Sugar breaker question using post-war Lionel ZW

It seems odd that you are getting frequent trips of a 10 amp breaker. Are you running several trains with lit passenger cars? Are you getting lots of derailments and shorts? Your 10 amp breaker is tripping for a reason. If you switch out to a 15 amp breaker you should make sure you have nothing less than 14 AWG wire supplying your track feeds. Even then I would be worried that if you have a derailment with a 15 amp supply you could run the risk of frying the small gauge roller wires in your engines. I am not familiar with the digipace diodes. What function do they play?

Rod

Sweet!

No, a 15 amp breaker is not safe.  Find the fault or faults that are causing the blown breaker.

The fault could be caused by a car, engine, junk on track, loose connections, overloads, etc.  You may have a small wire crossed somewhere.

Calculate your load/watts.  See Load Calculations and do the math.

I thought so . Much thanks for your replies.

Thanks again, Jerry

A ZW should not be called upon to furnish more than 10 amps aggregate over its 4 outputs.

Lionel's factory service manual stated that the "250 watt" ZW transformer could continuously supply 180 watts at 14 amps. 

The internal ZW circuit breaker test was specified as a 30 amp load taking 11-40 seconds to trip. Which is one of the reasons why I always suggest using external breakers with ZW and other large Lionel transformers.

I use automotive atc style thermal breakers with my ZW.  If I want to protect a 10 amp circuit, I use a 7.5 amp breaker.  A 7.5 amp circuit gets a 5 amp breaker.  Traditional thermal circuit breakers are very slow acting.  The way I do it may be a bit of over kill, but with the cost of today's electronics I'd rather be safe than sorry.   I also use TVS's with my ZW for every feed.

If you are consistently tripping a 10 amp breaker, you really need to look at why.  I run 2 MTH dual motored E8s with a set of incandescent lit passenger cars on the 5 amp breaker with no issues.  I've seen setups running more than 4 powered units on a traditional 10 amp fused circuit with no issues. Maybe you could post the specs of the digipace diodes you are using and how they are wired in. 

Tony

While watts being drawn may affect heating of the transformer as a whole, the heating effect in any segment of wire is strictly dependent on the amperage flowing through it.    Thus, while drawing, say,  20 amps with the voltage set at 8 volts is within the wattage rating of the transformer, a portion of the secondary windings will be seriously overheating.  I suspect the tiny contact point between roller and winding will be very hot.

Working backwards from a later ZW rating of 275 watts and max voltage of 20, and applying the 1950's Lionel suggestion not to draw 70% of power continuously from a ZW, I compute the 10 amps as a safe load.  Note that this does not mean that 10.0 is safe and 10.01 is not.  The heating effect is gradual.

Thanks again guys preciate it ,jerry