Eaton 3 Amp Circuit Breaker (Good or Not)

Without looking,  I have three PW and 1 tmcc pulmore that will trip a normal 3a breaker on peaks (Starting heavy, etc). Add lit passenger cars and it's a sure thing on half of them.

A 3a breaker is more of a can motor/command oriented item imo. Motor size and if the 3a rating is "peak amp freindly" or not, is what you need to know. 

Have a multi meter? Max amps used by any train(s) in your roster will partially determine the size of a good breaker choice. Speed/method of breaker can be seen as ways of addressing peaks vs normal constant amp draw. A board unit can benefit from a fast trip more than PW because of PW bulk of material is more tolerant of a short term overdraw. Thermal breakers also average the brief rises in amp draw inherit to the AC open frame motors high torque moments better.

Old transformers use thermal elements that trip on an "averaged current". They average out peaks that would likely trigger magnetic&electronics somewhat erroneously (I.e. PW loco end up requiring a larger magnetic/electro breaker rating than a thermal one, just to handle split second peaks ). 

Adjustable breaker #91 Lionel is a fast magnetic breaker made pre-war/post-war. Along with the transformers thermal breaker, tvs for board units is about all thats missing... unless you want a "fancy" high speed electronic unit.

Come to think of it... you didn't even mention the power supply used. (3a is less than a 1033's thermal and I think a CW80 even has 3.5 or 4a...?) 

I looked up the specifications on this breaker, it's a pretty ordinary thermal breaker.  If you want real protection, you need something much faster.  The fact that a 3A breaker "protected" the load and a 5A breaker didn't should tell the story.  The response curves suggest that you have to exceed the rating by 3x for ten seconds before it trips.

I believe the whole moral of that boring video was that you want a breaker that trips and doesn't automatically reset.  There are tons of breakers that fit that model.  I personally use a 2A thermal breaker on my test bench, and it regularly sees more than 2A without tripping.  If I'm in doubt, I have an old Lionel #91 magnetic breaker that I patch in, even though it's 70 years old, it still offers far better protection than modern thermal breakers.

The characteristics of thermal circuit breakers is why I use the Lionel Powerhouse 180W bricks for a real layout.  They have an excellent electronic breaker that trips very quickly in the face of an overload, milliseconds instead of seconds.

Very good points John in understanding the specs of the component and how it actually works versus what the load can actually handle before melting.

I need to add some protection since I still use vintage Z's and ZW's.  For that reason I don't run my Legacy stuff to much.  Any good suggestions for that scenario?

gunrunnerjohn posted:

I looked up the specifications on this breaker, it's a pretty ordinary thermal breaker.  If you want real protection, you need something much faster.  The fact that a 3A breaker "protected" the load and a 5A breaker didn't should tell the story.  The response curves suggest that you have to exceed the rating by 3x for ten seconds before it trips.

I believe the whole moral of that boring video was that you want a breaker that trips and doesn't automatically reset.  There are tons of breakers that fit that model.  I personally use a 2A thermal breaker on my test bench, and it regularly sees more than 2A without tripping.  If I'm in doubt, I have an old Lionel #91 magnetic breaker that I patch in, even though it's 70 years old, it still offers far better protection than modern thermal breakers.

The characteristics of thermal circuit breakers is why I use the Lionel Powerhouse 180W bricks for a real layout.  They have an excellent electronic breaker that trips very quickly in the face of an overload, milliseconds instead of seconds.

Regarding the Lionel 180 watt bricks, I have your old ZW with to of those bricks, but I need another power supply for my third track, and purchased a rebuilt KW from the "trans4mr" guy recommended here.

I was going to use the Z-1000 that I bought, as it has a pretty fast breaker built in as well, but have been given to understand that the Z-1000 is not the best way to go, and that the KW puts out better cleaner power.

So, all of that said, I need protection for for the track power from the KW.

Actually, the Z-1000 brick is just a transformer and puts out pure sine waves, just as the KW would.  Truthfully, the Z-1000 brick will be a lot more compact if you don't need variable power.

One knock on the Z-xxx bricks is the breaker is NOT a particularly fast breaker, it's an ordinary thermal breaker.  The only brick I know of with a modern fast breaker is the PH-180.  The PH-135 just had a thermal breaker, and all the MTH bricks have thermal breakers.

gunrunnerjohn posted:

Actually, the Z-1000 brick is just a transformer and puts out pure sine waves, just as the KW would.  Truthfully, the Z-1000 brick will be a lot more compact if you don't need variable power.

