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Bachmann 5 Amp Booster

Started by ripvanwnkl, March 20, 2007, 05:53:24 PM

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Hunt

Jerry,
On the other hand, using your example ---- based on a curve fit to MIL-STD-975 --- a single copper 22 AWG wire at 20 degrees C (68 degrees F) the Ampacity is calculated to be 4.2 Amps.

But this alone may be misleading as it does not take all the components and their material between the Bachmann power booster and the rail of HO E-Z Track Terminal Rerailer into consideration. So I don’t think such info negates the need for Bachmann to answer the question asked.   ;)

jsmvmd

Hunt and Jim,

Not knowing anything about electronics or wiring, what is the worst case that could happen with improper wiring of this beastie?

Thanks in advance.

Best, Jack

Hunt

#17
Quote from: jsmvmd on April 12, 2007, 12:18:07 PM
Hunt and Jim,

Not knowing anything about electronics or wiring, what is the worst case that could happen with improper wiring of this beastie?

Thanks in advance.

Best, Jack
Jack,
Using too small AWG wire in a circuit can result in fire. Not saying that will happen with mixing these components.

From Dave’s testing, he now knows, as he is using the components, he seems to be OK by his feel for heat testing.

Dave’s question about using the original red power to track wires from the 5-Amp booster is a good common sense question because,
  •  Dave stated the power to track wires provided with the 5-amp Booster appears to be a larger AWG wire. If true, there is a reason.
  •  Bachmann rates the output of the E-Z Command Control Center as one amp. From testing,  I know the unit is capable of just under 1.5 amps output to the track.  I don’t know how much over the 1.5 Amps and for what time frame the power red wire, its female plug and the rail connect components are designed to safely carry.



Jim Banner

The ampacity of wire varies depending on insulation and application.  For example, #22 wire used in a transformer winding is rated at low as 1 amp but in a cable with other wires, can carry 5 amps.  In open air, it can carry 8 amps at normal temperatures.  My advice is to avoid burying it in the styrofoam if that is what you use on your layout.

But even if you buried it in the styrofoam, the chances of starting a fire are remote.  If the wire got hot enough to melt the styrofoam, or even its own insulation, that melting would extract heat from the wire, tending to cool it.  Eventually, you would end up with bare wire sitting inside a open "tunnel."  If you have ever used a hot wire styrofoam cutter, you have probably noticed how the wire cools when cutting and if you stop cutting with the wire still in the styrofoam, it slowly forms an open hole around itself without reaching the smoke point, let alone the ignition point.  Also from working with hot wire cutters, I seem to remember heating in the order of 1 to 4 watts per inch of cutting wire, depending on the type of foam being cut.  If we were to translate that to #22 wire, 1 watt per inch at a resistance of 16 ohms per 1000 feet (.0013 ohms per inch) would require a current of about 20 amps to produce 1/2 watt per inch in a single wire or 1 watt per inch in two wires side by side.  The 7 amps of so that a B-mann booster can put out would cause only 1/8 as much heating.  Bottom line, in open air, no problem.  Encased in styrofoam, no problem, but I wouldn't do it anyway.
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