we77WE77Ex-1 115V; WE77Ex-1 115V Switch Amplifier. Key Benefits at a Glance . 1-channel; Control circuit EEx ia IIC; 115 V AC supply voltage; Reversible mode of operation; Lead breakage (LB)Switch Amplifier WE77Ex-2 230V 2-channel Control circuit EEx ia IIC 230 V AC supply voltage Reversible mode of operation Lead breakage (LB) monitoring 1 relay contact output (change