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Re: (ET) GE Elec Trak



Guys,
  I received several email replies about details of the relay conversion
so here's a mass answer.....

- Replacing original finger relays
    24 volt DC relays can be used but you need to add a resistor because
they are connected to 36 volts on the tractor.  Relay contacts should be
DPDT and rated 10 amps.  The resistor you put in series with the coil
needs to be approximately 1/2 of the coil resistance (use 2 watt size).
   Here's an email from 2005 on this subject:
I replaced my dashboard relays with the following items. They are from
MCM InOne (electronics distributor)  in Ohio. The catalog is on-line.
relay 28-4950         $6 each  DPDT 10 amps
socket 28-4951     $7 each

The relays can be mounted in the sockets of course- they are small and
narrow, good fit. The relays also have upside-down mounting ears so you
can mount them "terminals up" and use the existing push--on connectors.
My connectors are weak and corroded so I used the sockets.
These relays are 24 volts 600 ohm coils. I used a 270 ohm/ 2 watt
resistor in series with each coil. They operate fine and do not get
nearly as hot as the old relays.

   Then, no more relay issues.  Potter & Brumfeld make similar relays
which are the ones I used.

- Battery Chargers
    Soneil chargers are mentioned and used quite a bit.  A while ago
someone described the Japlar-Schauer charger and I bought one and use it
with an SB-50 plug (small version of an electric fork lift plug for
quick disconnect available at forklift/Industrial stores) and it works
well for my tractors.  That way I don't haul the charger around either.
   Website is:
http://www.battery-chargers.com/chgrpic.htm

...Walt

-----Original Message-----
From: Konstanty, Walter (GE Energy Services) 
Sent: Friday, June 24, 2011 9:41 AM
To: David Roden (Akron OH USA); elec-trak cosmos phy tufts edu
Subject: Re: (ET) GE Elec Trak

Guys,
   28 years ago I removed the finger relays from my E-15 and put in 24
volt Potter Brumfeld plug in socket relays and have not touched the
control since.  At that time I cleaned and tightened the circuit board
contacts and any other suspicious connections.  It runs as good as new
with zero maintenance.  Added a "smart charger" since with SB-50 plug to
use on both ET's I have.  The E-20 was converted to a METI repower kit
using a GE programmable golf cart controller and while it doesn't regen
it provides flawless operation and smooth acceleration.  The original
finger relays were the biggest issue with the controllers - change them
out and it will run forever unless you want to modernize with a new
control.
   Keep em running !!

...Walt

-----Original Message-----
From: David Roden (Akron OH USA) [mailto:etpost drmm net]
Sent: Friday, June 24, 2011 12:39 AM
To: elec-trak cosmos phy tufts edu
Subject: Re: (ET) GE Elec Trak

Can't help you on the solar part, but I can tell you that I fitted an
Alltrax controller to my E15 a few years ago.  I would never go back to
the factory speed control.  The Alltrax is buttery-smooth; I can move
the 
tractor by centimeters.   (As a note, there are other transistor
controllers
that can provide the same service, it's just that this one is configured
for
ETs.)

It's also more reliable.  Folks will tell you that the big advantage of
the GE contactor controller is that it's easy to work on because it's so
straightforward.  They're right, and that's a good thing, because you'll
be 
working on it a fair bit, if my experience is any indication.   

On the other hand, once you get the Alltrax installed, it JUST WORKS.  

When I had the GE contactor controller, I was forever fixing something,
either a semiconductor on one of the cards or the burnt reversing relay
contacts.  The final straw came the blustery winter's day when I was
plowing and had to reverse the tractor by raising the hood, lowering the
relay panel, and pushing on the reverse relay.  

You can certainly rebuild or replace the various components of the GE
controller, and that will probably improve its reliability.  However,
IMO it's not worth working on.  If yours works, I'd say use it until it
doesn't, and then rip it out and put in something that wasn't developed
in the Apollo Space Program era.  

But as you'd expect there are plenty of opinions to the contrary here.
;-)



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