To all: Thanks. We're set.
What is important is to have the wire ampacity no less than the overcurrent protection. You can do this either by increasing the ampacity or by protecting at a lower current. I have often suggested the latter; but it seemed unnecessary in this case, since the CW-80's protection is appropriate for the proposed wire. As I said above, "22 AWG should be okay."
Bob Nelson
If you're really nervous about the #22 wiring, put a fuse in line with the accessories. Running #14 wire to everything is expensive and totally unnecessary.
o A few years ago, the NEC allowed equipment grounds to be two AWG numbers smaller than the circuit conductors.
o Canada forbids the US practice of putting 15-ampere recepticles on 20-ampere branch circuits.
o Until recently, the NEC allowed ranges and clothes dryers to use the grounded conductor as an equipment ground. (The NEC Handbook actually apologized for this inconsistency.)
o Before lamp cords were required to be 16 AWG, they were 18 AWG.
o The British put fuses in their plugs so that the cord ("flex") is protected at its appropriate ampacity.
Different countries' rules allow interestingly different exceptions to rational practices. But the overall history of electrical codes, which I have followed for many years, shows a continuous incremental elimination of these. About the best excuse for using lamp cord smaller than can carry the current that it might have to carry is that it's out in the open--at least the NEC requires it to be--where someone might notice if it starts to burn.
I don't see any reason to wire your accessories for the full transformer rating. Think about your lamp cords that are #16 wire plugged into a 20A outlet. Do you really want to wire all your home appliances with #12 wire? Have any idea how thick the cords to every appliance would be?
Tons of accessories are wired with #22 wire, let's not get carried away here.
Although it's not as urgent as when powering trains, since overloads are less likely, you should really size the wire according to the transformer's overcurrent protection, not what the load(s) draw. For the CW-80, that is probably around 4 or 5 amperes. If so, 22 AWG should be okay.
BOB: First of all, thank you. Every time I read one of your posts, I learn something. (Whether I remember what I read is another thing!)
Looked at the instructions for the items that I listed and could not see any electrical information other than that they operate on 12 - 18 volts. On this small layout we will be using a CW80 transformer with 14 AWG wire for the power. Reason I posted the questions is that we have a lot of the 22 AWG wire on hand and thought we would use it for the accessories.
BOB: See next post
Twenty-two AWG wire is safe for a circuit that is current-limited (as by a circuit breaker or fuse) to about 4 amperes.
A rule of thumb is that 10 AWG is safe for about 30 amperes, 12 AWG for about 20 amperes and that the ampacity (safe current-carrying capability) drops by half every four gauge numbers above that.
Yes or No answers will be just fine. #1 Is 22 AWG too small for Lionel accessories such as the Highway Lights and Passenger Station Lights? #2 Is 22 AWG too small for Lionel accessories such as the Automated Gateman and Crossing Gates? As always, many thanks.
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