One knock on the Z-xxx bricks is the breaker is NOT a particularly fast breaker, it's an ordinary thermal breaker.  The only brick I know of with a modern fast breaker is the PH-180.  The PH-135 just had a thermal breaker, and all the MTH bricks have thermal breakers.

All good to know John,

I do need variable power, however, as I will be running several conventional locos. That means that I would need to use the Z-1000 controller, which chops the pure sine wave from the Z-1000 brick.

So here is the setup:
Locos:
- Conventional
- Lion Chief
- MTH Remote Commander

Power Supplies:
- Tacks 1 & 2 (Inner & Outer Loops - Lionel ZW
- Track 3 (Yard) - Lionel KW (I need breaker protection here)

Diodes: (Track supply via Star pattern)
- At all transformer outputs
- At all track supply terminal block inputs

Breaker suggestions?

Dennis Holler posted:

Very good points John in understanding the specs of the component and how it actually works versus what the load can actually handle before melting.

I need to add some protection since I still use vintage Z's and ZW's.  For that reason I don't run my Legacy stuff to much.  Any good suggestions for that scenario?

I've been using 10 amp automotive ATC fast blow fuses with my ZW and TIU/TMCC base. They probably aren't as fast as the breaker in a 180w brick but they are close. 

As long as you don't have a lot of derailments, 10A fuses are a great solution.  If you can find inexpensive magnetic breakers, they're great, but they're scarce as hen's teeth.

gunrunnerjohn posted:

As long as you don't have a lot of derailments, 10A fuses are a great solution.  If you can find inexpensive magnetic breakers, they're great, but they're scarce as hen's teeth.

So, I believe that I only need one more breaker for my trains, since I have the two 180 watt PH bricks, and only have three tracks.

This one is a bit pricey, but what is your opinion?
https://www.dccspecialties.com/products/psx_ac.htm

Then there are these for dirt cheep, and your opinion on these?
https://www.grainger.com/produ...kwid=productads-adid

Or these?
https://www.ebay.com/itm/42091...HptY-TO3&vxp=mtr

The PSX-AC is a fast circuit, it'll do the trick nicely.  The others are just ordinary thermal circuit breakers.

I've been told by others that external breakers do "nothing" to protect the trains and are strictly there to protect the transformer only. And adding external Breakers to an existing good working internal breaker is just a waste of money.  Not sure if I totally believe that though.  Is that true?  

Not really true, if they're sized right they will protect the whole circuit.  Obviously, there's no "absolute" protection for electronic devices running around on metal rails, but a properly sized circuit breaker with good response is a key element in any protection.

I use these from Digi-Key. Super fast. I had 5 A thermals that would melt a jumper wire before tripping. Same wire on these is instant trip.

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Those are one of the magnetic breakers I speak of.  Actually, those aren't the fastest acting ones, but they're way better than thermal breakers.

John H posted:

I use these from Digi-Key. Super fast. I had 5 A thermals that would melt a jumper wire before tripping. Same wire on these is instant trip.

Product Index > Circuit Protection > Circuit Breakers > Sensata-Airpax PP11-2-10.0A-XX-V

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Thanks for all of the info.

Are you using these in 5 amps as well?

The psx rules out conventional running. I believe I recall it needs a constant voltage over 12v.

John H, Your jumper wire couldn't hold 5a, so should have had a lower rated thermal breaker for the wire to be used. Or your breaker was bad.

Not burning the jumper with the new breaker is a decent show of ability, but yet kinda of misleading as compared example as example A is flawed making thermal seem unsafe; the wire choice is the usafe part.

As said,

gunrunnerjohn posted:

Not really true, if they're sized right they will protect the whole circuit.  Obviously, there's no "absolute" protection for electronic devices running around on metal rails, but a properly sized circuit breaker with good response is a key element in any protection.

  The magnetic breaker is about as fast as you're going to get at a reasonable price....( They can be touchy with peaks though. That's why I keep pointing at the adjustable #91... If I can run under a 10a setting, I'd want to. You want the lowest amp fuse/breaker you can get away with period.)

...But wire chosen should easily handle what you allow to cross it with a breaker, even with a magnetic one. A 10a breaker needs all wire to handle 10a without issue unless another fuse/breaker of lower value allows a step down along that path.

  A breaker or fuse is a weak point; the weakest point; placed in a ciruit on purpose to protect wire, switches, loads or the supply, and/or each individually.

