Uncouple Track through AIU

Be careful powering the uncoupler from the AIU.  The uncoupler may not be as momentary as a switch motor.  It may draw more current than the AIU can supply. 

Atlas ought to be able to tell you how much current the uncoupler draws.  If you have a good amp meter you can measure it.  Check the AIU manual for the current limits.  There may also be a pulse duration to be considered.

Jan

The AIU uses relays to emulate the action of your existing manual uncoupling activation button.  You can wire one of the AIU Accessory ports across the button so either method can activate the uncoupler section.  Here's an edited photo I hijacked from this thread:  https://ogrforum.com/t...coupling-track-guide

There's a somewhat lengthy discussion about using an AIU Accessory port for uncoupler sections here:

https://ogrforum.com/t...g-track-from-the-aiu

Basically, if you leave the uncoupler magnet activated and walk away or forget it is "on" it will overheat and undoubtedly melt something.  The spring-return-to-off for the supplied manual switch protects against this.  

For the AIU,  you should NOT use the "ON" button on the DCS Remote to activate the uncoupler Accessory.  This powers the uncoupler and leaves it on after you release the button until you subsequently press the "OFF" button on the remote.  Instead you should to use the remote's "ACT" button which only activates the uncoupler as long as the button is held down.

Thanks for the info.  Tomorrow I'll be giving it a shot.

I've done it both ways: using an accessory port and also using a switch port.

Both worked equally well, but I had more peace of mind using the switch port for reasons mentioned above.

- walt

To protect uncoupling coils, I have been using 1/2 amp hold, 1 amp trip resettable fuses in all my uncoupler feeds. Theory here is that the fuse definitely plans to trip on each uncouple operation, but the operation is complete before the fuse gets around to doing its thing. My uncouplers all feed from dedicated buses, so I only need one fuse per bus, but you can get resettable fuses for around 20 cents so the cost is not high even if you need a lot of them.

The ones I use trip in about 5 seconds with 14 volts to Fastrack couplers. I measured the uncoupling current once, seems like it was 3.5 amps or so. I also wired 14V bulbs across the fuses, the bulb lights when the fuse is in "tripped" mode. 

I am intrigued by Barry's idea about connecting the Atlas UCT to the SW AIU terminals, albeit for an very short activation. I thought of this option as well. I'd like to take advantage of the DCS System allowing me to avoid making a traditional control panel, and commit to the remote and iPhone/iPad options. I have enough unused SW slots on my multiple AIUs that I enjoy using for accessories. Barry, how would you wire WITHOUT using the momentary push button terminal included with the UCT?

BTW, downloaded the eBook version of Barry's WiFi Companion for portable reference on my iPad. Wonderful. Also purchased the soft cover hard copy, being an old fashioned tree-killing lover of printed reference material. Exceptional. Do I get frequent flyer credit? Ha! 

Thanks in advance.

Ron