Re: (ET) Interesting, that's what eats E15 relays....

["Clean Power Supply" <cleanpower att net>]

 Chris,
 Learning by doing really does work! You've pretty well figured it out. If 
you put a new varistor (MOV) in good electrical connection across the 
field it should take care of most of the sparks.
 Harold Z.
On May 10, 2011 at 11:17pm -0400, you wrote:
>Interesting evening. I put a hand-wired fuse holder in for the control
>fuse, fired up the tractor, and it still works normally. Which is good.
>
>However since it was dark I noticed a little flash from under the dash.
>Opened the front panel so I could watch the relays and went from forward
>3 to zero. Nothing. Then I went into reverse. Nothing, FR relay clicked.
>Then I went into reverse, nothing. Then I went back into neutral and
>moved the lever over.
>
>*bang* flash in the relay box. And it suddenly hit me:
>
>What is happening is that in going from forward to reverse even when not
>going *into* reverse is that the FR relay is changing state. And if
>there is a residual current in the field from the armature spinning down
>it's going to flash the relay when it happens.
>
>I'll look into this more tomorrow, but I am wondering if the problem is
>not just going from forward to reverse while the motor is spinning, but
>going from forward or reverse to neutral *and moving the lever in the
>left/right direction* that causes an arc.
>
>If so that's going to be more complicated to fix. But it would explain
>why these relays fuse themselves with such aplomb, it's human nature to
>get yourself ready to go in the direction you want to go.
>
>Interesting.
>
>C
>
>_______________________________________________
>Elec-trak mailing list
>Elec-trak cosmos phy tufts edu
>https://cosmos.phy.tufts.edu/mailman/listinfo.cgi/elec-trak

------------------------------------------------------------------
Find out how easy email really is -- without a computer! Visit
www.landel.com or send email to getmailbuginfo landel com
------------------------------------------------------------------