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RE: (ET) E20 lacking power



Thanks for all your replies. 

Based on Steve's suggestions I did some measurements
this evening. The following table shows the voltages 
I measured in the different speeds with the transmission
in neutral. I later measured under load and the only 
major difference was the armature voltage that caved 
in on heavy loads mainly in speeds 1-3, which was 
expected.

Speed    Armature     Field    Battery
1         29.8        34.5      37.5
2         30.6        34.4      37.3
3         31.6        34.4      37.3
4         33.6        33.4      37.0
5         35.5        33.2      37.0
6         35.5        11.7      36.7
7         34.7         8.1      36.7
8         34.4         5.5      36.5

I was puzzling why the field current is lower
than the battery. The voltage drop from the 
diodes shouldn't be that much (0.7V, right?). 
So maybe I should revisit that circuit to make
sure I provide a high enough voltage to the field.  

The performance of the tractor while driving it around
seemed a bit better than yesterday. Maybe the field
connector wasn't seated right and had a high resistance.
Running in D2 is now mostly in the yellow area
except when going up inclines. 

Markus

> > Also poor motor performance and large currents is usually 
> associated 
> > with a weak (or missing) field. You may want to hook up the 
> voltmeter 
> > across the field terminals and check that it's 36V when in 
> > cruise mode - 
> > actually I guess anything below the field weakening setting 
> > should be 36V?.
> > 
> 
> These are good points. Too low a field could really be the problem and
> I haven't measured the field voltage after I fixed the 
> diodes, so I think
> this is a good thing to check. 
> 
> Thanks
> 
> Markus
> 
> > 
> > SteveS
> > E20
> > 
> > 
> > 
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> > 
> 
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