La Marzocco Strada EP Operating Manual page 5

2. Defi nition of Models
1) General Description
The machine is built in a 3 group version and consist essentially
of 2 differnt type of boilers and is essentially composed of the
following parts:
1) Steam Boiler (produces steam and hot water)
2) 3 Coffee ("saturation") boilers
3) Brewing groups
4) Exterior Cover
5) Water pump/s
2) Description of the various parts
• Steam Boiler
The Steam Boiler consists of a cylindrical tank made of AISI
300 series stainless steel. Each unit is subject to a hydraulic
test, at a pressure of 6 bar, and has an operating pressure
of 1.3-1.5 bar. The following is a list of effective volumes and
power ratings according to the number of groups installed:
3 groups 11 liters
Covers are installed at either end of the cylindrical tank and
on one of them there is housing for the water heating element,
which allows the steam boiler to reach operating pressure within
approximately 25 minutes. Operating pressure is maintained
by temperature probe. The steam boiler has various fi ttings
used for safety devices, for supplying hot water and steam,
and for the heating element.
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 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: hydraulic test at 4.5 bar performed on ready-to-use
small boilers, at our factory;
• Coffee Boiler
The Coffee Boiler consists of a cylindrical tank made of AISI
300 series stainless steel. One each group (hot water generator
for brewing coffee).
Each unit is subject to a hydraulic test, at a pressure of 18 bar,
and has an operating pressure of 9 bar. The following is a list
of effective volume and power ratings according to the number
of groups installed:
3 groups - 3 x 1,3 liters
Covers are installed at either end of the cylindrical tank
and on one of them there is housing for the water heating
elements. The temperature of the coffee boiler is maintained
by an electronic temperature controller (PID capable) with an
accuracy of 0.2°C. The brewing groups are installed on the
boiler.
Composed of an AISI 300 series stainless steel tube. Heating
is accomplished through an immersion-type plated heating
element.
4
4000 Watts
3 x 800 Watts
V1.0
- 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 counteracting spring adjusted to 13.5 bar.
-Testing: Hydraulic test at 18 bar performed on ready-to-use
small boilers, at our factory;
• Brewing Groups
They consist of precision casting made of stainless steel. The
brewing group accepts the portafi lter used to hold the ground
coffee; the water fl ows through the brewing group, through the
portafi lter basket, through the portafi lter spout, and into the
cup(s) after brewing has been activated.
• Exterior Cover
It consists of a stainless sheet steel body. The structure has
been the object of specifi c studies to provide good aesthetics,
lower ergonometric costs for the operator and reduce the
chance of damage to a minimum.
• Sound Pressure
The weighted sound pressure level of the machine is lower
than 70dBA.
• Water Pump
There are two type of pump workink on this model of Strada:
• Rotary vane positive displacement pump set-up to operate
anytime an electric level gauge whenever the steam boiler
needs to be replenished.
• Magnetic drive gear pump to operate whenever brewing
coffee following manual or preset pressure profi le from
0 to 12 bar.
La Marzocco, S.r.l. Scarperia, Firenze, Italia