RE: (ET) e-15 eats reverse relays

["Pieter Litchfield" <plitch attglobal net>]

Thanks for the prompt reply - your inpt is very helpful.  I will just be
sure to wait until all the motor noises die out when reversing direction!
Your remark about a chronic fault of ET's being one of reversing under 
heavy
load sounds familiar - my loader (driven by a big 36v motor of course) will
occasionally cause a reversing of the speed control - moving the lever into
reverse while the loader motor is running will cause the tractor to move
forward!  I have since learned not to change direction without shutting off
the PTO switch first.  So now, I will coast to a complete stop, shut off 
the
PTO, then reverse!  Oh yes - the weight of the loader did snap a spindle
too, so now I load lighter.  May as well get a shovel....

Thanks again for your help.
Pieter

-----Original Message-----
From: ROBERT HEMINGWAY [mailto:r hemingway verizon net]
Sent: Friday, June 07, 2002 9:50 PM
To: Pieter Litchfield
Subject: Re: (ET) e-15 eats reverse relays


If you're eating relays, it sounds like you're switching from forward to
reverse rapidly, while the motor is still drawing current.  Stop in neutral
first.  It draws more than normal current when it is still rolling in the
opposite direction  When the Electrak was produced and sold in the early
70's this was not a characteristic failure.  The drive motor is all
windings, so there is not really anything in the motor that I know of that
turns it into a generator, even when it's rolling down a hill.  I cannot
speak as an expert anymore (it's been thirty years since I was a Quality
Engineer at GE for the Electrak.)  The predominant failures were 1. Battery
failure 2.  Mower motor bearing failure 3. Front axle breaking due to 
faulty
castings 4.  Drive motor reversing under heavy load especially from the
tiller 5. Paint chalking (Paint was supposed to be acrylic but Egytian 
Paint
substituted alkyd paint.  GE paint formerly in Chelsea, MA confirmed that
Egyptian had falsified their paint test data.)

This information may not be helpful, but I throw it out as somewhat blurred
memory.  We did have a generally tough time with most of our dealers,
because they were gas engine people and did not have a good understanding 
of
the electrical characteristics of the tractors.  My function as Quality
Engineer was to design all of the factory testing including wiring and 
final
test, which was done with a dynamometer and digital gauges.  I was also in
charge of all of the inspectors.
Bob Hemingway
----- Original Message -----
From: Pieter Litchfield <plitch attglobal net>
To: Discussion list Electrac tractor <elec-trak cosmos phy tufts edu>
Sent: Friday, June 07, 2002 8:24 PM
Subject: (ET) e-15 eats reverse relays


> Gang:
>
> My e-15 w/bucket loader has a nasty habit of eating the reverse relay - 
> it
> welds or fries the contacts while in reverse, or when switching from
reverse
> to forward modes.  Over the past several years it has eaten 3 or 4.
>
> I am now using the improved Bill Gunn relay, and while definitely
stronger,
> the tractor's demon is stronger still.
>
> I had assumed that perhaps the motor of a rolling  tractor acts as a
> generator and that shifting too quickly from reverse to forward might
allow
> the motor to weld contacts (or something).  I do notice a spark when the
> rely breaks contacts with the reverse contacts if I shift it without the
> motor coming to a standstill, even with the tractor in neutral.  No spark
> seems to occur when the motor is completely stopped.  However, this could
> just be coincidental with something else - like a component that looses a
> charge over a short time.
>
> I do have the complete "homeowner's repair manual", but I ain't no
engineer,
> so I look at the pretty pictures of wires and remain more or less
clueless.
>
> I'll ask Bill when I order more relays, but does anyone else want to
venture
> a suggestion as to why I eat relays?
>
> Thanks!
>
>