help with breaker

It is completely dependent on the equipment you are running at the time.

You might want to use ammeters to watch your power consumption for a while and then choose breaker values.

Breakers are meant to protect the transformer when there is a dead short from the tracks; a derailment or other problem. The rating of the breaker should match the possible amperage delivered from the posts that you use on the transformer.

When the breaker trips, power is cut off to the tracks. That's also good for the trains when there is a derailment.

When I was a kid running conventional trains around the track, my father always told us to turn off the power to the track as soon as we noticed a problem. Those trains still run today.

TVS on the other hand is a way to protect the trains from voltage spikes caused during a derailment or other sparking activity. These devices generally detect the spike and throw the overvoltage down the other side of the power circuit (to ground). For AC power, that changes many times a second.

Both fuses and TVS should be part of any modern setup.

I have always found this video interesting, shows how to size add on breakers for your trains. As I recall the guy doing the tests is also an EE. 

This link might help! My apologies for forgetting it the first time... getting old and forgetful!

RTR12: Tom, what video?

Consolidated Leo posted:

Breakers are meant to protect the transformer when there is a dead short from the tracks; a derailment or other problem. The rating of the breaker should match the possible amperage delivered from the posts that you use on the transformer.

When the breaker trips, power is cut off to the tracks. That's also good for the trains when there is a derailment.

When I was a kid running conventional trains around the track, my father always told us to turn off the power to the track as soon as we noticed a problem. Those trains still run today.

TVS on the other hand is a way to protect the trains from voltage spikes caused during a derailment or other sparking activity. These devices generally detect the spike and throw the overvoltage down the other side of the power circuit (to ground). For AC power, that changes many times a second.

Both fuses and TVS should be part of any modern setup.

Thanks.  I understand the difference in the purpose and function of TVS (protect boards / electronics in loco) versus breakers or fuses.  I'm really just looking for feedback from those that still use  postwar ZWs or KWs and use an in line breaker and run postwar locos and traditional size modern locos with non-led passenger cars and which rated breakers they are using.   Just curious what others use if they use a reset breaker with  the postwar transformer.   I guess I was just polling for tendencies or opinions.

Thanks and cheers  

I use 10 amp fast blow fuses on all my transformers, both old and new.  They only blow when they should.

Hi all, when installing an inline fuse or breaker is it best practice to put it in the hot side or the U side of the transformer to track wiring?

Consolidated Leo posted:

RTR12: Tom, what video?

I'm going to go out on limb and guess he means this video.

https://www.youtube.com/watch?v=aVeCPeeeRNk

Place it on the "hot" line.  

bostonpete posted:

Consolidated Leo posted:

RTR12: Tom, what video?

I'm going to go out on limb and guess he means this video.

https://www.youtube.com/watch?v=aVeCPeeeRNk

Good call on the video, Pete! As was demonstrated, the amperage of the breaker depends on the load from the track. PW engines will draw more amps. Modern engines will draw less. Lighted cars that use incandescent bulbs will draw more than LED versions. Multiple trains on the same circuit will also increase the amperage.

So, as Rob stated earlier, the answer to your original question is -- it depends.

From what you describe that you intend to run, I would guess that 8A would be a good starting point. That should kick in before the ZW circuit breaker and should not trip randomly as the load varies. 

Pete,

I run conventional, but modern—can motor—locomotives by Williams, Lionel, and K-Line, which generally pull 3–8 cars, some lit with incandescent bulbs. My first circuit breaker was 8A and it took a while to blow, so I went down to 5A, and then 3A. 3A was the sweet spot for me, it tripped quickly, but I never had false trips. Thermal breakers are cheap enough at DigiKey, that I would suggest getting a 3A, 5A, and maybe a 8A, and see which works best. You could probably get away with not getting the 8A.

—Matt

Thanks for the feedback Leo and Matt.

Cheers

Consolidated Leo posted:

RTR12: Tom, what video?

Oh dear, looks like someone forgot to add a link...must have had a senior moment there. 

Thanks for pointing that out! This should help and I'll go back and fix the other post.  

bostonpete posted:

Consolidated Leo posted:

RTR12: Tom, what video?

I'm going to go out on limb and guess he means this video.

https://www.youtube.com/watch?v=aVeCPeeeRNk

 

Thanks, correct limb, that is exactly the video he meant... 

I also fixed the previous post. 

Straight from Lionel: