Z4000

The Circuit breaker is designed to protect to the transfer when a short occurs, so yes what that tech told you was correct. How fast those breakers trip really depends upon the breaker itself. The z4000 breakers are pretty good, but not quite as fast as the breakers in the PH180 bricks.

The best protection for your trains (electronics) comes in the form of TVS Diodes installed throughout your layout. They will help prevent damaging voltage surges that can occur during a short.

There are other devices out there which are also excellent at protecting your electronics and transformers but using good modern breakers (or fast blow fuses) and TVS Diodes will do the job effectively.

OK, so why the external circuit breakers then? The 2 accessory breakers trip instantaneously, in the mean time the transformer is pumping 14 amps to the track for 7 seconds before the internal circuit breaker opens on either track. What is the purpose of the external reset buttons then?

Those two accessory breakers are much smaller in amperage rating (3 amps if I recall correctly). They will be easier to overload and trip.

The 10 amp breakers for the tracks are thermal breakers. When they are overloaded, they heat up and then trip once a certain temperature is reached. This is why you were able to load them with 14 amps for a short period of time. This is very similar in operation to how the thermal breakers worked in Postwar transformers.

Then what does it take to trip the 2 external breakers with the reset button. If they don't protect the track, what is their purpose? I don't think there are any thermal breakers in a Z4000.

Do you have a Z4000? can you short out your track for a second and see if one of the 12 amp breakers trip and have to manually reset?

Does anyone have a Z4000 they can check the circuit breaker for me?

The easy answer is breakers/fuses are protecting best when matched closely to each circuit draw as possible. The beakers in a transformer are matched for the transformer output. They also, but just by chance, do a fair job of protecting track & accessories, but they aren't matched to those . That external match is an unknown variable the user decides on.  In an ideal setting you fuse each item individually, one at a motor, one at the light, one at smoke unit, one at sound, one at track, one at wires, one at transformer etc..  

Being a "master of overkill" and wanting bullet proof electrical I added 72 fuses to a dune buggy.  Anthing goes wrong, from a light socket smashed to a branch poking through a floorboard; severing a wire bundle, the remains would be salvageable, and I might not have to walk 50 miles in wilderness.

The two externally resetable breakers on the Z4000 are for the 10 and 14 volt outputs, not the track voltage. Read your manual, it's in there.

Chuck Sartor posted:

Simple question. Should the 2 circuit breakers protecting the track power handles trip instantly when there is a short? I was told by MTH service the 2 circuit breakers do not protect the track, only the transformer itself.  This does not sound correct to me.

I was told the exact same thing by Don in MTH tech support after I bought my brand new Z4000 last spring. I thought something was wrong with it because the breaker didn't trip right away after a derailment. Don told me that is how it normally works, and he also told me the circuit breakers protect the transformer, not the train. He also told me a short caused by a derailment won't hurt the electronics in the train. 

Jobn 

Although the Z-4000 is a titular 400W transformer, the two handles are electronically limited to 10A and 180W per handle (360W total). The circuit breakers for the handles are (virtually*) impossible to trip under just about any scenario unless the electronic overload circuitry fails or an internal short develops. They act as a "last resort" in the event of a catastrophic internal conditions, not as any actual protection of the output to the track. The 10V and 14V accessory outputs are separate transformers that make up the remaining 40W but are not electronically controlled/limited, so a short/overload of either accessory output trips its respective breaker.

*I recall I did actually trip one by operating at the very cusp of 10A for around 3hrs, but this was not normal use. In my experience, a Z-4000 will maintain 9.9A indefinitely.

OK, seems strange that the accessory 10 and 14 volt trip instantaneously, but the other 2 are last resort breakers mounted right next to each other. There are 4 circuit breakers, not 2. The Manual does not go into any detail about their operation. The manual states each output has it's own circuit breaker.

OK Edit, I reviewed some older posts with the same question, and the answer is the same. The external breakers won't trip under normal operating conditions.  So I learned something.

 Überstationmeister hit the nail on the head. The overload protection in the z4000 for the tracks will kick in before the breakers have a chance to really do what they need to do. The smaller accessory breakers do not have this protection.

