Bunn ES1A service manual Features, BUNN Espress, Model ES 1A, Boiler, Electrical pump

BUNN Espress™

FEATURES

Model ES•1A™

Hot water rinse dispensing tube and steam dispensing tube

The ES•1A™ is equipped with a hot water rinse dispensing tube and a steam dispensing tube. They are operated by moving the levers located at the bottom of the machine from to side-to-side; they can be placed in a continuously open position if required. The outlet tubes can also be rotated.

STEAM

HOT WATER RINSE

P-157

Boiler

The boiler is made of copper plating, 1.5 mm thick; it operates under a pressure between 1.1 to 1.3 bar (16-18.8 psi). This is measured by means of a pressure gauge with a scale from 0 to 2 bar (0-29 psi). The safety valve assures that boiler pressure never exceeds the safety limits; it automatically discharges steam when pressure inside the boiler exceeds 1.8 bar (26.1 psi). The water heating element is an electric resistance unit controlled by a pressure switch. This switch automatically regulates the pressure of steam in the boiler. The pressure switch will automatically shut off the heater when necessary.

Electrical pump

The electric pump incorporated in the machine is required to obtain optimum water pressure of 9 bar (130 psi) for espresso extraction. If water pressure from the tap exceeds 5 bar (73 psi), a pressure reducer should be installed to avoid damaging the machine. If a pressure reducer is required, it should be installed in the water inlet pipe just before the water conditioner or electric-pump.

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