The model CA5000 freezer back-up alarm system from Hampshire Controls Corporation offers user-programmable alarm & control set points & alarm delay times. Parameters are stored in non-volatile memory and are maintained when power is lost. When a malfunction occurs and the freezer warms above the user-defined set point, a user-defined amount of LN2 is injected into the freezer. Other features include:
- An internal battery with charger, which keeps the alarm running for at least 24 hours after a power outage.
- "BAT" indicator that warns of a disconnected or low backup battery condition.
- Backup time of at least 48 hours on one 65 liter cylinder of LN2 at –65°C set point.
- Visible and audible indicators for system status.
- Multiple programmable alarms available to minimize nuisance or false alarms.
- Relay output for central alarm systems or automatic dialers.
- A door safety interlock switch that prevents LN2 injection while the freezer is being accessed.
