The Zelio RPM series Electromechanical Plug-in Power Relay comprises of protection modules or 1 timer module. All these modules are common to all sockets except for the timer module, which can be used only on 3 or 4-pole sockets. Removable lock-down door enabling forced maintaining of the contacts for test sequences or maintenance purposes. During operation, this lock-down door must always be in the closed position. It offers four notches for rail mounting adapter or panel mounting adapter with fixing lugs. It has 15A relay with 1/2/3/4 C/O contacts and the sockets with mixed contact terminals.