Wire type/size vs voltage/amps

14ga copper stranded wire will handle 24V AC, regardless of the "name" of the wire, ... i.e., "speaker wire", "hookup wire", "house in-wall wire" ... it's all the same really, except maybe for "twisted pair" vs "solid" vs "plain stranded" ... all makes no difference, correct?

And it will handle any amperage our Z4000 will put out at 24 volts, correct?

The only difference I can see is the price charged for the exotic labels (like $300 for 200 feet for "high-fidelity"" quality speaker wire vs $36 for 250 feet of "low oxygen stranded copper speaker hookup wire") or who is selling it (stereo store vs Amazon vs eBay).

Yes, it's the same?

 

 

Original Post

14 gauge will handle 15 amps.

12 gauge will handle 20 amps.

Google "ampacity of copper wire"  Even though my spell check says that "ampacity" is not a word, trust me, it is.

The cheapest way to get stranded 14 gauge is to buy the cheapest construction-site extension cords at Home Depot.

Avoid anything that says it's for fancy home speaker systems. You're paying for hype.

Arthur P. Bloom TCA 86-23906 "I love the smell of smoke pellets in the morning!"

Two tidbits that are often overlooked when dealing with wire gauge is that the charts you find on the internet are typically generated based on a target voltage drop, or the type of wire insulation. 

For example, the NEC (code that defines electrical wiring for US homes/industries/etc) states that 14AWG wire is rated for 15 Amps at a given temperature and a given wire length (300 feet in most cases). There is also a consideration for the number of conductors (or wires) that are stuffed into a small area ( like a 0.5" conduit).

When in comes to train wiring, an often overlooked but very import aspect is the quality of the connections/splices that are used. A bad splice (one with high resistance) can have more impact on train wiring than  16AWG wire vs 14 AWG wire.

Long story short, a 14AWG wire can handle more than 15 amps for a short distances (less than 300 feet). And wires that have heat resistive insulation can carry higher currents than those with low cost plastic insulation. 

To the original poster comment, 14AWG is a measure of size.  Which wire you ultimately choose should be based on how you plan to use it, not just purely the size gauge. 

 

 

 

enginEErjon posted:

Two tidbits that are often overlooked when dealing with wire gauge is that the charts you find on the internet are typically generated based on a target voltage drop, or the type of wire insulation. 

For example, the NEC (code that defines electrical wiring for US homes/industries/etc) states that 14AWG wire is rated for 15 Amps at a given temperature and a given wire length (300 feet in most cases). There is also a consideration for the number of conductors (or wires) that are stuffed into a small area ( like a 0.5" conduit).

When in comes to train wiring, an often overlooked but very import aspect is the quality of the connections/splices that are used. A bad splice (one with high resistance) can have more impact on train wiring than  16AWG wire vs 14 AWG wire.

Long story short, a 14AWG wire can handle more than 15 amps for a short distances (less than 300 feet). And wires that have heat resistive insulation can carry higher currents than those with low cost plastic insulation. 

To the original poster comment, 14AWG is a measure of size.  Which wire you ultimately choose should be based on how you plan to use it, not just purely the size gauge. 

 

 

 

Is the capacity of the wire the same for 120V AC as it is for 24V AC?  15 amps at 300 feet for either, 24v or 120v??

Yes, no offense to the previous post, but I think for our usage he's making this way too complicated!  The one key point that I certainly agree with is the quality of the connections is usually more important than the size of the wire.  Obviously, you need sufficient wire size for the current draw and the maximum voltage drop you can tolerate.

If you run a #14 wire pair 20 feet with a 10 amp load, you'll drop about 1 volt.  Using #12, you'll have a .65 volt voltage drop.  In either case, the heating of the wire, and thus any temperature specification, is insignificant.  In that #14 example, you are dissipating 10 watts over a 20 foot span of wire pairs, you won't be able to detect the temperature rise without a temperature measurement instrument.

We're not trying to launch the space shuttle here.

gunrunnerjohn posted:

Yes, no offense to the previous post, but I think for our usage he's making this way too complicated!  The one key point that I certainly agree with is the quality of the connections is usually more important than the size of the wire.  Obviously, you need sufficient wire size for the current draw and the maximum voltage drop you can tolerate.

If you run a #14 wire pair 20 feet with a 10 amp load, you'll drop about 1 volt.  Using #12, you'll have a .65 volt voltage drop.  In either case, the heating of the wire, and thus any temperature specification, is insignificant.  In that #14 example, you are dissipating 10 watts over a 20 foot span of wire pairs, you won't be able to detect the temperature rise without a temperature measurement instrument.

We're not trying to launch the space shuttle here.

Got curious once and measured the drop from the transformer to the furthest point about 25 feet out and it was just that, John .. a one volt drop at 22 volts.

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