I misspoke (wrote)? 10-3 would be three conductor with ground. 10-2 is sufficient. Please check this out from Vince Galbo @ MSB.....
http://www.msbtechnology.com/faq/how-to-wire-your-house-for-good-power/
http://www.msbtechnology.com/faq/how-to-wire-your-house-for-good-power/