"Overwiring" Question

[Anonymous]

Here's something I've wondered about long and hard, but never read an answer to, and if any of you know the answer, I'd really love to hear it:

Aside from cost, are there any problems with "overwiring" -- that is, using wire that is larger gauge (smaller AWG values) than needed for the task? For example, if an accessory calls for 22 gauge wire, are there any adverse consequences of using 18 or 20 gauge wire (again, aside from the cost differential)? For that matter, are there any benefits? I know larger gauge wire means lower resistance, but what are the consequences of that as far as accessory, circuitry or transformer operation?

Thanks.

Bob
Houston, TX

[Anonymous]

A heavier gauge will not hurt anything as long as connectors accept it. Unless you run a long distance there is really no benefit as long as you do not exceed the wires capacity. You should always use appropriate fuses or circuit protection.

Dale Hz

[Anonymous]

QUOTE: Originally posted by rwest

Aside from cost, are there any problems with "overwiring" -- that is, using wire that is larger gauge (smaller AWG values) than needed for the task? ..... Thanks.

Bob
Houston, TX

None that I have ever come across except if you are trying to hide the wires or if the larger diameter wire is too siff to bend the way you need it to. In longer wireing runs the larger diameter may be required to minimize power drop due to the distance traveled.

Steve

[Anonymous]

Thanks for the insights, Dale.

Bob

[Anonymous]

And thanks to you, too, Steve.

Bob

[lionelsoni]

I agree wholeheartedly with Dale's advice: "You should always use appropriate fuses or circuit protection."

Let me say it the other way around too: "You should always use wire heavy enough for the the circuit protection that you've got." Often the circuit protection comes first--whatever is in the transformer--and then the wire is added, too often without considering what the transformer can put out and without adding external protection if the wire is too small for the transformer's circuit breaker.

[Anonymous]

"are there any adverse consequences of using 18 or 20 gauge wire"

Electrically, no. Physically, maybe (issues of stiffness/flexibility). Economically, yes. Impact on your wallet. The more conductor in the wire, the more it costs.

[phillyreading]

Don't know if Lionel still does this but they used to give you some wire with the accessory like the crossing gate or highway flashing lights and the wire looked to be very small around a 20awg, in my opion you need to replace it with at least 16awg for most transformers or at least with a postwar ZW.
Lee

[palallin]

chuckn is certainly right about the $$$ impact. I just spent about $50 on two spools of wire, a connector strip, and two plug connectors for the main bus for my 3-rail mainline and siding. The cheapest I could find 12 AWG was $16.99 + tax per 100' spool. But 12 AWG is the minimum I'll be happy with for that bus. I use 12" 16 AWG feeders to each piece of rail. Considering the current draw of a heavy train on my steepish grades, I want to be sure that the power gets to the engines.

[Anonymous]

Thanks chuckn, Lee and pallalin, for the insights.

Chuckn, are you proposing somehow protecting the circuit above and beyond what protection the transformer provides? How would I do that -- inline circuit protectors of some sort, and if so, how many amps protection (or how to figure out how many amps maximum)?

Bob
Houston, TX

[lionelsoni]

I think you meant me, not Chuck.

Yes, I am. If, for example, you had a transformer with a 15-ampere circuit breaker (ZW or Z), and wanted to wire with 16 AWG wire, you should put a 10-ampere fuse or circuit breaker in series between the transformer and the track. Approximate ampacities for various wire sizes are

10 AWG, 30 A
12 AWG, 20 A
14 AWG, 15 A
16 AWG, 10 A
18 AWG, 7 A
20 AWG, 5 A

I like the automatically-resetting breakers that you can find at automobile parts stores, which are very similar to those built into the transformers.

Another important reason for adding external circuit breakers is to correct the shortcoming of traditional Lionel transformers in that they have no protection against fault currents flowing between their multiple outputs. These currents can result from accidentally or deliberately (and unwisely) running trains between blocks powered by different transformer outputs.

[BR60103]

Electricly, larger wire will not hamper you, while smaller wire can act as a rsistor and heat up.
However, if you get a good deal on some used streetcar wire, you may have to add bracing to your layout to support it and buy a bigger soldering iron. [:D]