My question arose from my previous question about a wind direction measuring circuit.
Please have a look at the manual: http://www.fondriest.com/pdf/rm_young_05103_manual.pdf
And here is the figures about my questions:


In Figure A, the potentiometer is used to output voltage proportional to the wind vane rotation angle.

In Figure B, the potentiometer comes to an end at point 1 and causes a short between the lines WHT(wind excitation voltage) and GRN(wind direction signal). But in theory current flows from + to ground. Do you think there is a path for current to flow in Figure B?

In Figure C, it seems like the situation is safe. Although the lines GRN and BLK are shorted at point 2, there is no potential difference and no current flows. Is that right?

My real confusion is about D6 and D7 the transzorb diodes(zener clampers?). I couldn’t really figure out in which circumstances they function and what happens in the absence of them. Why do we really need them? 

In the manual it states: “To prevent false readings, signal conditioning electronics should clamp the signal to excitation or reference level when this occurs.” Do you think one needs an extra circuitry at the output?


Question: What preposition should be used in "Moving something __ M meters"?
Answer: They are all fine, also:


  move something over N meters.