  To give you an idea how far you can go with concept, my last road legal offroad buggy came with 8 fuses. When done, it had two fuse boxes and 72 fuses. 3 added gauges, foglight set added, radio removed, washer fluid motor removed.  All run in 2 looms, fore and aft. A burnt harness was not going to strand me hwy, tundra, or woods because of any one item, switch or wire shorting. Even my batteries, generator, regulators, and starter had fuses. (generator could be an emergency starter too)

  Lionel internal breakers do provide some protection across the board if you use a large enough wire gauge.   But it isn't ideal because each circuit should be evaluated and fused individually... then if you're lucky you can combine some and have lighter feeds put in place, etc. (there ARE some panel tap combinations for accessories that remain unprotected by internal breakers to throw another wrench in the works, lol) ...Also of mention, the thermal and point wear on the internal breakers is lower if it only gets tripped by occasional testing, so should live a long healty life with these others doing the dirty work.

  If you had multiple loads on the magnetic breaker; load A is fine but heavy, fat wire, and loco for load. Load B is lighter, it begins to faulter, & so draws hard on your undersized jumper, but still less load than the loco is using. The jumper is in jeapordy. The heavy load A is possibly going to mask the lower draw long enough for the light jumper to melt. No direct short, just a slow draw just over the lighter wires rated capabilty, maybe leading to a short

  I.e. I'm not too sure, but I'm afraid you guy are missing something fundimental. Even with magnetic breakers you can't just plunk down a high value 10a breaker then run undersized 3-4 amp wire and expect everything is as safe as can be.

 At that point, the magnetic breaker only protects certain fast draws and reacts to sharp resistance/peak issues, like direct shorts. It does not magically protect wire from ALL high draws.

  So, an underguage 4a wire's insulation melting down under a 5a slow build, slow-cook draw, because of 10a delivery capability and no spike to detect yet, the melt ends in a dead short....which, oops, finally trips it, but too late to help the wire and the other(s) now melted...is possible.

I can run my layout on 5A, but there was a long wait time for those breakers, so I got the 10A. 5A runs 4 DCS engines with smoke on. I realize small wires aren't totally protected, and I may still look for the 5A magnetics. I only have three MUs, but one engine in any one of the MUs will miss the watchdog signal about a third of the time, so I need to watch the ammeter at startup. A Dash8 will draw 8A trying to pull the engine that won't move, which used to trip the thermal, but now won't trip the 10A magnetic. It's just SOP to have my finger on the power button at startup for an MU.

John H posted:

I can run my layout on 5A, but there was a long wait time for those breakers, so I got the 10A. 5A runs 4 DCS engines with smoke on. I realize small wires aren't totally protected, and I may still look for the 5A magnetics. I only have three MUs, but one engine in any one of the MUs will miss the watchdog signal about a third of the time, so I need to watch the ammeter at startup. A Dash8 will draw 8A trying to pull the engine that won't move, which used to trip the thermal, but now won't trip the 10A magnetic. It's just SOP to have my finger on the power button at startup for an MU.

I found the 10 amp version that you listed, but no 5 volt listed at all.

gunrunnerjohn posted:

I looked up the specifications on this breaker, it's a pretty ordinary thermal breaker.  If you want real protection, you need something much faster.  The fact that a 3A breaker "protected" the load and a 5A breaker didn't should tell the story.  The response curves suggest that you have to exceed the rating by 3x for ten seconds before it trips.

I believe the whole moral of that boring video was that you want a breaker that trips and doesn't automatically reset.  There are tons of breakers that fit that model.  I personally use a 2A thermal breaker on my test bench, and it regularly sees more than 2A without tripping.  If I'm in doubt, I have an old Lionel #91 magnetic breaker that I patch in, even though it's 70 years old, it still offers far better protection than modern thermal breakers.

The characteristics of thermal circuit breakers is why I use the Lionel Powerhouse 180W bricks for a real layout.  They have an excellent electronic breaker that trips very quickly in the face of an overload, milliseconds instead of seconds.

You mentioned the Lionel #91 breaker, and I have seen it mentioned in several threads.
I am assuming that you are referring to the Post War version, which I have read is even faster than the PH-180. I also have read that it is adjustable.
Can they be found, and would it suffice for an every day use on my yard track transformer?

Also, it was mentioned that the PSX will not work for conventional running,
Is that true?

EDIT:  I just scored this off of eBay

https://vod.ebay.com/vod/Fetch...derId=90000330562678

None in stock at Digi-key. I'm ordering these.

