Circuit breaker response time for a TPC?

That's odd. In my experience the breaker on the 180w bricks pops instantly,  while the TPC never does.

You need to figure out why the breakers aren't tripping. The bricks have some of the fastest acting breakers in the hobby.

Are your bricks connected to the TPC via the y adapter plug?

Greg,

I would investigate RickO's question, but I would also consider putting a fast-acting fuse in line between the track and any other equipment.

George

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

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?

John probably hit the nail on the head with the two tied together, but one by itself should definitely always trip before the TPC, I had one I found out the PCB in the PH was broken

@zhubl posted:

John probably hit the nail on the head with the two tied together, but one by itself should definitely always trip before the TPC, I had one I found out the PCB in the PH was broken.

That's probably going to inhibit operation of the circuit breaker!   Probably shouldn't be dropping those heavy transformers!

@gunrunnerjohn posted:

That's probably going to inhibit operation of the circuit breaker!   Probably shouldn't be dropping those heavy transformers!

What can I say it was on our modular layout so definitely more abuse than usual but I don’t remember dropping it, I did wonder why the TPC breaker kept tripping glad I finally found out why 😜

I have same set up, two 180’s going to Tpc. 400. My 180 trips immediately. Actually only one trips probably because it’s the first in line.

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?

@gunrunnerjohn posted:

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

Are you using proper power out cables shown below?

Well, I've run Legacy dual Centipedes with four smoke units on mine, with 30 cars, and the total power draw was right at 4 amps when on the grade, so you can get a lot out of one 180 watt transformer.  I know the risks aren't worth the reward, at least to me.

I'd try it with a single brick and only add the second if it turns out it can't handle it.

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.

@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.

@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.

@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.

@gunrunnerjohn posted:

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.

I paralleled 2 10A Airpax breakers and rigged up resistance coils to sink high amps.   

What part # Airpax breakers are you using, Tracker John??

I updated my previous post with my part number and a link to the Airpax Snapak configuration tool.

@Tracker John posted:

I updated my previous post with my part number and a link to the Airpax Snapak configuration tool.

Thank you!!!!!