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I was running my eight car Daylight Special consist of K-Line 18" heavyweights and a Williams GS-4 and after approximately 8-12 laps around the track the breaker on my Z-1000 would trip. Of course, the train would stop. After about 20 seconds the breaker would reset itself and the train was good for another dozen laps or so.

I took the problem to the techie at my LHS and this is what he told me.

Each cars has four lights. So, that is 8 x 4 or 32 separate bulbs. As they heat they draw more current and exceed, along with the engine, the capacity of the Z-1000's breaker.

He said that the breaker gets a little more sensitive with age. It might be 5 or 6 years old by my best recollection.

His suggested solution was to either reduce the number of cars on the train or replace the bulbs with LED's.

What do you think?

Last edited by Rich Melvin
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That's always the issue with incandescent lamps, they draw much more current than LED's, plus the more the breaker trips the weaker it gets over time. Its not really measurable  but they do get weaker with age and use. You could buy a Z4000 and have a whopping 10 amps at your disposal

Each car probably draws around 1/3 of an amp, so you're knocking on the door to three amps with the eight cars.  Hot bulbs do not draw more current, if anything they'd draw less.  However, given the temperature of the filament in the bulb, a slight difference in the ambient temperature outside the bulb would not have a measurable effect.

My guess is the breaker is probably going bad, they do die.

PLCProf posted:
Michael Hokkanen posted:

 After about 20 seconds the breaker would reset itself and the train was good for another dozen laps or so.

 

What do you think?

Well, none of my Z-1000s have self-resetting breakers! Are yours supposed to do that?

Mine either...also i have 7.5 agc fast blows between my z1000 and TIU channel inputs.. ie circuit breaker @ z1000 rarely trips.

Last edited by willygee

If you can get your hands on an AC wall power-meter, in a few minutes you can get a good handle on how much power is going into your engine/cars.

z1000 on power meter

Plug the meter into the wall outlet.  Plug the Z-1000 AC power cord into the meter as shown above.

Z1000 on power meter chart

To be absolutely clear, this measures power going INTO the Z-1000.  But it can be a hassle and expensive to assemble the instruments/meters to make accurate power measurements of what's going to the track.

With no load on the Z-1000 (nothing on the track), the meter says 8 Watts which is the overhead or idle power.  Then I loaded the track with 10 Watts, 20 Watts, 30 Watts...etc.  The chart speaks for itself.  Reading the power meter Watts gives a good idea of how much power the Z-1000 is delivering to the track. 

These power meters have come down in price recently.  I got my no-name meter for less than $10 (free shipping from Asia) on eBay.  The most recognized name in the US is probably the Kill-A-Watt meter - less than $20 at Home Depot.  My public library even has them on-loan so you can check them out like a book!

P.S. A gold star to anyone who suggests the significance of the slope of the line.

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  • Z1000 on power meter chart
  • z1000 on power meter

I don't think so, each point on the line defines the efficiency at that point, the slope will be the incremental change in input divided by the incremental change in output, but that is not the efficiency.

Picture a horizontal line, slope zero; the input would be the same regardless of output, the efficiency would change with load, but it would never be zero.

I am trying to think of some physical transformer/circuit parameter that might be explained by the slope. I am pretty sure I can define the slope in terms of reflection coefficient or SWR or some such, but I doubt that is what Stan has in mind.

Last edited by PLCProf

LOL.  Yes, the devil's in the details!  What I have in mind, or what I'm imagining, is some simple and inexpensive method the average OGR guy can use to get a clue about power requirements.

I was thinking by dropping out the fixed/overhead power (8 Watts just for plugging the Z-1000 into the wall), the slope of Power Out vs. Power In would be the incremental efficiency (about 80% for this Z-1000).

So how would it work?  Say you add 5 lighted cars to the track and the power meter goes up 25 Watts.  Because the transformer's incremental efficiency is 80%, this means only 20 Watts (80% of 25 Watts) is going to the cars.  Now I have a bead on what the bulbs are drawing.  Then you start the engine pulling slowly and the meter goes up, say, 50 Watts.  Again, use the 80% slope and that suggests only 40 Watts (80% of 50 Watts) is going to the engine.  Remove the lighted cars and again some simple math to estimate how many Watts it takes to pull the cars at different speeds...it may be that even if going to LEDs there's not enough transformer power to pull a long consist of heavy-weights.  And so on.

Remember we're just talking here! 

