Re: (ET) E-20 Controller failures.

["Steve Richardson" <scr echoweb net>]

Hi Chris,

The problem appears to be not being able to detecting a "field open"
condition.  The software regulates the field current based on the armature
current, trying to keep the field in the safe operating area of the motor.
That works great, but it did not account for a broken wire or 
miss-connected
wire.  Now we are modifying the software to check for an open field
condition.  It already has current limiting so that takes care of a shorted
condition.  I think Damon is also adding a cross current check between the
armature and field.  In other words it will always check both to insure 
they
are within the safe operating area.  He's not quit done yet so I won't be
able to give you all the facts until he tells me.

Thank you for your feedback we do appreciate input from you guys !

Steve

----- Original Message -----
From: "Christopher Meier" <mr23 mn rr com>
To: "Steve Richardson" <scr echoweb net>
Cc: <elec-trak cosmos phy tufts edu>
Sent: Tuesday, April 20, 2004 5:23 PM
Subject: Re: (ET) E-20 Controller failures.


> Steve, can you share with us all the conditions that are tested by the
> controller?
> I'd like to see if any of us can spot something else that is missing.  
> I'm
a
> little
> concerned that the controller (until this mod) wouldn't have detected a
> break
> in a field wire.
>
> ----- Original Message -----
> From: "Steve Richardson" <scr echoweb net>
> To: "Tom G" <wavetech superlink net>
> Cc: "elec trak" <elec-trak cosmos phy tufts edu>
> Sent: Monday, April 19, 2004 8:23 PM
> Subject: Re: (ET) E-20 Controller failures.
>
>
> > Hi Tom,
> >
> > Since I issued the warning about the E-20 field we have learned that 
> > one
> of
> > the failures was on a E-15.  The E-20 failure was caused by the field
not
> > being connected.  This suprised us so we are modifying the field 
> > control
> > part of the program to deal with a "Open Field" condition.
> >
> > The new code will be available on our web site as soon as we get it
> > completed.
> > I don't know when that will be at the moment.
> >
> > Thanks tom..
> >
> > Steve
> >
> > ----- Original Message -----
> > From: "Tom G" <wavetech superlink net>
> > To: "Steve Richardson" <scr echoweb net>
> > Sent: Monday, April 19, 2004 3:26 PM
> > Subject: Re: (ET) E-20 Controller failures.
> >
> >
> > > Does the shorting of the field controll wires cause the problem with
the
> > > controller?
> > > If so, would a fuse in line help from destroying the controller if 
> > > for
> > some
> > > reason the field windings in the motor short out?
> > >
> > > tom
> > >
> > > At 01:43 PM 4/18/2004 -0700, you wrote:
> > > >Hello Everyone,
> > > >
> > > >Those customers of Alltrax who bought their controller for the E-20
> > > >Elec-Trak please do not run them !
> > > >
> > > >We have had what appears to be two failures of E-20 controllers that
> have
> > to
> > > >do with the field circuit.  Until we can resolve these failures it's
> not
> > > >wise to run them !!
> > > >
> > > >We suspect the wrong wires coming out of the motor are being
connected
> to
> > > >the field connections on the controller.  The E-15 has two spade 
> > > >lugs
> on
> > the
> > > >side of the motor for the field winding.  The E-20 has four wires
> coming
> > out
> > > >of the side of the motor, two are for the field winding and two are
for
> > the
> > > >internal thermal switch.
> > > >
> > > >Looking at the E-20 Schematic there is a connector called "P6" that
> > connects
> > > >these four wires to the wiring harness.  The field winding is
connected
> > to
> > > >pins 1 and 2 of P6 and the wires coming out of the connector are
> labeled
> > #62
> > > >for pin 1 and # 36 for pin 2.  These are the wires that should be
> > connected
> > > >to the controller's field terminals.
> > > >MAKE SURE THESE WIRES REALLY GO TO THE FIELD WINDING.
> > > >The field winding has a resistance of about 12 ohms.
> > > >Pins 3 and 4 of P6 come out of the connector as wire numbers 5 for
pin
> 3
> > and
> > > >number 25 for pin 4.  These wires are for the internal thermal 
> > > >switch
> and
> > > >should read as a short if the switch is a normally closed and should
> read
> > as
> > > >a infinity if the switch is normally open.
> > > >
> > > >If any E-20 customer needs a E-20 schematic I have scanned it in my
> > computer
> > > >as a Paint drawing and I will send it to you.   And yes we will have
it
> > on
> > > >our web site soon.  Using paint you can modify the drawing later
after
> > you
> > > >complete your installation and everything works.
> > > >
> > > >We are sorry for the inconvenience we may have caused some of our
> > customers,
> > > >but we feel it's better to bring it out now and deal with the 
> > > >problem
> > right
> > > >away to keep others from having the disappointment and extra work of
> > > >reinstalling another controller.
> > > >
> > > >Any questions please call me at Alltrax, 541-476-3565 or e-mail me 
> > > >at
> > home
> > > >at scr echoweb net.
> > > >
> > > >Thank You
> > > >
> > > >Steve
> > > >Alltrax Inc.
> > > >
> > > >
> > > >
> > > >_______________________________________________
> > > >Elec-trak mailing list
> > > >Elec-trak cosmos phy tufts edu
> > > >https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
> > > >
> > > >
> > >
> >
> >
> > _______________________________________________
> > Elec-trak mailing list
> > Elec-trak cosmos phy tufts edu
> > https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
>
>