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Re: (ET) What was that crash?
- Subject: Re: (ET) What was that crash?
- From: "David Roden (Akron OH USA)" <roden ald net>
- Date: Sat, 8 Jun 2002 13:48:20 -0400
- In-reply-to: <115.12a56337.2a33868f@aol.com>
- Sender: owner-elec-trak cosmos phy tufts edu
I always open the main disconnect when the tractor is parked. I can do
this
since I charge with three external 12v chargers instead of the onboard
charger.
I haven't looked into it, but it seems to me it shouldn't be all that
tough
to rewire the onboard charger so it doesn't go through the disconnect.
That said, it's hard for me to understand how the tractor could start
itself. For the L1 to pull in, you have to have the key on, the seat
switch
down, the brake up (doesn't apply to this one?), and the speed lever
advanced. That's 3-4 switches that would have to fail. Doesn't seem
likely. Is the seat switch definitely working? Are you sure you had the
key off? I've accidentally left mine on a few times.
Barring such unlikely situations, the contactor would have to be at fault
here. Typical contactor failure modes are that the coil opens and it
won't
pull in, or the contacts weld and it won't shut down. I have never heard
of
a contactor closing on its own. The only reason I can think of would be a
badly weakened return spring.
In this case, it's a safety issue. I wouldn't fool with it -- change the
contactor, even if it seems OK now. Perhaps even add a redundant one
somewhere.
David Roden - Akron, Ohio, USA
1991 Solectria Force 144vac
1991 Ford Escort Green/EV 128vdc
1970 GE Elec-trak E15 36vdc
1974 Avco New Idea 36vdc
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