Where to place insulators?

Discussion in 'FAQs' started by Grotto, Sep 26, 2006.

  1. Grotto

    Grotto Member

    I am still working on creating version of Atlas N4 track plan, but now that I am actually doing the wiring I require some help.

    In order to creat the blocks, would it be prudent to place the insulators opposite the + terminal connectors are located? The only place where this would not work would be at the siding, and I am guessing that the insulator would go at the enterance to the siding just after the switch. This turned out to be more difficult that I realized.

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  2. steamhead

    steamhead Active Member


    I believe you need to insulate both rails at your three crossovers (right between the turnouts), and both legs of the blind sidings, although here you only need to insulate one rail. I presume you'll be using two packs (or DCC) to have at least two trains running at the same time.
    Hope this helps.

    Gus (LC&P).
  3. Russ Bellinis

    Russ Bellinis Active Member

    You can use one insulator on the crossover going from the inside oval to the stub sidings, you will need to insulate both tracks on the other two crossovers. A couple of other things to remember is to make sure that when you use one insulator to wire what we call common rail, the same rail needs to be the common rail all the way around the railroad. The other thing that is a good idea is to put a locomotive on the track, and hook up a throttle. Install the insulators before wiring the layout. Then as you wire the layout, run the locomotive after you install each wire. That way if you do something wrong and create a short, it is easier to find it, since it will always be the last wire you installed that created the short circuit.
  4. 60103

    60103 Pooh Bah

    Grotto: two small questions:
    Do you plan to use DC or DCC?
    How many trains do you expect to have on the layout at the same time?
    For DCC, you may not need any insulated joints at all.
    For DC, you probably need insulation at the crossovers. You may also need to insulate some more sections to hold trains -- possibly each of the curves could be a separate section. Then you wire them up so that they can be switched between the power packs or shut down.
    Trace out some operations on the plan and see how you would do things like change from one oval to the other.
  5. Grotto

    Grotto Member

    I really just plan to go DC.
    Part of the problem is that the Atlas book that I took this design from had many errors, all the way down to the quantities of parts required. This has been confirmed by the good and helpful people at Atlas customer service.

    I am using all Atlas track which I beleive has insulated switches. Right now I am just tempted to put the insulators half way between one + and the next +.
  6. Russ Bellinis

    Russ Bellinis Active Member

    The only places that it is critical to insulate both tracks are the two crossovers that run between the inner and outer loop. If you try to run two trains on two separate throttles at the same time in opposite directions without insulating both rails between between the two loops, you have a good chance of damaging one or both throttles. The Atlas switches have insulated frogs, but the switches are not insulated. The rails are "hot" all the way through except right at the frog.
  7. Grotto

    Grotto Member

    So does this mean that I have to place insulators at eaither side of the switch on the - rail?
  8. 60103

    60103 Pooh Bah

    You have a choice. You have another thread asking about common rail. If you choose common rail wiring, you only need to put insulators in the other rail. Then you need to run a wire to each separate section from your control panel.
    Without common rail, you insulate both rails and run 2 wires to each section.
    With the Atlas pre-made switches, they give you an effective common rail since the one side is tied together.
    Can you get a look at the Atlas wiring book? it may answer your questions.
  9. pgandw

    pgandw Active Member

    Here is my suggested gapping/insulated rail joiners for the electrical blocks.

    View attachment 30289

    Because common rail was desired, I show the gaps on the inner rail only. You could choose the outer outer rail instead.

    Why 4 blocks in each loop? Because you always need an unoccuppied block for a train to move into. If you have less, one train will be constantly stopping, waiting for the other train to clear the block in front.

    The normal 1st approach is to have a separate power pack attached to each loop. But this gets very ugly when a train tries to switch from one loop to the other. It's almost impossible to exactly match settings on the power packs for the train to switch from one to the other. Even if you do, when the train wheels are spanning the insulated rail joiner or gap, you have both power packs feeding the same train. The goal of block wiring is to make it possible for the same power pack to control the same train, no matter where it goes on the layout.

    Unless you are just watching them run independently on separate loops, running 2 trains with 2 operators on a layout this size is going to be an exercise in block toggle flipping. This is when DCC might well be worth the $200 investment (starter system plus 2nd throttle). In DCC, the throttles talk directly to the selected decoder inside the locomotive, you don't need blocks (or need to flip block togges). Two wires from the command station to the track and decoders in your locomotives are all the wiring you need to get started.

    My last comment is that I personally would find this layout as drawn quite boring quite quickly. At the least, I would add some more spurs and switching opportunities. But then my wife tells me I'm a cranky old guy too. :)

    my thoughts, your choices

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  10. Grotto

    Grotto Member

    I thought that with Atlas switches that insulated conectors wern't required. I'm sure that's what the salesman in the store said. I even showed him the book. I would love to be able to understand why they are required.
  11. Russ Bellinis

    Russ Bellinis Active Member

    The salesman is wrong. The Atlas switches are not insulated. The frogs are insulated, but the rails are hot all the way through the turnout. An easy way to test it is to put 12 volts dc to the points end of the switch, and then check voltage at both the straight and the diverging route. If your turnout is really insulated you won't get power out of it in either direction. When you check it you will get power out of both directions.
  12. 60103

    60103 Pooh Bah

    Grotto: the insulated joiners are not required to prevent shorts. However, you do need them to separate the power packs for multiple train running.
    Not sure exactly how the N gauge switches are arranged -- HO Snap switches have all the rails live and without insulated joiners your whole layout would be a single block.
    If you used all-rail switches, e.g. Peco electrofrog, having a switch in a loop can cause a short if it's set for the siding. That's where insulated joiners are required.

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