请教问题
1---PLC input normal, program running is OK, but motor not start what should we check first?
(Your PLC is fired and the motor to be controlled normally / suddenly the motor stop exhaust show we check first.)
PLC输入正常,程序运行正常,START 和STOP处有电,但电机不启动,应检查什么地方?
Ans: A. EM  button? 紧急开关
      B. In program mode? 程序
      C. Check the output voltage检查输出电压
      D. Motor breaker is off电机闸掉了
2--When you open the panel, you see 1 circuit  breaker is pitted , what do you have to do?  
当你打开一个电盘,你看到一个电路开关有麻点,你如何做?
A. replace换掉
B. Sand and put back砂纸打磨后放回去