I know this topic has been beat to death but. Here is my question.
I am running a ZW and it has the new 15 amp circuit breaker in it. But I run 16 and 18 gauge wire off of buss bars to the LockOns. 14 Gauge feeding the bar but the bell button looks like it has 20 gauge or smaller wire going to it and it is right off the transformer and goes to the buss bar too.. So what fast acting breakers should I get to protect the wires. 10 or 15 amp?? I run two duel motor Dash 8 40 Cs lashed up at the same time so 4 motors at once. I also run a set of 218s with 7 lighted passenger cars. Those are my big loads I think. I have never seen any heat build up on the little wire going to the bell button under normal running but what if there is a short?, Lionel bell botton #5906. Here is the breakers I am looking at. I have TVSs all over the place as well.
http://scottsodds-n-ends.com/circuit_breakers.htm
Joined 1-21-2011 TCA 13-68614
Kev, From The North Bluff Above Marseilles IL.
The circuit breaker should be sized to protect the wiring. If you have 14 AWG wire use 15 amperes, for 16 AWG use 10 amperes, for 18 AWG use 7 amperes, for 20 AWG use 5 amperes. If you need more current than these numbers, then you need heavier wire. Sizing the circuit breaker according to the normal load is the wrong way to look at it. If you can be sure that the current will never be any higher than normal, you won't need the protection of a circuit breaker. The breaker is there to protect your wiring against abnormal currents, whether due to a short circuit or another overload.
Fuses and fast circuit breakers are safe; but slower thermal circuit breakers also allow harmless brief overloads without nuisance tripping. I suggest the automatically resetting type used for automobiles.
(By the way, "buss" with "ss" means "kiss". The kind of bus you're concerned with is short for the Latin word "omnibus", meaning "for all", and is the same word that we use for large passenger road vehicles, spelled with one "s". The word for an electrical bus has nothing to do with the Bussman company, even though they make electrical things.)
Bob Nelson
Thanks Bob, Glad your out there.
But I still don't understand why the Lionel sound activation button has such small wire? Goes against everything said.
I liked the item I showed because It would cover all 4 outputs on the ZW but I can do the auto type. I just thought fast acting would be better than after smoked wire acting. What is fact acting compared to a regular auto style? is the auto style fast enough? If so then I am good with them.
As for this? TMI.
Lionel made some not-very-safe stuff from time to time. The DC reducers (107 and 170) may be the best example of that. But putting a single circuit breaker in multi-output transformers is right up there. Whichever whistle controller you have with the small may be in danger if fed from a big transformer like the ZW. You probably should protect it at the lowest current that you can use, probably 5 amperes.
Thermal breakers effectively model the overheating of the circuits that they are meant to protect. Rather than tripping immediately, they warm up, just like the wiring, then trip before the wiring gets too hot. Their rating is meant to be the long-term current at which they will not trip.
(Pay no attention to that man behind the curtain nor to the words inside the parentheses if that's a problem.)
No problem there Bob. Your always a great help!!
I guess for me it is if I protect that small wire on the sound activation button will I be tripping the breaker just running the lashed up Dash 8s? 4 motors, Just seems stupid to have that button and it's small wires in front of all of that big wire, if you know what I am going at. I don't want to smoke any of the wires if there were a short when my back was turned.
Surely the circuit breakers should protect the wires. But in my opinion that is not enough. Were the breakers only sized to protect the wires then a short inside a locomotive (or other item) could mean cooked circuit boards. Over on the "other board" one poster recently had his layout catch fire reportedly due to a defective switch machine. In this case there were no breakers at all, and the wires were light. But the poster wrote that the source was the switch machine itself. One cannot write with certainty whether a properly sized breaker would have prevented the fire. It may have.
Electromagnetic circuit breakers generally will try faster than thermal ones.
Most circuit board components will fry at much lower amperage than the circuit breaker rating. Additionally, the circuit breaker (even so-called fast acting breakers) can stay engaged for a very long time at a current level just above it's rating (like 1 hour). A short in a circuit board will almost never be protected by the circuit breaker.
Bob is correct. The circuit breakers are used to protect the wiring, not the electronics.
Earl
Most circuit board components will fry at much lower amperage than the circuit breaker rating.
Wouldn't that depend on the rating of the circuit breaker?
Additionally, the circuit breaker (even so-called fast acting breakers) can stay engaged for a very long time at a current level just above it's rating (like 1 hour).
I understand that a thermal breaker takes time to heat up. I don't understand how a magnetic breaker could take any time to build up enough magnetism to trip. Either there is enough current to trip the breaker, or there isn't. What am I missing?
All of the Postwar Lionel transformers I've seen with internal breakers have thermal ones. Last year I picked up a very large Marx transformer at an estate sale. When I opened it to check it over, I was quite surprised to see that it had a non-adjustable magnetic circuit breaker inside. It also had a Carbon roller on the wiper arm.
I am not aware of any circuit breakers that would act fast enough to protect most electronics. Even so, a circuit breaker with a low enough setting to protect the electronics would trip every time you tried to run your train.
i was not referring to magnetic circuit breakers when I referred to tripping times as long as 1 hour for currents just above the circuit breaker rating. Almost all circuit breakers used with model trains are the thermal type.
Almost all circuit breakers used with model trains are the thermal type.
Postwar Lionel #91 circuit breakers are magnetic, adjustable breakers. They trip very quickly, and can be set to trip just above the expected load. They are manual reset, with a lamp under the reset button that lights up when the breaker trips (and has a load). Lionel's prewar external circuit breakers were also magnetic, but were not adjustable. I have not looked at them in a while. At least some had two terminals, which I think were labeled "high" and "low" for different trip thresholds. I think some were also made with only one range. II agree that it is questionable whether they would trip fast enough to protect a solid state component. They probably would trip fast enough to protect a trace from being ruined.
Over the years folks have reported damaged traces due to derailments.
As I understand it, the early toy train transformers had no circuit breakers. Folks were encouraged to by "external" circuit breakers, some of which were "magnetic' and have a very good reputation to this day -- if you can find one. There were no solid-state electronics to protect.
Next Lionel and some other manufacturers built circuit breakers inside the transformer case. They were thermal and according to the K-line Complete Service Manual for Lionel Trains were considered to be within design specifications for a Lionel ZW Transformer (postwar) if they tripped between 11 and 40 seconds. That's a long time, but the old ZW was rugged enough to withstand it. But the layout wires?
I have an old 1032 transformer (similar to the vaunted 1033.) Its breaker is frozen and won't trip under any circumstances that I can create. Needless to say, I have placed an external inline fuse on the output.
Nothing said so far eliminates the need for voltage-spike protection in addition to the breaker if you use Postwar transformers with modern electronic equipment.
Modern transformers use modern methods: circuit breakers, TVS-type devices and some sophisticated devices such as "fold-back circuits". I don't claim to be able to evaluate them, but it seems clear that as a general rule, the current-carrying-capacity of the wires on the layout must equal or exceed the maximum output current that the transformer can produce.
The point:
Right now, on the other toy train forum, there is a lengthy thread where an operator experienced a serious fire which originated with his layout and all but lost his house. There are also several posts about melted insulation, scorched areas, and other near-disasters.
My adviice is to read it, and then come back and re-read Bob "lionelsoni" Nelson's posts on this subject, certainly including wire size. Don't put it off -- posts quickly slide off the radar on that forum.
Try http://ogrforum.ogaugerr.com/displayForumTopic/content/12129987998543558
They were thermal and according to the K-line Complete Service Manual for Lionel Trains were considered to be within design specifications for a Lionel ZW Transformer (postwar) if they tripped between 11 and 40 seconds. That's a long time, but the old ZW was rugged enough to withstand it. But the layout wires?
The Aurotec and K-line Complete Service Manuals for Lionel Trains is basically a reprint of the Lionel factory serivce manual, which was available to authorized Lionel Service Stations. There may be a bit of supplimental information. The introduction indicates that the pages were re-arranged, and at least some editions have advertisements for a couple of reproduction parts they were selling.
Some Postwar transformers were made without circuit breakers too.
In the postwar era, Lionel offered two circuit breakers. #92 was a fixed value, thermal breaker that looked very much like a #90 control button. (Sometimes people mix them up). #91 was an adjustable, electromagnetic breaker that can be fine tuned to match the normal load. They trip just about instantly. I use these on all my circuits. They do have a design flaw. One can screw the adjusting knob down so tight that the breaker will never trip.
I also used them on any setups my kids used when they were small, and used them on the layouts that we used to set up for kids to run at public train shows. They always tripped instantly on a derailment. I put together a mini control panel, just big enough for a 1033, a 91 breaker, and a barrier strip. The transformer and breaker were wired with solder lug terminations to the terminal strip. The track power was connected from there.
There seems to be two distict points of view on sizing circuit breakers and wire. Some folks recommend sizing the wire to match the breaker in the transformer.Others recommend using external breakers to match the load / wire size.
IMHO, the external breaker solution is most similar to how modern homes are wired. My home has a 200 amp service with a fairly good sized main panel. I don't have wire heavy enough to carry 200 amps to each outlet. The panel has secondary breakers that allow lighter wire to be run thoughout the house.
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