IEC TR 60943:1998

Is intended for guidance in estimating the permissible values for temperature and temperature rise of component parts of electrical equipment carrying current under steady state conditions. The present report is intended to supply: - general data on the structure of electric contacts and the calculation of their ohmic resistance; - the basic ageing mechanisms of contacts; - the calculation of the temperature rise of contacts and connection terminals; - the maximum 'permissible' temperature and temperature rise for various components, in particular the contacts, the connection terminals and the conductors connected to them; - the general procedure to be followed by product committees for specifying the permissible temperature and temperature rise.