Polarity reversal on line

[OLVtelephoneman]

We have a Partner system, but this question is about a fax line that bypasses the switch and is directly connected. When wired "correctly", i.e., a circuit test unit says the line is OK, phones and fax do not work right. But when reverse wired, i.e., circuit testers says line's polarity is reversed, everything is fine. Since there are only 2 wires involved, can someone enlighten me as to what is going on? The circuit tester is known to be working, at least working as it always has. Thank you!

 

[skip555]

if it works why worry about it ?

(its obviously polarity sensitive )

 

[Dexman]

I agree with Skip. If the device works properly, I wouldn't lose sleep over it.

The only thing I can think of is that the line cord from the wall jack to the fax machine wasn't terminated properly.

The pairs are supposed to be flipped so, on one end, you might have T|R and on the other end you would have R|T.

 

[skip555]

or the polarity was reversed internally when the item was assembled