668
    Total Downloaded
    1.20 MB
    The whole vehicle system is currently 12V so more than just a few 12V bits.

    Was really just thinking out loud. If its a drama modifying the internals, isolating the mountings with ceramic or nylon bushes and washers would be easiest.

    The other issue, would be if it's possible to use the Army distribution box with the negative grounded?

    You won't find me on: faceplant; Scipe; Infragam; LumpedIn; ShapCnat or Twitting. I'm just not that interesting.

  6. #6
    Join Date
    Apr 2009
    Location
    South Sydney
    Posts
    2,499
    Total Downloaded
    0
    I don't see why you need a separate ground circuit... unless I'm missing a massive part of my engineering degree and work as an electrical trade assistant

    Just run an active wire to where your 24V circuit starts, ground it all to the chassis.

    Cheers
    Will

  7. #7
    Join Date
    Apr 2009
    Location
    Crafers West South Australia
    Posts
    11,732
    Total Downloaded
    0
    Quote Originally Posted by Lotz-A-Landies View Post
    The whole vehicle system is currently 12V so more than just a few 12V bits.

    Was really just thinking out loud. If its a drama modifying the internals, isolating the mountings with ceramic or nylon bushes and washers would be easiest.

    The other issue, would be if it's possible to use the Army distribution box with the negative grounded?
    If you want the simplest isolated alternator, remove the diode pack and regulator, remote mount them and run a 3 core cable from the stator windings to the diode pack. They may need fan cooling or a bigger heatsink. But I can't see why you couldn't run a common earth for both voltages.

  8. #8
    Join Date
    Jul 2006
    Location
    Seaforth NSW
    Posts
    933
    Total Downloaded
    0
    I converted a number of Bosch alternators (35A and later 55A) to positive ground to charge two batteries (one negative ground, the other positive ground) to operate my 24V Aircraft radial engine starter motor driven electric winch. Two alternators, two mounts and a bit of electrickery - how did we do it?

    That gives you 24V over the two batteries, one 12V negative earth for polarity specific electronic equipment and ignition and one 12V positive earth for insulated equipment or polarity selectable like Engel fridges and you can use it to run spotlights, etc that don't have polarity requirements.

    Bob

  9. #9
    Join Date
    Jul 2006
    Location
    East-South-East Girt-By-Sea
    Posts
    17,668
    Total Downloaded
    1.20 MB
    Tell me that this is not electrically isolated?

    Attached Images Attached Images

    You won't find me on: faceplant; Scipe; Infragam; LumpedIn; ShapCnat or Twitting. I'm just not that interesting.

  10. #10
    Join Date
    Jul 2006
    Location
    East-South-East Girt-By-Sea
    Posts
    17,668
    Total Downloaded
    1.20 MB
    So for the electrical gurus, in the diagramme above is it OK to use chassis ground of an Bosch 28V alternator in the Army FFR distribution box?

    Yes I would still run a dedicated negative lead from the alternator to the Distribution box, in addition to the chassis ground.

    You won't find me on: faceplant; Scipe; Infragam; LumpedIn; ShapCnat or Twitting. I'm just not that interesting.

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Search AULRO.com ONLY!
Search All the Web!