To be more precise, I will show you a table with information about cable resistance, current capacity and voltaje drop produced at full load.
Your generator, is 7000W peak and 5500 running at 220V.
In this calculation we will asume 5500W continuous at 220V. If this genset has 110 220 outlets it meas that has two legs,110V each one, with a máximum current of: 5500W/ 220V= 25 Amp.
This current is the same that circulates in both windings (legs). Each one with 110V at 25A= 2750W , both circuits power: 2750W x 2 =5500W.
To select a cable there are 3 basic elements to consider:
1.- Current capacity, how many amps can be carried at a max temperature
2.- Max voltaje drop, product of the current circulating multiplied by the total cable resistance. This resistance depends from the cable material (normally copper), total lenght of both wires and the effective wire section or area. More lenght, more voltage drop, more diameter, less drop.
3.- Insulation material, depends of the enviroment: Temperature, humidity, mechanical stress, physical protection, etc. The most common and useful for this application: Type TW ( may be any other applicable)
Please see the attached table. I couldn't insert here.
With a AWG 10 you cover all your needs: 3.75 V voltaje drop and 30 Amp capacity for full load operation at 5500W. For very short periods at 7000 W will carrie 32 A and a voltage drop of 4.8 V at the cable end point.
Hope this help you and clarify your doubts.
Last edited by Osviur; 07-11-2019 at 08:53 PM.