If AWG Octopuss, has eight feet it does.
AWG is the measurement of a wire's diameter. Thicker wire carry more current; thinner wire carry less current.
Current capacity is product of Voltage x Ampereage minus resistance. Resistance increases with length of wire.
Wires coming to our monastery are rather thin. It is three phase, and on the pole the fuses are 100 Amps each. But that is at 7000 volts. Have transformer we do... At 120-240 volts lots of ampeers we have. We also have 100kw generator, just in case, after all we do not want our trans to stop running just because some big blizzard took out all of the power.
Looks like it is going to be plenty hot this week, I could really use a big blizzard about now. Anybody going to the Dairy Queen?
Oh Your Question.... Use as small a wire as possible (after all, wires are expensive) yet will deliver the loadings you require for the distance you need to run it. For a power bus, LION likes 14 Gauge wire, but if all him has is 12, he will use it. Him likes stranded over solid because it is easier to handle, bend and solder to.
For intermediate stuff 22 gauge is sufficient. For the wiring of turnouts, signals, detectors and relays him uses cables such as 25 pair cat 3 cabling (Go ahead, google that, I got a good deal on the stuff that way) but some of my wire is very ancient. It came from a 1920s vintage pipe organ. When it was removed from the church, the buyer, a restorer of organs, simply clipped the cables and left them behind, where I grabbed them up to the train room. Very interesting, no plastic or rubber insualtion on these guys, just string paper and wax. All of the conuctors were white, so I had to test them out as I installed them. They were in bundles of 11 conductors with 6 bundles in a cable. The organist tells me that one cable would connect to each manual on the organ.
Getting even finer, that is connecting inside of locomotives and trains, where the smallest, most flexible wires are required, and can be used because the distance (resistance) is short, him cuts of the tails of dead mice. Very fine cable, expensive to buy unless you are a collector of dead mice. Then is free they are.
So the line on the bottom dictates how you are going to use the wire, and what you can get away with.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
What AWG? You can run #12 wire further than #16 wire under the same load for the same voltage loss. The smaller the number, the bigger the wire, and the less resistence per foot. You can find charts for this and alculate your own voltage drop. Remember than you always need a complete circuit, so power to a point 20 feet away from the source travels through 40 feet of wire. Once you know how many feet of wire you have, use the chart to find ohms per foot. Multiply by your number of feet. Now you have the total resistence in the wire. Next you need to know how much of a load there is - this is NOT how much your booster puts out, but how much is actually used. You may have a 10 amp booster, but if that point 40 feet away never sees more than 2 powered locos and no lighted cars, the load isn't anywhere near 10 amps. More like 1 amp tops, maybe 2 amps if both are ancient locos with inefficient motors. Voltage drop in the wire is then calculated by multiplying the resistence in ohms by the current in amps. If the calculated voltage droop at teh far end is 1/2 volt or less than the calculated voltage drop at the closest point, you won;t even notice anything.
As a final check, do a quater test to make sure the circuit breaker can trip - too much loss in the wire is what causes an otherwise dead short to not be seen as a short by the circuit breaker. You just lay a quarter across the rails, do not press down. If your wiring is solid, this should trip the circuit breaker.
--Randy
Modeling the Reading Railroad in the 1950's
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