Carlo Gavazzi RM1A Zero Switching SSRs are industrial single-phase AC Solid State Relays (SSRs) with a built-in varistor. This built-in varistor secures transient protection for heavy industrial applications. These SSRs utilize Direct Copper Bonding (DCB) technology and feature self-lifting terminals, clip-on IP20 protection cover, and LED indicator. The RM1A SSRs can be used for resistive, inductive, and capacitive loads. These zero switching relays switch ON when the sinusoidal curve crosses zero and switches OFF when the current crosses zero. The RM1A SSRs offer up to 1400VP blocking voltage, >4000VACrms opto-isolation, and two input ranges including 3VDC to 32VDC and 20VAC to 280VAC/22VDC to 48VDC.