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Reply to "Theoretical Electrical Questions: Do more feed wires means less heat?"

From the point of view of voltage drop, or heat dissipation, or overall resistance,  three 18 gauge wires is the equivalent of one 14 gauge wire.

The actual number is 2.5 instead of three, but I don't know how you string half a wire

This assumes all your connections are good, and all the wires are connected to the same place at each of the ends.

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Voltage drop is calculated using ohms law.  14 gauge wire = 2.525 ohms/1000 feet,  18 gauge wire = 6.385 ohms/1000 feet.  (oddly enough, one is 2.5 times the other)

Voltage drop = current x resistance

Example:  5 amps (typical for our sound and steam equipped locos pulling several lit passenger cars)  will drop the voltage 4 x 6.385/100 = 3.2 volts in ten feet for a a single 18 gauge wire,  but only 1.3 volts for a single 14 gauge wire.   This is why you need smaller gauge wires, or the equivalent, in longer runs.

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Heating also depends on the current, but is a bit more complicated. If anybody REALLY wants me to, I can reply.  Suffice it to say, as others have, heating is irrelevant for our cases, its only the voltage drop that matters

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

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