English
13
GB/5 - FB/80
www.lamarzocco.com
V1.3
8. History and Use of the “La Marzocco” Coffee Machines
another, the special manifold and fastening system of the
groups to the boiler as well as the electronic temperature
control, have allowed us to:
1)
achieve an excellent thermal equilibrium between the
brewing groups, both at times of discontinuous operation and
during peak times;
2)
be able to control the temperature of the water running
through the brewing groups, independently of the “pressure”
and the level in the small steam boiler, and therefore to optimize
the water temperature itself in order to obtain the best possible
coffee with whatever coffee mixes are available commercially;
3)
save on electrical energy by more than 30%, in many cases,
when compared to other machines.
The “GB/5” series machines are produced in the 2, 3 and 4
group versions.
CONTROL SYSTEMS AND SAFETY DEVICES BUILT INTO
“LA MARZOCCO” COFFEE MACHINES
All models are equipped with:
- automatic level regulator;
- automatic pressure regulator;
- automatic temperature regulator;
- safety devices
spring operated safety valve;
manual reset thermostats.
In all models, coffee is brewed by opening a solenoid valve,
one for each group. For the “EE” model, the quantity of coffee
brewed is regulated manually by the operator through a switch,
while in the “AV” model the quantity is regulated automatically
in 4 different doses, which may be programmed at will for each
brewing group. This last model is equipped with control panels,
one located above each group, with 4 buttons which may be
programmed in such a way that by pressing the 1
st
button you
get 1 regular coffee, pressing the 2
nd
one you get one weak
coffee (tall), pressing the 3
rd
you get 2 regular coffees and by
pressing the 4
th
one you get 2 weak coffees. The fifth button,
which has a spiral sign, allows continuous brewing operation
which can be interrupted by pressing the very same button again.
CONSTRUCTION DETAILS
They consist essentially of 2 small boilers, of which:
1) Coffee Boiler (hot water generator for brewing coffee)
2) Steam Boiler (steam generator for producing steam and hot
water for making tea and other hot drinks)
1) Description of the Coffee Boiler (C.C.)
Composed of an AISI 300 series stainless steel tube.
Heating is accomplished through an immersion-type plated
heating element.
-Operating temperature 95
°
C (adjustable), controlled
automatically by an electronic temperature controller with an
accuracy of 0.2
°
C. Operating pressure of 9 bar, developed
mechanically by a special positive-displacement pump which
is activated automatically every time coffee is brewed.
-Pressure is displayed through a pressure gauge with a scale
from 0 to 15 bar.
-Safety device, based on an expansion type mechanical valve,
with counter-acting spring adjusted to 12 bar.
-Testing:
-Hydraulic test at 18 bar performed on the ready-to-use small
boilers, at our factory;
2) Description of the Steam Boiler (C.V.)
Composed of AISI 300 series stainless steel tube.
Heating is accomplished through an immersion-type plated
heating element.
-Operating pressure of 1.3-1.5 bar, controlled automatically
through a pressure switch or a temperature probe, adjusted so
as to open the heating element supply circuit at 1.5 bar and
close it at 1.3 bar.
-The pressure is displayed by means of a pressure gauge with
a scale of 0 to 2 bar.
-Safety device, based on an expansion type mechanical valve,
with counter-acting spring adjusted to 1.8 bar.
-Testing:
a) hydraulic test at 4.5 bar performed on the ready-to-use small
boilers, at our factory;
Capacity and Power Ratings
1) C.C.
- 2 groups
3.4 litres
1400 Watts
- 3 groups
5.0 litres
1600 or 1900-(HI-Power) Watts
- 4 groups
2x3.4 litres
2x1400 Watts
2) C.V.
- 2 groups 7 litres 2000 or 3000-(HI-Power) Watts
- 3 groups 11 litres 3000 or 4000-(HI-Power) Watts
- 4 groups 14.5 litres 3000/3800 or 5000-(HI-Power)Watts
Operators Manual - ENG - V 1.3.pmd
30/10/2006, 14.34
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