Re: (ET) Ok, my E20 is insane

["RJ Kanary" <rjkanary nauticom net>]

    CR413 and 414 are also prime suspects. CR412 and CR 6 are dark horse
possibilities.The clamping diode for the FW Relay Coil, {CR 406} ,were it
open, would have some spike developing potential, that might  cause other
components to get upset.
     The first time I had an edge card connector fail, it made field
weakening in Reverse possible. Not the thing to have happening when you
don't expect it <G>
    Also, ensure that there are no issues with the small wires that attach
to the large terminals on the armature contactors. High resistance there
will also reduce field voltage.

----- Original Message ----- 
From: "Chris Zach" <czach computer org>
To: "RJ Kanary" <rjkanary nauticom net>
Cc: "Elec-trak list" <elec-trak cosmos phy tufts edu>
Sent: Thursday, July 29, 2004 9:48 PM
Subject: Re: (ET) Ok, my E20 is insane


> Pulled the edge connector and checked the main diodes. They do look
> good, replaced diodes 402 and 403 just because.
>
> It's an AA model.
>
> Maybe the other diodes have blown up.
>
> Chris
>
>
> RJ Kanary wrote:
>
> >     If you E-20 is an AA or BA model , or even an early CA,{Eight motor
> > speeds, instead of seven. } ,  I would suspect the edge card connector
has
> > split apart . Intermittants in this area will drive YOU insane ? <G>
> >
> > ----- Original Message ----- 
> > From: "Chris Zach" <czach computer org>
> > To: "Elec-trak list" <elec-trak cosmos phy tufts edu>
> > Sent: Thursday, July 29, 2004 9:31 PM
> > Subject: (ET) Ok, my E20 is insane
> >
> >
> >
> >>Ok, this is really weird.
> >>
> >>Right now my E20 is in an odd place. If you put it in neutral and press
> >>down on the pedal, the motor comes up to full speed immediately. That's
> >>on throttle setting 1.
> >>
> >>Go to setting two. You hear a click, but the motor spins at the same
> >>speed. Same with setting 3 and 4. A click each time from the contactors
> >>but no change in motor speed. Speed 4 is normally full armature, full
> >
> > field.
> >
> >>In speed 5,6,7,8 you can hear the motor speed up. Wahoo; we're running
> >>with proper field weakening. But it's almost as if cruise control is
> >>halfway engaged in the lower speeds, locking in all contactors. Except
> >>that the contactors are clicking in; you can hear them. They're not
> >>locked on.
> >>
> >>It gets worse. Switch to reverse. Now you will hear the motor spinning
> >>backwards slowly thru the gears, however there is *NO* field to speak 
> >>of
> >>as the armature current is way off the chart. And after a few seconds
> >>the motor thermal breaker trips.
> >>
> >>Any idea what the heck is going on here?
> >>
> >>Chris
> >>
> >>_______________________________________________
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> >>Elec-trak cosmos phy tufts edu
> >>https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
> >>
> >
> >
> >
> >
>