What the key rating means
The G6AU-274P-ST-US DC5: The 5 VDC coil rating sets the pick-up voltage for this relay. In a 5 V logic or PLC output circuit, the coil will energise reliably at nominal; verify your driver can source the coil current (typically around 30–40 mA for this class) without exceeding the output's sink rating.
Signal relays like this one switch low-power signals — think PLC digital outputs, sensor interposing, or small indicator loads — on a PCB inside a control panel. They are not rated for motor or high-current power switching; that is the contactor's job.