TRANSTECTOR's 1101-1154 120/240 V single phase silicon avalanche suppression diode (SASD) and metal oxide varistor (MOV). Compact DIN rail surge protection assembly used to protect 120/240 VAC single phase three-wire power systems from over-voltage caused by transient surges. The MCP 120T-30A1-G features replaceable SASD primary and MOV backup suppression modules coupled with VSP surge rated fuses.