# Relationship between wire gauge and amps

### Selecting the Proper Size Welding Cables

Once the proper amperage is determined, though, it is critical, that the wire gauge used in the circuit is appropriate for the amperage of the. The following wire size chart is intended to be a general guide for wire size and amp ratings. Common US AWG wire gauges and amps ratings. Sponsored Links Because of the small gaps between the strands in a stranded wire, a stranded wire with.

Thank you for the excellent question Rick! Understanding the voltage and current limits of your cable s is absolutely critical to maintaining a safe transfer of electrical power between your devices.

All cables feature some degree of resistance to electrical energy.

## Part 1: Choosing the Correct Wire Size for a DC Circuit

When electricity is forced to flow up against this resistance, it releases energy into the environment in the form of heat. When cables are very thin, i. The electrical breakdown of a cable assembly is not a pretty sight. During my younger years when my electronics expertise was in its infancy, I once made the horrible mistake of wiring a 12V DC switch incorrectly on a project box.

The switch connected a 12V lawn mower battery to a radio transmitter. Upon engaging the mis-wired switch, the connection created a short circuit between the negative and positive terminals of the battery — effectively dumping up to Amps of current down some 18 AWG wire.

I watched in horror as the wire literally melted from the inside out, causing a flash-fire with the PVC wire insulation melting away like candle wax! The melted wire dripped onto the carpet and nearly started a house fire.

Electric Blanket Fire Fortunately, I was able to disengage the switch quickly before things got even worse, but literally in a matter of seconds, significant damage was done. Similar to dB in signal and power levels.

### Part 1: Choosing the Correct Wire Size for a DC Circuit - Blue Sea Systems

Metric Wire Gauges see table below Metric Gauge: In the Metric Gauge scale, the gauge is 10 times the diameter in millimeters, so a 50 gauge metric wire would be 5 mm in diameter. Note that in AWG the diameter goes up as the gauge goes down, but for metric gauges it is the opposite.

Probably because of this confusion, most of the time metric sized wire is specified in millimeters rather than metric gauges. Load Carrying Capacities see table below Definition: In other words, how many amps can it transmit? The following chart is a guideline of ampacity or copper wire current carrying capacity following the Handbook of Electronic Tables and Formulas for American Wire Gauge.

As you might guess, the rated ampacities are just a rule of thumb. In careful engineering the voltage drop, insulation temperature limit, thickness, thermal conductivity, and air convection and temperature should all be taken into account.