How can thin wire in generator windings carry the high output current?

Question

I observed the rebuilding of a 12KW, 120V gas-powered generator. I was amazed at how small the generator portion was (roughly the size of an electric motor you might find in a major home appliance). The windings were pretty thin magnet wire, like you would find in an appliance motor.

Getting the 100A generator output to the breaker box requires heavy-duty wire. That same current originates in the generator windings. How is the thin wire in the windings able to carry 100A (which far exceeds what wire that size is rated for)?

Answer 1

Note: Small Gauge mean the wire can carry a significant amount of current. Example per the attach AWG 4-5 can carry 100A. There are lot other factors need to be considered before selecting a wire.

Below is guide line help you appreciate wire gauge vs current. This is purely a guideline. I suggest searching American Wire Gauge Charts vs Electrical Current load for additional information. Below are some links for you to get started.

References:

• Wire Gauge and Current Limits Including Skin Depth and Strength
• American wire gauge

Answer 2

My question was based on an appearance that the thin winding wire seemed to violate the laws of physics, so there might be some other factors at play. Neil_UK answers this in generator coils: max power given wire gauge on the Electrical Engineering site. The bottom line is no. It's mainly a matter of using multiple coils in parallel to manage the current handling requirements per coil. Other factors, like the duty cycle and dissipating heat also come into play.