wireing MTH crossing gates to track

You need a relay.

In layman's terms the MTH crossing gates have 2 input wires that tell it what to do.  Yellow wire tells gates to go down (and start flashing), White wire tells the gates to go up (and stop flashing when gates reach top).

The insulated rail method only provides one signal.  A relay converts this into two signals to drive Yellow and White.  That's what the ITAD does in the MTH diagram; there's a relay inside it that drives Yellow when a train is detected or drives White when train is gone.

There have been dozens of OGR threads written on this.  It's hard to point you to one since everyone seems to have a slightly different setup or requirement.  Do you have Accessory AC voltage from your train transformer or do you really need to run it off track voltage?  Are you running conventional or command control?

Hi Trussman,

Stan is correct.  To wire the MTH crossing gates to an insulated rail (your rail "A") you will need a relay that can power both the "UP" and "DOWN" circuits.  One option is to use a Z-Stuff DZ-1008A relay, which is available from many train retailers.  Here's a wiring diagram that shows you how to wire the MTH gates with a DZ-1008A to an insulated rail.

Link to a previous thread.   Pictures that show the (5) wire connections.  A NC/NO relay is required for proper operation, add another wire for track sensing to the relay.   Keep in mind there is a (SEARCH) feature, Blue bar beginning of this page.

Thanks for all your input.

What everyone's saying, I'll need the relay. I just can't wire direct to the track and not use the relay ?

You need a relay.

On my old layout, I used two different insulated tracks to raise and lower the gates.  I put one track a bit before  the crossing and connected the yellow wire to that insulated track.  When the engine reached this track, the gates would lower. Then, a little more than a normal FULL train length past the crossing, I put another insulated track but with the other outside rail insulated so as to serve as the 2nd switch. I connected the white wire to it which, once the engine reached it, would raise the gates.

Note, this only worked properly with trains going in one direction. 

@raising4daughters posted:

...

Note, this only worked properly with trains going in one direction.

If the triggering rail spanned both approaches to the crossing, wouldn't it work in both directions....assuming your layout is large enough to support a FULL train length on each side?

To your point, you do not want a situation where the Yellow and White wires are simultaneously triggered!  I have dissected the electronics of the MTH crossing gate and it does not take kindly to such a proposition. 

Above diagram illustrates another "concept" in isolated-rail triggering.  More than 1 isolated-sections can be tied together to create a single trigger wire to the gates.  In this case there are 2 sections for the gates-down (yellow) trigger and 2 sections for the gates-up (white) trigger.

The MTH crossing gates are kind of a special case because it will flash the alternating red lights whenever the gates are away from the upper-most position.  It will do this without a trigger on either input.  So in addition to the FULL train length requirement between down and up trigger sections, the trigger sections must be long enough so a passing train triggers the gates to go all the way down or return all the way up.  It only takes 2-3 seconds for the gates to change positions so this should not be a problem.

In both diagrams above just the 2 trigger wires (Yellow and White) are shown.  The other 3 wires are connected per instructions.

@stan2004 posted:

If the triggering rail spanned both approaches to the crossing, wouldn't it work in both directions....assuming your layout is large enough to support a FULL train length on each side?

To your point, you do not want a situation where the Yellow and White wires are simultaneously triggered!  I have dissected the electronics of the MTH crossing gate and it does not take kindly to such a proposition. 

Above diagram illustrates another "concept" in isolated-rail triggering.  More than 1 isolated-sections can be tied together to create a single trigger wire to the gates.  In this case there are 2 sections for the gates-down (yellow) trigger and 2 sections for the gates-up (white) trigger.

The MTH crossing gates are kind of a special case because it will flash the alternating red lights whenever the gates are away from the upper-most position.  It will do this without a trigger on either input.  So in addition to the FULL train length requirement between down and up trigger sections, the trigger sections must be long enough so a passing train triggers the gates to go all the way down or return all the way up.  It only takes 2-3 seconds for the gates to change positions so this should not be a problem.

In both diagrams above just the 2 trigger wires (Yellow and White) are shown.  The other 3 wires are connected per instructions.

Thanks Stan, this is what I was looking for.

As nice as the Railking crossing gates are, it's too bad they weren't built as a "fail-open" design. In other words power needed to close the gates, and when removed they return to open. This would make wiring much simpler and all you would need for a basic installation is an insulated outer rail for 2-3 feet either side of the crossing.

Does anyone know if there are any crossings made this way?

Rod

Lionel #252

What he said.  Solenoid spring-return mechanisms "fail-open."

To get the slow "Tortoise-like" gate motion I'd think you'd need a geared motor which means you need power to slowly/prototypically return the arm(s) to the open position.  I can't imagine any crossing gates with "battery-backup" or the like to provide several seconds of power to slowly raise the gates so that it returns to the open position if power lost!

Lionel Mainline crossing gates have three wires.  Red,Black, Yellow.   Yellow goes to insulated rail.   Red and Black to power.  Simple hookup.  

@Vinny26 posted:

Lionel Mainline crossing gates have three wires.  Red,Black, Yellow.   Yellow goes to insulated rail.   Red and Black to power.  Simple hookup.  

Not sure what version you have but the 6-14098 Mainline crossing gates that I have are a 5 wire device, and still need an external relay just like the Railking does. Yours must be newer.

Rod

Here we go again!

Same model/SKU but wiring depends on the version date.   3-wire (newer) and 5-wire (older).

If one has the older 5-wire version, you can convert it to 3-wire (insulated-rail) operation with a relay as discussed in this contemporaneous OGR thread.   Per the linked thread, the relay will set you back between $1 and ~$25 out-of-pocket depending on how much soldering, wiring, hair-pulling, etc. one can tolerate.

Stan,  yes the newer one.   Real easy to hookup.  No relay.   Thanks for showing the diagrams

How do they operate Vinny? Fairly realistic? Could you show us a video please?

Rod

This video shows a pair of the Railking 5-wire gates in operation. Nice slow action, fairly realistic, though a pain to wire. And noisy! These are activated by a set of two Z-1011 trackside sensors, and one Z-1050 block signal, all activating a Z-1008 relay. I had to get Dennis Zander to give me some help with a couple of blocker diodes in the wiring so the sensors would play well together.

Definitely a 3 wire device would be a whole lot easier to install.

Rod

I posted this video of the MTH 30-11012 gates in an earlier OGR thread.  This shows the effect of intermittent or interrupted Yellow and White triggers in the middle of a down-up cycle.  Specifically, as previously mentioned, once a cycle starts, the MTH gate arms hold their position and the flashers continue to operate in the absence of a Yellow or White trigger.  This behavior is key to using the no-relay method using the separated (by FULL train length) isolated-rail trigger section method.

Here you go.  Three wires Y

Thanks Vinny; that works quite well! And Super-O track, way too cool!

Rod