Getting those larger brekers tripp is hard to do, the overload light usually starts blinking long before those ever go.

H1000 posted:

 Überstationmeister hit the nail on the head. The overload protection in the z4000 for the tracks will kick in before the breakers have a chance to really do what they need to do. The smaller accessory breakers do not have this protection.

Getting those larger brekers tripp is hard to do, the overload light usually starts blinking long before those ever go.

Your overall wording is a bit better, I follow you folk fully now too.  I personally look at an electronic overload protection as a "self reseting breaker system". Some other power supplies rely strictly on electronic overload protection, no actual breaker or fuse is there. In these,cases power to the track is stopped till an overload is removed providing the same basic protection; off.   

  The speed it turns back on however could lead to damage where a breaker/fuse (even thermal) may actually protect better by being off and staying off (thermal ones off long enough to cool some, and cooling would also happen all the way to the short/overload too, a good thing.     I had read it all as ZERO protection on the track output, at least at first.   I see why they say there is no protection; the speed of the transistors switching 10a off and on allows no cooling.

  I still consider electronic protection some protection, but if I know I have ten amps capability, my wire to track will also be chosen to handle at least ten amps, or be fused/breakers to match the wires max. amp handling if I use smaller wire.  Most folk don't even consider this imo. They consider used power only. My buses are 10 & 12g at 18ft max. for 10a. (I use 10g on a graded track, 12g on flat)  My wires are not a weak link at 10a 20v shorted for 10 seconds, my internal breaker is; or fuses where placed are. 

"Oversized" wire can also have an unwanted effect on good delivery of some frequencies though.  They get weak;lost in the extra wire space. I don't run command so don't know for sure how large gauges may effect a command signal from these systems, but it seems (offhand) only some would be effected a lot, and a signal booster could overcome it. This is the case in some other purer serial lines anyhow

One reason I like the Lionel PH180 is the circuit breaker is electronic and fast, but when it trips, it stays off until I reset it.  I know others share a different opinion, but personally I don't want the power banging on and off if I have a short, I want to find the short first!

Chuck Sartor posted:

Simple question. Should the 2 circuit breakers protecting the track power handles trip instantly when there is a short? I was told by MTH service the 2 circuit breakers do not protect the track, only the transformer itself.  This does not sound correct to me.

Chuck, for instantaneous short circuit protection I've found that the MTH 40-4002 unit plugged into the Z4000 works.

https://mthtrains.com/40-4002

Don't know how or why though IIRC is was explained here on the OGR Forum a while back.

Thank you everyone for your input. I guess I should have known that already. To MTH: You should update your instruction booklet  ( and online ) that comes with the Z4000. Lionel on their transformer instruction sheets that came packed with the transformers included a paragraph on How the circuit breaker operates, and explained their operation. This is especially needed since their are 4 circuit breakers on the back, the 2 that are on the accessory are instantaneous, and 2 that are 'last resort' internal breakers and are not expected to operate except for catastrophic internal problems. Those two breakers should have been placed elsewhere when the Z4000 was designed. More information should be included about the seven red light blinks and automatic internal shut down.  

OK, now for the bare bones conventional user.

What manually resettable  breaker to be used between the Z-4000 or Z-1000 and the track?

Just a simple two wire connection directly from the transformer to the track.

What exact product part number and source to splice into which wire(s)?

Thank you....

If you want to look around, a Lionel # 91 is a great instantaneous illuminated adjustable circuit breaker. Although the MTH transformers have instant breakers already built in you have to understand how they work (on the Z4000.)

gunrunnerjohn posted:

One reason I like the Lionel PH180 is the circuit breaker is electronic and fast, but when it trips, it stays off until I reset it.  I know others share a different opinion, but personally I don't want the power banging on and off if I have a short, I want to find the short first!

John, if I recall correctly the z4000 requires the user to reset the handles to zero volts before power can be applied again. Then again, I may be wrong on that one, my z4000 has been packed away for a while now.

Also on a side note, Another nice feature of the PH180 bricks is that the breaker will automatically reset when you unplug the 120v input power from the brick that has tripped. Unplug and re-plug to reset makes it easier than getting to some of the hard reach places where the bricks gets placed.