HANSEN TECHNOLOGIES FROST MASTER CAT FM-71-A DEFROST CONTROLLER 115V 50/60 HZ HANSEN TECHNOLOGIES FROST MASTER CAT FM-71-A is surface mounted marine refrigeration defrost timer controller, designed for Hansen marine refrigerated cargo and cold room evaporator frost removal control system, widely fitted onboard reefers, cargo vessels and offshore cold storage units for timed hot-gas or electric defrost cycle sequencing. This marine refrigeration defrost timer controller runs on 115V, 50/60Hz AC supply, equipped with precision 7-day quartz clock and adjustable timing knobs, controls solenoid valves and fan relays to realize automatic defrost sequence, used for marine evaporator coil de-icing control. The marine refrigeration defrost timer controller integrates SPDT relay outputs, battery clock backup and NEMA4 transparent enclosure, supports optional sensor terminals for defrost initiation and termination, limits defrost duration to prevent overheating inside cold chambers. Its defrost cycle sequencing & hardware diagnostics function continuously monitors AC supply voltage, relay circuit integrity and clock operation status, detects power loss, relay fault and timer malfunction, transmits equipment fault alerts to vessel AMS alarm console. The defrost cycle sequencing & hardware diagnostics ensures automatic and reliable ice removal for marine refrigeration evaporator system. It enables reliable marine defrost controller operation under heavy vessel vibration and salt mist marine environments.

This Hansen Technologies Frost Master FM-71-A defrost controller delivers stable marine refrigeration defrost timer controller performance installed inside vessel cold room or refrigeration machinery cabinet. The defrost cycle sequencing & hardware diagnostics adopts marine-grade polycarbonate NEMA4 housing with EMC shielding against electromagnetic interference and mechanical shock. Marine refrigeration technicians rely on marine defrost controller operation to adjust defrost timing, verify relay switching action and inspect refrigeration control panel during routine maintenance. It adopts surface mounting design for straightforward spare replacement and minimal marine cold storage refrigeration system downtime. Internal circuit boards use conformal coating to protect electronic components against salt mist, condensation and temperature fluctuation. It works cooperatively with evaporator solenoid valves and fan motor assembly together with ship integrated alarm monitoring system. It is widely used as defrost timer spare hardware for Hansen marine refrigerated cargo hold and cold room evaporator automatic defrost control system maintenance and retrofit projects.