As has already been posted, Lionel Postwar ZW transformers do have circuit breakers. They are designed to protect the transformer. It takes a lot of amperage, and considerable time for it to trip (11-40 seconds at 30 amps).
When there is a short, there can be hot spots, certainly hot enough to burn people and things. I do not see using larger wires are a solution because that practice can just move the hot spot. The feeder wire may not get too hot, but traces on circuit boards can melt, as can internal wiring on the trains and accessories. I was burnt one time by a steam locomotive's handrail when it shorted across the rails, and I touched it as I picked up the engine.
In addition, the internal circuit breaker would not protect a short across a combination of any two power terminals ("A" - "D"). There are many ways to accidentally create such a short.
IMHO, the best solution is using external circuit breakers, one on each non-common terminal, "A", "B", "C", and "D".
[quote user="lionelsoni"
What size wire were you using?
[/quote]
I would guess around 18 gauge. You know, the size that comes in boxes of old train stuff already attached to the lockon. I know better, but figured it's just a test loop, and the same chunk of wire has been running this train since before I was born. I'll certainly upgrade to 14, and possibly install a fast blow breaker in line.
John
Individual breakers like Earl described are a good way to allow use of smaller wire with big transformers. His 6-ampere breakers are safe with 18 AWG, and maybe even 20 AWG. They also correct the error that Lionel made in putting a single breaker in series with the common terminals of their multiple-train transformers.
For layouts of any significant size, the ability to use lighter wire safely turns out not to be very useful, since feeder wires at least as heavy as 14 AWG are probably needed to keep voltage drop tolerable.
Bob Nelson
The same thing happened to me with the burned carpet. My grandchildren were playing with a carpet layout that I had set up for them. My wife and I left to go to church and the grandchildren were playing with the trains with their parents for supervision. When I got home, I saw that the insulation on the wires were melted and the carpet was scorched. Their parents said that the red light on the ZW was on, but they did not know what the red light meant.
To prevent that from happening again, I built a circuit breaker box using the plans from from the DVD "Jim Barrett in the Backshop, Volume 8". I used 6 amp breakers instead of the breakers mentioned in the video and I also added TVS diodes across the inputs and outputs of the box to suppress voltage spikes. I can now use my ZW with all of the latest electronically controlled engines.
Here is a picture of the box:
Earl
It is a circuit breaker. It is designed to open the circuit when the current exceeds 15 amperes, after a delay which roughly models the heating of the internal and external wiring. It does protect both the transformer and your wiring to the track if you use wire with an ampacity of at least 15 amperes, that is, 14 AWG or larger. What size wire were you using?
The circuit breaker in the KWs and ZWs, etc., is not really a circuit breaker. It is a current limiter. When you short a ZW, the current is limited to about 15 amps, enough to get skinny little wires pretty hot. Use nothing smaller than 14 gauge for wire to the track unless you use individual circuit breakers for each circuit.
My KW and LW were moved over to accessory operation only, I use Lionel 135 watt bricks for train operation, they have super fast circuit breakers.
Bill T.
stebbycentralLucky for you you caught it when you did. That would have been difficult to explain to the insurance claims agent...
The adjuster would not have a problem with most of that scenario. The big problem would be trying to convince them that an ensuing fire resulted. Carpeting is flame retardant and is VERY difficult to actually burn, and would require copious amounts of accelerant(s) to get it going, if at all, past melting & smoldering.
Trying to pin the origin on appliances located on or near carpet as a combustible substrate is a very common arsonist's "mistake".
Rob
The circuit breaker is probably fine - it is meant to protect the transformer, not the wires or the train.
Your wiring was most likely too small.
Lucky for you you caught it when you did. That would have been difficult to explain to the insurance claims agent.
"Honest! My house caught fire as a result of a locomotive derailment!"
I have figured out what is wrong with my brain! On the left side nothing works right, and on the right side there is nothing left!
Hi,
I was just running one of my engines on a carpet loop in the basement, and noticed it stopped. The track came apart and the engine derailed, and when I went over to investigate I could smell burning insulation. The wires to the track clip got hot enough to burn a nice track in the carpet. Looks like the ZW needs a new circuit breaker, and hopefully I can doctor it up so the wife doesn't find out. Luckily the damage is minimal, but be sure to watch those old transformers.
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