Generator teeny-tiny wires

[richwaskowitz]

I understand that a UL listed generator has been tested and approved as designed and that we need not question wiring practices we see in that equipment but holy smokes.....I just connected a 20 kW residential generator package which has a published maximum load current of 83 amps and which is fitted with a 100 amp circuit breaker and the wires between the generator and that breaker can't be bigger than #10! I know about temperature rating and all that but something just doesn't compute here for me. Can someone explain to me what I am missing?

 

[iwire]

You are not missing anything, it is all about temperature and the factory is counting on running those wires hotter than we could. They also must assume the voltage drop on such a short run is not an issue.

 

[the blur]

I've seen similar situations, and the internal machine wiring melts after a few years. Keeps them in business.

I'm rebuilding a 1800 watt heating machine rated at 120volts. It's a custom production machine, and all the internal wiring melted....... why, because 1800 watts is pushing the limit for a standard cord and plug in a regular outlet... just stupid. it should have been a 240v machine.

 

[petersonra]

You are not missing anything, it is all about temperature and the factory is counting on running those wires hotter than we could. They also must assume the voltage drop on such a short run is not an issue.

You should see the wire sizes used on aircraft. They have to use teflon insulation because they run them very hot to save on weight.

 

[iMuse97]

You should see the wire sizes used on aircraft. They have to use teflon insulation because they run them very hot to save on weight.

Don't they also run them at a much higher frequency? 400Hz?

 

[petersonra]

Don't they also run them at a much higher frequency? 400Hz?

Most of the stuff for the plane itself is 400 Hz. IIRC, the utility outlets at the seats are 60 Hz.

The frequency does not much change the wire temperature. That is mostly a function of current.