The FRIGOBOAT 2000 TWIN series electric circuit consists of:1) 3 cables leading away from the unita. Safety cable – high pressure switch (HP) and low pressure switch (LP) b. Thermostat cable – connected to terminals ‘T’ and ‘C’ of the electronics c. Power cable – required to power the electric box 2) Electric boxa. Charter model b. Digital model 3) Power terminals – housed in the base of the unit and to which the battery must be connectedGiven the high absorption of the unit (approximately 16 Amps) we recommend that you operate thecompressors when the engine is on (so the alternator for boat charges the service battery) or when the sailboat boat is in the harbour (so the battery charger connected to the mains charges the service battery). The electric box does this automatically in different ways depending on the model. 3.7 – CHARTER CONTROL BOX FOR BOAT (see diagram R1416) 3.8 – DIGITAL CONTROL BOX (see diagram R1418) IMPORTANT NOTE: This model exists in 12V version This lets the refrigerator for boats unit function (and therefore produce and accumulate cold temperatures), but only whenthe engine is switched on. This is due to the engine start-up contact (CA) connected to marine terminal no.1. This way you are sure to have the service battery charged when the compressor and pump of the refrigerator unit are running. If you do not have a CA contact, you can make the FRIGOBOAT 2000 TWIN function with the Charter box by inserting a bridge between terminals 0 and 1, thus making the functioning of the engine independent from the refrigeration unit for boats. WARNING: With a bridge between terminals 1 and 0, the refrigerator system can work even when the services battery is not undercharged, but there is a high risk of depleting it entirely. Therefore if you do NOT have the CA contact, we strongly recommend that you purchase the ‘Digital’ electric box. Calibration Functioning principles This model can function automatically with 12V and 24V power supply.The available voltage is read (shown on the display in the centre of the box) and the charge status of the battery is determined. Two voltages are set, called ‘CUT IN’ (high threshold) and ‘CUT OUT’ (low threshold). Thus the electronics system knows when it must allow or stop the refrigerating unit from functioning in order to save battery power. The CUT IN voltage is the threshold above which the unit is allowed to function, as the battery is charging from the alternator or battery charger. For this reason, the value of the ‘V cut in’ must be set so that V cut in < V battery when the battery is undercharged. The CUT OUT voltage is the minimum threshold under which the refrigerating unit cannot function, in order to avoid depleting the battery. Therefore the ‘V cut out’ must be set so that V cut out = V battery when the battery is NOT undercharged. With these settings, the refrigerating unit will only work when the service battery is powered by the alternator or battery charger, therefore only when the engine is running or the boat is connected to the power mains of the harbour or from a generator. Calibration, in this sense, means entering the power voltage thresholds – VHI (V cut-in) and VLO (V cut-out)which determine the system’s functioning. Press the CAL button on the left of the display. The words SET LO will appear, followed by the value of the RV2 trimmer (at the bottom right of the display). Set the VLO value and press CAL. You will see the word LOAD followed by SET HI. Now rotate the RV1 trimmer (top right) and set the VHI value. 6