As I have posted in other threads, I gave up on watts years ago. All the current O-gauge power sources are limited by their current output, not the wattage; wattage is just a legality for UL and a marketing tool that lets manufacturers use big numbers! Just do it in amps, that's all the transformers and circuit breakers really care about!

Don't the HO guys rate their stuff in amps?

Actually, to continue down your path, measuring the primary current/power is a good way to see if a transformer is at or near overload, but the math involved in calculating output headroom in amps or watts is likely to be unpleasant to many. I think I'd just recommend not loading past 80% of rating as measured with your Kill-A-Watt.

 

 

Last edited by PLCProf
PLCProf posted:
Actually, to continue down your path, measuring the primary current/power is a good way to see if a transformer is at or near overload, but the math involved in calculating output headroom in amps or watts is likely to be unpleasant to many.

The way to deal with this is to come up with an Excel spreadsheet that does the heavy lifting, then anyone could use it.   Do I hear any volunteers?

Michael Hokkanen posted:

I used separate bus bars for accessories. Track bus bars have each 4 connections to each part of the assigned track oval. So, the Z-1000 in question supplies power to a (roughly) 11' x 10' circle of track using 4 leads.

Michael,

It is my understanding that the accessory output is still a use of the available power of the transformer. 100 watts total. Remove one of the accessory leads at the transformer and observe if the train and car combination still kicks the breaker.

Lighted buildings and street lights are like the lighted cars when they are lit with incandescent bulbs.

If you have a separate Z-1000 for the accessories, then the point is moot.

The total draw of the layout could have the breaker just on the edge.

We are using 4  Z-1000 on the museum layout (EagleScout project). None of them are new. I had to separate the AC accessory feed to just a Z-1000 brick. I like the way the breaker operates. It's quick and requires the power to be turned off to reset it. We needed that safety factor for that environment. It's intended to be operated by non-train folks unattended by one of us.

I managed the power draw by using a small inexpensive clamp meter from Harbor Freight  Set it to AC amp and place the clamp around a wire from the transformer while the layout is operating.

Last edited by Moonman

Jumping on a bit late, but yes, typical thermal circuit breakers do become weaker over time.  The internal parts wear from use and much like old springs in a car can no longer hold car at proper level the moving parts in the breaker can no longer handle as much current.  

While you may or may not be able to find the exact same part, there are hundreds of choices out there for replacement breakers and it is likely you can find one that will fit in the same hole in the brick with little trouble. A quick look at Digikey shows breakers of a similar style and rating to start at about $2.60.  

In the grand scheme of things, the Z-1000 is really just a mid-range transformer, not really intended for powering lots of incandescent lights or multi-motored post-war locomotives.  Converting to LED lights will greatly decrease the power demands of your layout, but switching to a more powerful transformer may also be a good idea.   Just don't think you need a monster ZW-L or Z4000 to replace a Z1000.  Even the monster transformers only provide 10 Amps to a single block of track.  

 

On a last note, I am also confused by this:  

Michael Hokkanen posted:

After about 20 seconds the breaker would reset itself and the train was good for another dozen laps or so.

Are there versions of the Z1K that have self resetting breakers?  If not, it's possible someone has already had a go at repairing this transformer and may have installed the wrong current rating breaker.  I can't say with certainty that my z1000 is correct, as I've found out it came from the factory wired backwards of how most of them are, but mine has a standard, run of the mill, 6 Amp thermal breaker that has to be pushed to be reset.  

JGL

Moonman posted:
Michael Hokkanen posted:

I used separate bus bars for accessories. Track bus bars have each 4 connections to each part of the assigned track oval. So, the Z-1000 in question supplies power to a (roughly) 11' x 10' circle of track using 4 leads.


If you have a separate Z-1000 for the accessories, then the point is moot.

This is the case.
JohnGaltLine posted:

On a last note, I am also confused by this:  

Michael Hokkanen posted:

After about 20 seconds the breaker would reset itself and the train was good for another dozen laps or so.

Are there versions of the Z1K that have self resetting breakers?  If not, it's possible someone has already had a go at repairing this transformer and may have installed the wrong current rating breaker.  I can't say with certainty that my z1000 is correct, as I've found out it came from the factory wired backwards of how most of them are, but mine has a standard, run of the mill, 6 Amp thermal breaker that has to be pushed to be reset.  

JGL

What happened was this, although it has stopped since I removed two of the cars - the breaker would trip and the green indicator light on the Z-1000 would go dim. After 20 - 30 seconds you could hear a barely audible "click" and the light would go back on. It was only then necessary to take the throttle to zero and power up again to run the engine.

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