I can't agree with this more. The resistors are a neccesary evil. They provide some speed control, but more important they limit the inrush current to the motor (easily 400amps+ on the larger machines). This is tough on the motor, contactors and battery. Even though they waste energy, if there use is limited to short start up periods they result in improved performance. Before pulse width technology, the same sytem could be found on most large dc tracton motors - Trains etc.
RJ Kanary <rjkanary nauticom net> wrote:
Another thought, on the lack of armature resistors.They are there for a
reason. The inrush current, of dumping 36 volts into that non-turning
armature could very well have caused the 'L' Contactor a fatal meltdown.The
brushes won't care for it, either. I cannot overstate the importance, of
returning the controls to their original configuration. Yes, it is
primitive, by today's standards, it does waste a small amount of capacity,
until the resistors are bypassed, but , it was safe, and it worked.
RJ Kanary Bandi Bros. Inc.
Member TRNi Since 1998
ASE® Certified Master Auto Technician
rjkanary nauticom net
----- Original Message -----
From: "Tickners"
To:
Sent: Saturday, January 04, 2003 11:37 AM
Subject: (ET) help
> My tractor just died while blowing snow. We got a ton and I didn't get far
> at all before it died. I did some testing and initial R&R. My main
> disconnect was acting funny previously so I pulled that and cleaned it up,
> works better now. The lift and PTO still work fine.
>
> What happens is when I put it in forward the L contactor just clicks. It
has
> 36V at the big lugs and when I put it in forward the small lugs get about
> 12-15V like the voltage supplied to the coil is rapidly switching. When it
> first died it smelled hot and I stopped to check the blower motor and
drive
> motor with my hand. Then it would kind of edge forward in reverse and edge
> in reverse in forward, now it does nothing. Since it's dead in my driveway
> with about 16" of snow around it I tried jumping the L contactor coil from
> the big lug to the small lug, just to see if I could get the thing to move
> out of the way and it does the same thing, clicking. I thought maybe the
> contactor coil had partially shorted so I swapped the L contactor for the
2A
> contactor and it still does it.
>
> Now the fine print, I have an E15DA, and it seems like the wiring doesn't
> always match my shop manual. To compound that the PO had the reverse relay
> die so he replaced that with a DPDT toggle, which has worked fine for the
> past 2 years. So to go in reverse you flip the toggle and push the speed
> control forward. Also, the brake switch and seat switch have been
bypassed,
> and he told me that he had disabled the 1st 2 speeds since he thought the
> resistors up front just wasted battery power. I agree and using low gear
on
> the transaxle works just fine, but I have never sat down and figured how
he
> did that.
>
> Thanks for any help
>
>