أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
Yes , definitely it is normal
any switch operates the machine ,it must be normal open,because when the power line is cutting the machine is not work and no dangerous will appear, and any switch stopes the machine ,it must be normal close because when there is cut in power line the machine will stop to prevent any acciedent
