reply to mactalla
Re: [DSL] Dry loop installation: demarc box not connected? Yes... This is correct... If you accidentally cross the polarities, it will *NOT* damage any equipment or cause any effects that cannot be corrected easily. In particular, see the reference to the colour codes that I've shown in the little diagrams.
It's actually quite simple when it comes down to it. Electrically speaking, crossing the polarity isn't the end of the world. Also, if you're worried about getting "zapped" by the lines when you're working on them from inside the house, there's a little cheater tool that works on any Bell line from any area code. The two key numbers are:
519-958-2580 -- Telephone # Check
519-958-1166 -- Voltage Drop
These are numbers that Bell does NOT want their customers to have. You can substitute the area code within Ontario or Québec other than 807, 226, 647, 289, and the "new" area codes for larger metropolitan areas like Montréal. That being said though, you can still use the original code, so if for example the phone number assigned to the dry "Dry Gas" line is a 647 area code, you can use 416 instead.
In particular the Voltage Drop number is the key because this will cut the electrical voltage on the line for 3 or 5 minutes, which gives you as the "tech" the time to run certain line tests, or otherwise make some wiring changes easier.