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In building my large layout, I have connected two 180 Powerhouse bricks to one TPC-400.  (On my old layout, I was only using one per TPC). 

I am discovering that when there is a derailment causing a short, the circuit breaker does not activate on neither TPC or 180 Powerhouses and a lot of big and powerful sparks fly from the track, and I quickly turn off the power. 

However, when I only turn on one 180 powerhouse, and test out a short, the circuit=breaker on the TPC kicks in very quickly.

The amp limit for TPC 400 is 20.  Any suggestions on how to get the circuit breaker to work fast if there is a short when using 2 bricks to power a TPC?

Greg

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I did do some investigating and discovered that a lot has to do with where the derailment and short happen.  If the short occurs close to the TPC and bricks, the TPC trips quickly.

If the short happens at points farther away, it takes more time to trip or doesn't trip before I start to see smoke and have to cut off power.

So it seems like its a "distance" issue.  I could move the components in a more central location, but its strange that my TPC trips first and a lot of people say that the brick always trips first.  I have never had ANY of my bricks trip...ever.  Is there something I am doing wrong?

This is a known issue, or at least I've observed it in several locations.  When you parallel two PH180 bricks, that seems to confuse the electronic circuit breaker circuit and results in slow or no trip.

The obvious question, do you really need to put 20 amps on the track?

Jon,

It's a 30' X 40' layout with inclines.  I want to run double, triple, or maybe quadruple steam headers with multiple smoke units pulling long freight trains.  Many freight cars will be the K-line die-cast hoppers, so far I have collected about 18 of them and plan to get more...they are HEAVY!  I also have many passenger cars that have not been upgraded to LED's yet.  I am still building the layout, so I have not done these type of tests with long trains etc.

Do you think I can get by with just one PH 180 Brick per TPC?

Greg

Last edited by Gregcz1

When IC Controls introduced the TPC-400 (late 90s?), I bought one, powered it with a 20A transformer, and used it on a large show layout.  I ran three post-war lighted passenger trains drawing over 10A.  A derailment could be "interesting" with pitting on the offending metal parts - just a bit short of spot welding.  That was my impetus to investigate fast circuit breakers.  The TPC breakers are thermal breakers with a significant lag in tripping when shorted.

The Airpax salesman queried my order of 10A instant trip magnetic breakers stating the only application he could think of was protecting electronics downstream of the power supply.  Exactly.

An application sheet for another type of reset-able breaker suggested paralleling breakers to divide the current load - the more sensitive breaker trips first and the second trips instantly thereafter.  With the goal of selecting a max amperage of 10 or 20 amps, I paralleled 2 10A Airpax breakers and rigged up resistance coils to sink high amps.  I found the paralleled Airpax breakers consistently tripped at 15A, not the expected 20A, for a resistance load.  This suggests electrical behavior with paralleled breakers that is beyond my ability to explain.

So now we have the OP's setup pushing 20A from paralleled Powerhouses through a TPC400 that chops the AC waveform to modulate track voltage.  The Powerhouses have an overcurrent protection circuit that works quickly when directly powering the track.  But the TPC's Triac alters the AC current and how the Powerhouse senses a short via the TPC is an unknown.   How the division of amperage between the twin Powerhouse's overcurrent circuits is also TBD.

If one of the paralleled Powerhouses is turned off, does the single unit sense the short instantly?  Will the paralleled Powerhouses trip when the TPC is not in the circuit?

Inserting an Airpax instant trip magnetic breaker between the TPC and the track would be good insurance.  The TPC's thermal breaker is inviting trouble since the Powerhouses are not reacting as expected.

The Airpax (under the Sensata corp) Snapak magnetic hydraulic breakers I use have a part number of PP11-69-10.0A-XX-V.  They are single pole push-pull buttons (PP11) which are typically special order.  The "69" portion of the part number is trip delay.  "69" is instant.  "61" is fast.  Sensata has a configuration tool to pick the style, delay, and amperage.

The electronic suppliers show lots of Snapak breakers.  When ordering, make sure the part number matches what you plugged into Sensata's configuration tool.

Last edited by Tracker John
@Gregcz1 posted:

Thanks, but I do NOT know how to "investigate" the issue.  All of my commons are connected to each component.

Also, what information can you provide on the fast-acting fuse so I can order some.

Thanks,

Greg

A commercial message to also consider fuses. These are the ones I use - look for the term fast blow and you can find holders to fit the dimensions.  these are 6x30 mm on amazon.

They can be installed in a number of ways and locations to support how you wire your layout.

102_8664a102_8666a

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@hokie71 posted:

A commercial message to also consider fuses. These are the ones I use - look for the term fast blow and you can find holders to fit the dimensions.  these are 6x30 mm on amazon.

They can be installed in a number of ways and locations to support how you wire your layout.

102_8664a102_8666a

@hokie71 said this much better than I could.    The fast acting fuses are cheap insurance.

George

If you're going to use fast blowing 10A fuses, what's the point of having 360 watts going into the TPU?  Just use one PH180 and you get the benefit of it's excellent circuit breaker and never have to replace a fuse.

Not that I would admit to being an incompetent operator with multiple derailments but....

Oddly enough, 90% of the time, my fuses blow before the PH 180 breaker trips.  This might speak to the quality of the fault connections I create when things derail!  As you can see in my picture, I too am using a single PH 180.

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