Helset was born in Nannestad. The son of Peder Helset and Ingeborg Kristiane Skjegstad, he grew up in Romerike. He married Nini Eugenie Hansen in 1920.[1]
Helset served as Head of the Norwegian Army from 1946 to 1948, when he resigned after a conflict with the government on defense policy. After his resignation he served as head of the district of Southern Norway, with the rank of Major General. He served as commander of the Fredriksten fortress from 1951 to 1953. He was a leader of the Norwegian Confederation of Sports from 1946 to 1948. In 1947 he was decorated Commander with Star of the Order of St. Olav. He was a Commander of the French Légion d'honneur and Commander of the Swedish Order of the Sword.[1][5]