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Re: (ET) Update
Recalling your last post this is a spark producing, not just 'read on a
meter currentless leakage? If so; not normal to any GE/WH I have
worked on. But then again haven't worked on all models. Would suspect
design philosophy to follow all other EV practice that all voltage higher
than 12 (lights etc) be isolated from the chassis.
A place liable to insulation 'scrapeage' is the cable carring wires to
the right front of the rear batt compartment. A loose belt will hit it
and scrape insulation off that cable.
Also - any place where any wire or cable goes through a hole. some had
grommets but even though it looks OK there is eaten away inside exposing
cable scraping bare metal. Had that problem on my fullsize 120V PEV.
Grommet went away (though looked good) on the front- rear interconnect
and made my chassis hot to about 3/4 batt voltage. Evrything worked OK
except the voltmeter erratic.. And a tickle when I touched a battery
terminal. That 120 has no chassis connection, same as an Etrak. Found
that one easy enough as it was partial voltage available on only one
cable. But yours is full voltage.
A clue to location can be given by opening up the main switch seeing if
it's still there. Then see if it's there with main switch closed, key on
and key off. Brakeo n brake off, sea switch satisfied then off. (all
others should be 'on' when testing this way). BE SURE
that the tranny is in neutral or better yet, neutral with a rear wheel
jacked up when you do this.
BE CAREFUL wiggling through the chassis cables etc to see what happens.
A meter can lie here with a high resistance leak. If the meter reacts
the slightest bit when you wiggle cables suspect the point that you
wiggled or moved away from the chassis and insulate it, try again to
confirm. I would use an analog meter with good test clips not probes on
this cause a pointer is a lot more visible to quick intermittency than a
digital reading, and an analog meter draws a little current (20,000 ohms
per volt). If you got a 50V scale, use it.
If there's a meter reading and no spark, acid fume residue on the battery
will carbonize airborne crap and make a tiny sparkless but readable leak.
Rinse the batteries carefully with plenty of water making sure no hose
water gets into em. Water will exit through the compartment drain(and
rust) holes, no need to remove batts. Do not 'neutralize' with baking
soda as there is a good chance some will get in the cells no matter how
careful you are. Also, Alkaline water is as bad as acid water, if not
worse to make more rust. Don't retest it for a week until the
comparments are thoroughly dry.
Don't neglect the battery charger it's a tractor part too. To isolate it
for testing disconnect it both sides of it's output.
There's another way to find a chassis leak but I won't post it as it can
be quite damaging to the tractor when done by anyone not experienced in
big Emotor, gen, welder etc repairs.
Dave
Weymouth MA
On Mon, 7 Aug 2006 13:55:03 -0400 "Jerry Rhodes" <jerry38 alltel net>
writes:
> Well Jerry got his voice back down to some what normal, {{VBG}}...did
> take
> the EGT 120 out for a workout this morning..after fingering every
> wire on
> the frame no bad spots.. everything is tight and clean...so ran her
> in the
> yard pulling a couple hopper wagons into place for cleaning...
> worked fine
> just need to get the stopping down to a better art...now for the
> short of
> 36.9vdc to the frame...is this not right or normal for this
> tractor??
> back to work, later
>
> Jerry NWO
> ----- Original Message -----
> From: "David C Robie" <mycroftxx1 juno com>
> To: <rjkanary nauticom net>
> Cc: <jerry38 alltel net>; <elec-trak cosmos phy tufts edu>
> Sent: Monday, August 07, 2006 1:58 AM
> Subject: Re: (ET) Update
>
>
> > We called that 'dead short' stop 'motor plugging' and it's suppost
> to be
> > very bad juju for motors. But it's the way that GE stops the
> deck
> > blades pretty much instantly when it's contactor drops out. And
> it don't
> > hurt deck motors. I did it before retirement on some robotic
> items such
> > as gearmoters running an underwater arm with grab and 3 axes of
> motion
> > and it didn't hurt em. It only hurts Jerrys (ouch !). Just
> don't
> > stand up when you drive, guy.
> > Seriously, it could be of use to decelerate the tractor in
> higher
> > tranny gears as she would normally do in lower gears. Take out
> the short
> > (go ahead, ask 'short what?') but in it's place put in a kinda
> hefty low
> > value resistor such as an old electric iron turned on 'high or
> 'steam'.
> > This could be area of experimentation that could improve
> Etractordom, as
> > we all know how useless and fast wearing down that Peerless disc
> brake,
> > designed for a much lighter tractor is in high gear or even
> third.. Let
> > that back EMF instead of stopping her dead slow her down faster
> than just
> > an open circuit there would. To stop her in a high gear now we
> got to
> > 'stage down' thru the electrical speeds way ahead of her stop.
> This way
> > would make 'stop' have some (not ultimate, as per Jerry) 'power
> off'
> > braking action too.
> > This is not true regen, as true regen uses the back EMF to
> charge
> > the battery. Very little charge could come from a tractor but on
> a
> > fullsize road EV it can increase range a few percent and in city
> stop n
> > go driving saves a lot of wear on the brake linings of a heavier
> than
> > normal vehicle.
> > If it Twer me, would play with that a little bit. A lot of
> > inventions happened because someone did something wrong and good
> things
> > came out of it. Wasn't the telegraph invented that way? And Irish
> Spring
> > soap?
> >
> > Dave
> > Weymouth MA
> >
> >
> >
> >
> > On Sun, 6 Aug 2006 14:59:57 -0400 "RJ Kanary"
> <rjkanary nauticom net>
> > writes:
> >> Once again.....Permanent magnet motor ? You will have
> to
> >> reconfigure the armature contactors so that there is no longer a
> >> dead short across the armature when the contactors are not
> >> energized.When I was young and uneducated on such things, I used
> a
> >> set of armature reversing contactors from a large frame tractor
> on
> >> my E-10.
> >> {I found the clutching and gear shifting rather tedious
> >> maneuvering around obstacles on the lawn. }
> >> Did I get an education when I moved the directional
> switch
> >> to its neutral position !
> >> I never rectified that I just got used to it.My Dad
> >> OTOH,never DID get used to it. <VBG>
> >> ----- Original Message -----
> >> From: Jerry Rhodes
> >> To: Elec-trak Mail List
> >> Sent: Sunday, August 06, 2006 2:33 PM
> >> Subject: (ET) Update
> >>
> >>
> >> Afternoon all, lovely here in NW Ohio..sure beats 95 deg. Well
> got
> >> 2 things to bring up
> >>
> >> 1A.. Got the NI EGT 120 running..nice fwd/rev left/rite PTO
> >> works...BUT HOW DO U shut OFF the regen braking on the motor???
> >> after about 75' down the driveway I put her in neut and pulled
> >> myself off the hood back into the seat ...that puppy STOPs**NOW**
> >> man can we change that?? My E14 dosn't do that..
> >>
> >> 1B..went to clean her up, pulled the batty cable off ( neg
> >> frt/rear cable) an layed it up on the edge of the frt batty box
> and
> >> she danced around (small sparks) not good, for sure not
> good..read
> >> cable to frame/dash reading 24.8 vdc..not good..put cable on post
> >> ... no spark, cable off read post to cable 36.9 vdc ...so I have
> >> short to frame...need to check ALL wiring..any ideas to start?
> later
> >>
> >> 2. update on ET Swapfest/Show...later today
> >>
> >> Jerry NWO
> >>
> >>
> >>
> >
>
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> > -----
> >>
> >>
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