I had lot of questions from beginners, how to switch on the load using only "Normal-Open" (NO) button. 
<ul><li>-So, it is very simple. You're pushing the button SB2, current starts to gain through contactor KM.
<ul><li>There appears circuit: hot wire - terminal - SB1 - SB2 and paralel doubled on NO pair (13-14) at relay - contactor KM - zero wire. To switch off, you should push SB1 button.</li></ul></li></ul>
<a href="//commons.wikimedia.org/wiki/User:Dmitry_G" title="User:Dmitry G">Dmitry G</a>
<span class="int-own-work" lang="en">Own work</span>