Power failure alarm If there is no power from the utility, the corresponding buzzer is activated and emits an alternating sound (like a low-frequency Bip-bip). The corresponding LED lights up and the buzzer can be muted. There is 24 VDC power fed through a backup battery with a recharge circuit that can provide enough power in case the utility is not providing any. Discharged battery warning A LED indicated low battery status. CO2 or LN2 Backup system (optional) If there is a failure in the cooling system (compressor failure or other) at a definite and configurable threshold, (-55 °C), the cryogenic gas (CO2 or LN2) backup system is activated. The ON OFF command, with programmable hysteresis and delay, controls a cryogenic gas valve for CO2 or LN2. The (Backup) LED remains lit for a programmable period counted from the last time the valve is opened. The gas is injected gradually and modularly in order to optimise gas consumption. In case a door is opened the valve command is disabled. All alarms and the intervention notice for the LN2 backup system can be managed remotely by means of a connector on the device; this allows users to be able to send alarm signals to other places or a phone exchange to send a call and/or SMS. The K40......HSL line represents the ?45°C/-50°C version of the HS at ?85°C