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Can a block section be powered by a different transformer?

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Can a block section be powered by a different transformer?
Posted by Petery2 on Friday, February 1, 2019 12:44 PM

I'm planning a new fastrack layout that consists of two loops connected to each other and running of the same transformer. I would like to have a rail yard area that is connected to my outer loop but powered by a different transformer so I can use the loops and move trains around the yard at the same time. If I use a block section can I run a train over it or would it cause a problem when the train crosses over and is getting power from two different transformers.

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Posted by ADCX Rob on Friday, February 1, 2019 1:27 PM

This Tutorial will tell you why & how to phase your transformers, as many as you want, for an expanding layout.

Rob

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Posted by Petery2 on Friday, February 1, 2019 1:39 PM
Thank you
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Posted by lionelsoni on Friday, February 1, 2019 2:33 PM

Unless you can be sure that you can set the two transformers' outputs to match in polarity, waveform, and voltage, it would cause a problem.  Just matching polarity ("phasing") is not enough.  And, if you are crossing between two outputs from the same transformer, the electrical fault that a mismatch can cause will not trip the circuit breaker of many transformer types.

A safe way to do what you want is to power each block through an SPDT switch that selects between two sources, whether from the same or different transformers.  Then, before crossing the block boundary, assign both blocks to the same source.  Notice that this also allows you to create more blocks than you have sources, which can be handy when moving trains between loops.

If you use center-off switches, you can switch blocks off completely.

There is no need to match sources used to power most accessories, whether in polarity, waveform (for example, AC and DC), and voltage.  In fact, there are good reasons to have AC accessory voltages out of phase with the track.

Bob Nelson

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Posted by Petery2 on Friday, February 1, 2019 4:11 PM

Just to make sure I understand what your saying, get an SPDT that can switch between transformer 1 &2. Power the the block with the transformer its already on move the engine fully on to the blocked section then stop it and change the SPDT to the other transformer. Then I can run the on one and the block on the other then just do the same process to bring it back onto the loop.

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Posted by Penny Trains on Friday, February 1, 2019 6:53 PM

Welcome aboard!

Trains, trains, wonderful trains.  The more you get, the more you toot!  Big Smile

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Posted by JoeDilly on Friday, February 1, 2019 7:45 PM

Hi, Here is an article from the CTT web site that might help. Near the bottom is a diagram of how to use the toggle switches that Bob mentioned. 

http://ctt.trains.com/how-to/restoration-repair/2018/11/handbook-of-layout-wiring

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Posted by ADCX Rob on Friday, February 1, 2019 11:06 PM

CLICKABLE LINK to transformer cautions.

Rob

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Posted by Petery2 on Saturday, February 2, 2019 1:40 AM

Thanks everyone for the info. To make sure I understand correctly. I would wire the block to switch between transformers through a SPDT and be able to run the loop on one and yard on the other but before crossing the block section switch the SPDT so that both run of the same transformer then once the train is clear I can switch it back do there separate.

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Posted by lionelsoni on Saturday, February 2, 2019 8:15 PM

I think you've got it.

Bob Nelson

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