Re: (ET) E20 motor current sense connections

[Christopher Zach <czach computer org>]

Mine was overheating as well, however the reason seems to be my field 
weakening circuit on card 4 is not closing the FW relay properly. Thus 
FW is still availible even though the motor is loading up. Presto: Way 
more heat on that shunt.

For now I have been not using FW unless going down hill. I've got to fix 
this before spring. Regardless my tractor is buried in the red on the 
meter with the snowblower running, but that's not going thru the 
armature shunt.

Chris


steves wrote:
> I should listen to my own advice. Last week I mentioned checking the 
> connections to the motor current sense and I then I fell victim to it 
> myself. I was out plowing the 'big' snow of the season (about 6") when I 
> smelled hot electricals and smoke started coming up from under the hood. 
> Long and short of it it was loose connections between the top of the 
> copper strap used as the motor current sense and the threaded post that 
> holds it and conducts down to the wire connections.  Since this happened 
> mid-plow, I just took out the threaded rod and bolted the cables right 
> to the shunt. What a mess - insulation is melted back a inch or so on 
> the wires, the plastic (?) support is burnt, etc....
>
> Anyway - check those connections. The shunt was way too hot to touch 
> (burnt thru my favorite winter gloves - dang!) - I would think the shunt 
> should nevereven get  warm, right?
>
> - SteveS
> E20
>
>
>
>
>
>
>
> _______________________________________________
> Elec-trak mailing list
> Elec-trak cosmos phy tufts edu
> https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak