The purpose of the mechanical operations test for high-voltage air switches is to demonstrate the ability of a completely assembled switch to operate satisfactorily during its operating life expectancy. The test code has been patterned after IEC Publication 129, Specifications for Alternating Current Disconnectors (Isolators) and Earthing Switches, paragraph 48. The following specific comments noted are to assist in the evaluation of each section of the supplement stated below: 4.3 It is necessary to motor operate at minimum and maxium control voltage (as in IEC Publication 129) because operation at other than rated control voltage may produce significantly different forces and stresses from those produced during norma! voltage operatian. 4.4 IEC Publication 129 allows lubrication during the test, These proposed revisions do not. 5.3 Final judgment for acceptable completion of the mechanical nperations test (if there is any concern about contact pressure loss, voltage drop increase, or resistance increase through mechanical wear) requires satisfactory completion of a temperature rise or short-time current test.