For the fast breakers, I'd probably do with the 10A models if you need full track power.

PR11-1-10.0A-XX-V

gunrunnerjohn posted:

For the fast breakers, I'd probably do with the 10A models if you need full track power.

PR11-1-10.0A-XX-V

I bought on of these last evening on eBay.
Post War #91.

https://vod.ebay.com/vod/Fetch...derId=90000330562678

Your opinion?

No opinion, I can't see them.  You obviously pointed to something in your account.

You can't view these order details. To view this information, you must be logged into the guest or eBay account used to purchase this item. See instructions to view guest order details.

gunrunnerjohn posted:

No opinion, I can't see them.  You obviously pointed to something in your account.

You can't view these order details. To view this information, you must be logged into the guest or eBay account used to purchase this item. See instructions to view guest order details.

Yep, I linked to the order, rather than to the item listing.

gunrunnerjohn posted:

No opinion, I can't see them.  You obviously pointed to something in your account.

You can't view these order details. To view this information, you must be logged into the guest or eBay account used to purchase this item. See instructions to view guest order details.

It was one of these, again, Lionel Post War #91 breaker.

The one I bought was $25, in also box with instructions.

https://www.ebay.com/itm/Lione...5:g:LXoAAOSwtQNcHVF1

The one I use is the pre-war #91, eBay: 283432888176

The post-war one has similar operaiton and an adjustment, I have one of those around somewhere.  The pre-war just has a high and low terminal, not really sure what they equate to as far as current.  If the low trips too quickly, I use the high.

gunrunnerjohn posted:

The one I use is the pre-war #91, eBay: 283432888176

The post-war one has similar operaiton and an adjustment, I have one of those around somewhere.  The pre-war just has a high and low terminal, not really sure what they equate to as far as current.  If the low trips too quickly, I use the high.

 

 

From all that I have read, the Post War version is adjustable, and extremely fast acting.
Some say it is faster than the PH-180.
Not sure that is true or not, just what I have read.

gunrunnerjohn posted:

The one I use is the pre-war #91, eBay: 283432888176

The post-war one has similar operaiton and an adjustment, I have one of those around somewhere.  The pre-war just has a high and low terminal, not really sure what they equate to as far as current.  If the low trips too quickly, I use the high.

 

 

The Post War #91 is adjustable from 1 to 6 amps, and here is a writ up about it from TandemAssocuates.com.

https://www.tandem-associates....el_trains_91_acc.htm

Yes, like I said, I have one of those.  However, I found the pre-war one to be easier to use and more repeatable on my bench.

gunrunnerjohn posted:

Yes, like I said, I have one of those.  However, I found the pre-war one to be easier to use and more repeatable on my bench.

But the pre war version, being thermal, is much slower, and the post war bring magnetic, is much faster.

This being the case, am I correct in my belief that the post war would be the better choice for the KW powering my yard track?

The pre-war model is NOT a thermal circuit breaker, it is a magnetic circuit breaker and very fast to react.

gunrunnerjohn posted:

The pre-war model is NOT a thermal circuit breaker, it is a magnetic circuit breaker and very fast to react.

My mistake.
I did actually read, on another popular forum that the Pre War version was a thermal breaker, but upon checking I see that this was erroneous information.
That also explains why you use one on your test bench.
I was a bit curious about that.

In one of your posts, above, you mentioned "However, I found the pre-war one to be easier to use and more repeatable on my bench".
Would you mind elaborating a bit on that?

And again would I be better off using one over the other on that KW transformer?

The pre-war one is simple, hook up to the LOW terminal and the common, and I have a low value magnetic circuit breaker.  No chance of the dial getting bumped and giving me more amps than I want.   Besides, I found it first and started using it.  When I got the post-war one, it worked, but I didn't want a dial to fiddle with. 

gunrunnerjohn posted:

The pre-war one is simple, hook up to the LOW terminal and the common, and I have a low value magnetic circuit breaker.  No chance of the dial getting bumped and giving me more amps than I want.   Besides, I found it first and started using it.  When I got the post-war one, it worked, but I didn't want a dial to fiddle with. 

Understood completely.
Thanks for the explanation.
I will probably get one.

Well, I received my, new to me, Lionel Post War #91 circuit breaker, and today I bought a very nice condition Pre War #91.
I will try them both on the KW for my storage yard, and see which I like the best.

Thank you all for all of the helpful information on this subject.