Polarity of EZ Track terminal Track

[amnmann]

Is there any way to tell which contact on the side of the terminal track segment is attached to whcih rail. I am going to set up sub-districts for DC and DCC use and before attaching to the power bus I need to figure out a way to know exactly which contact affects which track on the terminal track piece.

Thanks,

[THB-DAVE]

Three was to check for that and its not Polarity, you are simply checking continuity. Use an ohm meter or a simple 12 volt light to check for current or just old fashion trial and error.

Dave

[prebres]

[Yampa Bob]

The contacts on the side of the terminal are not marked plus or minus for a reason, it doesn't make any difference.

Unless you are adding reverse loops just put it all together and separate your blocks with switches.  To check for shorts you might want to read this:

http://www.bachmanntrains.com/home-usa/board/index.php/topic,4952.0.html

The right rail is positive for forward running in DC mode. You don't even need a voltmeter to check this, put a DC locomotive on the track and set the controller switch to "forward".  If the loco moves forward, then the right rail is positive, if it moves backward reverse the connections.  It's called the "Right Rail Rule".

To maintain correct polarity while wiring blocks/switches, use red wire for positive, black wire for negative.

[amnmann]

  Thanks to you all. I think I got it.

Have a great day

[Yampa Bob]

Now that you "got it", I'll throw in a clinker that may confuse you now, but if you understand the principle you will not be more confused later. If you already know this, then please consider it a reinforcement for the right rail rule in your mind. 

Notice the EZ track power plug is not polarized, it can be plugged in either way. Let's say you want to run your loco counter-clockwise on a simple oval, with DC power to the track.  As mentioned, place a DC (or DC compatible DCC) loco on the track facing to the right, place the direction switch to "forward", insert the power plug the way that makes the loco move forward.  So far so good.

If you pick up the loco, turn it around, and set it on the track for clockwise running, the loco will now run backward even though the direction switch is set to "forward".  Why?  Because the right rail as viewed from the engineer's perspective is no longer positive.

So you have to turn the power plug over so the "forward" switch means forward.

When you make the switch to DCC power, if the forward light is lit, the train goes forward regardless of orientation on the track.

Good luck

[Jim Banner]

When you make the switch to DCC power, if the forward light is lit, the train goes forward regardless of orientation on the track.

This is true as far as it goes, but ignores the fact that with multiple blocks, you still have to worry about polarity with dc and phase with DCC.  If the phase/polarity is inconsistent from block to block then a short will occur when a locomotive crosses from one block to the next.

The easiest way to connect up multiple isolated blocks (i.e. blocks separated from other blocks by gaps in both rails) is to use one connection per block.  Start connecting up by plugging in two adjacent blocks.  If the power pack or command station or the block circuit breaker shorts when a locomotive crosses the gaps, then reverse one plug.  The two block should now be in phase (same polarity.)  Now plug in the next block.  If a short occurs when crossing over into this new block, reverse just the last plug.  Keep on doing this until all blocks are plugged in and working.  If you reach a point where reversing the last plug causes a short at the other end of the block, you have a return loop.

If your layout is large enough that you need multiple feeds in each block, then once you have one feed working in each block you can go ahead and connect up the other feeds in the blocks, one feed at a time.  If a short occurs (you don't need the locomotive for testing when the feeds are in the same block) then reverse just the last plug.

Note that this approach works even if the blocks are organized into sub districts or if the sub districts are divided into blocks.  This is sometimes done for easier trouble shooting.