Basic electricity 101 help please?

[Onrman]

Okay guys I require some basic help here. I have just recently returned to the hobby and I wanted to update a number of sidings and such on my large DC layout. Here is my problem - I used Atlas Selectors to control the power feeds to each of my many sidings. Each siding has two plastic rail joiners at the start of each switch feed to the siding. Power leads are then applied at railjoiners within the limits of the siding. All outside joiners that are powered go to the same collection point. I then designated the other powered jpiners to the separate feed from the selector. The transformer sends power to the selector and the collected negative rail joiners. Everything was working fine until I  noticed a definite loss of power on one side of the layout. I discovered that I had reversed the power leads on the opposite side of the room When I corrected the issue I dsicovered that all sidings are operational no matter what the selctor states. Should I add my second MRC transformer to the other main power connection to the Atlas Selector?

[challenger3980]

I find DPDT (Double Pole Double Throw) Toggle Switches to be much less confusing, just make sure that you use center OFF switches.

                                                        Doug

[xdford]

How did you discover that you "lost power and needed to reverse the wires?  Did the train go the opposite to that which was intended and the rest of the layout in that section alone? If you place it in the middel of the isolated section does it travel the reverse way?

I don't know Atlas selectors at all having never seen them here in Australia. I assume they are virtually an on/off switch. If you "reversed the leads" did you do this at the switch or the track section? Does reversing the leads to what they were restore your situation?

I would suggest sight unseen that you have somehow fed back power to the live side of all switches, maybe through a switch breaking down?

Feel free to contact off list [e-mail]  or my website www.xdford.digitalzones.com

Regards

Trevor

[dinwitty]

you may have a "short" but not the shorting kind.

You will have to go over your work, designate a "power" feed and a "ground" feed, then designate your "alternate" feed on each of your selectors. or "cab1" and "cab2" on your power feeds, check all your wire routes, and your track feeding and insulation. A passing siding will need 2 breaks on the pass and you will have to carry thru the "ground" line to one rail, the other rail will be your selector switch. This all depends how you want to wire and work the layout, so how you wire it will depend how you work the layout. There are standard ways, but then there are the creative ways. Study it again and then maybe take it again from the top, okay?..."k" 

[IRONROOSTER]

Do not connect the second transformer.   Selectors switch between two power sources (IIRC with center off), without the second transformer the selectors wshould turn power off on each siding in the B setting (assuming the current wiring is from the A side).  If they don't do that then you have reverse wired one siding (or not correctly blocked the siding) which is completing a circuit back to your selectors on the B setting - this allows all the tracks to be powered on the B setting.  Disconnect the siding that you reversed and see if this clears up the problem.  If not you need to disconnect all your power blocks and then reconnect them one at a time until you discover where the problem is.  The one with the problem is wired incorrectly.

Hope this helps

Enjoy

Paul 

[Phoebe Vet]

I think you need to be more specific about which Atlas switches you are using.

The one Atlas calls "selector" (Green Switches) is a single pole double throw set of 4 switches.

The one Atlas calls "Connector" (Yellow Switches) appears at a glance to be double pole single throw, but is actually single pole single throw set of 3 switches.  One pole is not switched.

The one Atlas calls "controller" (red and green switches) has two double pole double throw and one polarity reversing switches.  It is used to switch one track between two power sources.

It will help you picture your circuits better if you decide which rail is 'A" and which rail is "B", assign a color to each and use that color code consistently everywhere on your layout.  If you do that you can look at your switches and any wrong rail wiring will be obvious.  The wire on the switch will be the wrong color.

Ironrooster's suggestion should always be your basic trouble shooting plan.  Disconnect everything.  Then reconnect one item and test. Connect one more item and test.  Repeat until the problem occurs.  That one is the problem.

[wm3798]

Psst:  Install DCC, sell off all that copper, and use the proceeds to buy a convertible.

Lee 

[Texas Zepher]

Everything was working fine until I  noticed a definite loss of power on one side of the layout. I discovered that I had reversed the power leads on the opposite side of the room When I corrected the issue I dsicovered that all sidings are operational no matter what the selctor states.

Back everything off to the point where everything was working fine, and start forward from there again.  This is why all the books say to do one wire at a time and test between each.   I am guessing that when you corrected the "opposite" side somehow you've got one wire jumping between what were the two "commons".  It still surprises me that "ALL" sidings are operational.  I would have expected SOME but not all, especially since you have two plastic feeders on each siding.  A common rail system only needs on insulated joiner on each siding.   And then finally are you certain there is not a reversing loop involved in this somehow.  An unrecognized reversing loop can easily cause one to flip the common to the wrong rail.   Is your inside rail or outside rail the common?

Should I add my second MRC transformer to the other main power connection to the Atlas Selector?

No, that would only complicate things and possibly start melting things down.  Find the real problem first.  Fix it and then add the second power supply.