RE: (ET) Problems with my E15, Need a little help

["Hazen, Dwight L" <hazen indiana edu>]

 I agree it sounds like the field voltage disappears when the throttle
is in the top position. Put a voltmeter on the field windings and run
the motor with the transmission in neutral. You should see full battery
voltage in the lower speed notches and then a drop in the voltage as the
you move the lever into the top position. If the voltage goes away or
drops to only a few volts then that is the problem. Running the motor
with out field voltage will burn the motor up.

To get max torque you need full field voltage (starting). To get max
speed and lower torque (running) you need to reduce the field voltage.

The BIG resistors in the front of the tractor are used for the armature
and are the main part of the speed control. They drop the voltage to the
armature to make the motor go slower. 

The field and armature work opposite each other. For starting you would
want full voltage on the field and lower voltage on the armature to
prevent flipping the tractor over (wheelie) on startup. Running in the
top notch is just the opposite, lower voltage on the field and full
voltage on the armature.  

The red circuit breaker is for the charger circuit and would not be part
of this problem.
 
 Dwight

Dwight L. Hazen, Indiana University, UITS 
Bloomington, In. 47408-7378
812-855-5367 IP phone 317-278-4014    
hazen indiana edu http://php.ucs.indiana.edu/~hazen/
Ham Radio wb9tlh arrl net http://wb9tlh.ampr.us
 

-----Original Message-----
From: SteveS [mailto:ssawtelle fcc net] 
Sent: Friday, October 25, 2002 9:03 AM
To: elec-trak cosmos phy tufts edu
Subject: Re: (ET) Problems with my E15, Need a little help

Hey Roy,

I'll take a stab at it.

If I understand it correctly, your E15 is very similiar to my E12S,
except
for the extra (3?) top 'clicks' in forward speed. The E15 gets the extra
speeds by using field weakening, which I stlll don't think I really
understand, but it somehow gives you extra speed by cutting down on the
field voltage. If I'm right so far, this makes sense, since instead of
cutting the field voltage down, it cuts the field off (bad connection,
broken wire, open resistor, etc), which will cause the armature to suck
tremendous current but not turn (at least I think so).

I suggest finding the resistor card (I don't have one so I can't help
there)
and looking for an open (probably a connector fell off). The manual for
the
E12S-E15  (available at Elec-Trak.org) has a good troubleshooting
diagrams.
You should be able to trace things through with a voltmeter.  Just don't
let
it run in the high current condition long as I think that is not good
for
the motor.

If all else fails let me know and I can come by and take a look.

SteveS
E12S



----- Original Message -----
From: "Roy Vanderhoef" <Roy Vanderhoef verizon net>
To: "'elek-trac Discussion group'" <>
Sent: Friday, October 25, 2002 9:07 AM
Subject: (ET) Problems with my E15, Need a little help


>
> Hi all I am having a problem with my E15
>
> When I push the control lever all the way up it starts to move and
then
> all of a sudden the usage meter pegs and it slows way down.  It does
not
> mater what gear I put it in the same thing happens.  If I push the
> control lever only a little ways up it runs fine.
>
> A little background  It has been running fine,  I was mowing grass and
> the battery charge meter was getting near the bottom side.  Still in
the
> green with no load.  Then all of a sudden with a little click, it just
> stopped.  I disconnected the power switch, and turned the key of and
> looked for a circuit breaker to reset.  Did not find one.  Then I
tried
> to start it again, and it ran ok in all but the top end of the control
> switch.
>
> I am a real novice at this Electrak thing so please that in mind when
> explaining what I need to do to trouble shoot and fix.  I do know the
> basics of using a VO Meter and how to solder.
>
> My gut felling is that some thing controlling the Electric flow is
> shorting on the wide open side
>
> By the way that little red button labeled 40 under the hood on the
back
> of the dash board.  Is that a fuse or a circuit breaker reset.  It did
> not feel like a reset switch (don't feel like it was depressing any
> thing, was not popped out etc) and I could not figure out how to open
it
> if it was a fuse.  That is I tried to turn it but it did not turn.
>
>
>