E +l R 73.3=0.208·n2+0.42 1n2n2=15000 解得: 12,=116(A a2=6725(A) 129.3(7/mn) 223.1(r/mn) 都处于过载,不能长期运行a a Ra U E I 2 = 2 + 2 2 4 2 73.3 0.208 0. a = n + I 15000 I a2 n2 = 解得： 129.3( / min) 116( ); (1) (1) 2 2 n r I a A = = 223.1( / min) 67.25( ); ( 2) ( 2) 2 2 n r I a A = = 都处于过载， 不能长期运行