MainsPro, SW version 1.4, ©ComAp – January 2013 
MainsPro Installation and Operation Guide 
 
 
2.  Under normal conditions the Off coil is not powered and contacts are open. In case of failure, 
the contacts (12) close and the voltage is applied on the Off coil, therefore auxiliary power 
supply (e.g.UPS) is necessary to provide voltage for the Off coil.