MNP37M03GBV00 Date: 24-11 Rev. 0
Page 24 of 79
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Timer system protection.
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Water intake solenoid valve. When the machine is filled for the first time, if the
air-break does not fill up within 10 minutes, the valve puts the machine out of
service. If the machine is working normally, there is a 2-minute period for the air-
break to reach its maximum level, after which the machine will be put out of
service (if not connected to water mains, it controls the water intake pump).
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The machine is not operational at temperatures under 10 °C below programmed
working temperature.
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If after consecutive sales totalling 200 cc of water, the air-break water level does
not diminish so the water intake solenoid valve begins to work (the air-break
floater is stuck) the machine will indicate a fault condition.
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The movements of the rotating arm, cup dispensing and cup storage assembly
rotation are programmed so that 5 faulty consecutive movements in any of the
CC motors will result in a fault condition.
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Water network pressure protection system. At the outlet of the pressure pump
that feeds the pressure boiler there is a one-way valve that prevents the water
from going into the pump against normal flow. There is also a safety valve that
prevents overpressure in the water system. This valve is set at 11 bar, so should
any of the solenoid valves become obstructed or fail, the water circuit will not be
subjected to excess pressure.
Should the machine show a fault condition because of any of the above
faults, there is an automatic reset every hour to check whether the problem has
been solved (the display shows the message “Self-check”)
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Overheat protection systems in the motors.
All 220-V motors in the machine, that is, those that carry out the dosage of
soluble products and sugar and the beater motors, have their own protection
system to prevent overheating.
The vibrating pumps used to move the water from the water circuit to the
pressure boiler are equipped with an overheating protector set at 90 °C.
6.2. - Water circuit.
The water circuit of machines which dispense soluble products and espresso
coffee, is shown in figure 6.02.
