Re: (ET) E-12 electrical problem

[Chris Zach <czach computer org>]

No reverse is probably a blown diode. Check the archives; I went thru 
this whole thing with someone else. Basically there are two diodes that 
provide field power to the field from the quad contactors (in your case, 
dual) regardless of the polarity on the armature.

When one blows up, field doesn't come up, armature gets 100% current and 
hot as all get out. Replace with >5amp diodes from Radio Shuck.

E12: Simple as pie.

Chris


willaim att net wrote:

> I get no forward movement with the speed control. The speed control 
> microswitches check out OK. I can see no loose wires  or signs of 
> overheating in the control panel. I did notice  that the center terminal 
> on the charger was strangely very warm.
> After getting it into my garage, I found that re-engaging the power 
> disconnect causes the traction motor to go in reverse, with or without the 
> key switch being on and with the speed control in neutral.
> I have a manual, but I don't know how correct the page 4-4 schematic is 
> because some previous owner apparently made the conversion of double to 
> single contactors. The model number is 26AE12HA. Anyone out there ever 
> have this problem or have a clue to advise me?
>
> Bill Alburty in KC 
>
> _______________________________________________
> Elec-trak mailing list
> Elec-trak cosmos phy tufts edu
> https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak