Douwe Egberts Cafitesse 700, Back Office Manual

Page: 159 / 265

July 2004
5A - 17
Functions - water system
Function: Boiler
• Container:
Container made of plastic
Capacity: 13.5 l (3.6 gal)
• Heating elements:
The water in the boiler is heated by up to
3 heating elements.
• Electronic dry boil safety device including
electrodes:
Missing water is detected by the electrodes.
The electric current in the safety circuit is
interrupted by a relay. The protective relay
interrupts the electric connections to the
heating elements.
• The dry boil safety device is automatically
reset when the corresponding filling level in
the boiler is reached.
Peak output (maximum removal):
With internal elbow and with the temperature
sensor in upper position:
•
4 pots (à 1,500 ml 6.0 l/1.58 US gal) can
be delivered directly after one another.
without internal elbow and with the temperature
sensor in lower position:
•
1 2/3 pots (à 1,500 ml 2.5 l/0.66 US gal)
can be delivered directly after one another.
Specification:
initial temperature boiler 94
°
C (201
°
F)
(homogeneous) and at least still 80
°
C (176
°
F) (mixed temperature) in the last pot.
• This output is achieved by the special water
supply system of the boiler: The inlet zone
(1) is connected to the heating zone (2)
merely at the bottom of the boiler. This
prevents any successive cold water from
mixing with the hot water in the top part of
the heating zone. Mixing the cold and hot
water would result in a cooling process and
therefore in reduced peak output. (Fig. 1)
A.3 Functional descriptions
A.3.1 Functions
Fig. 1
2
1
Function: Boil over sensor
• The boil over sensor (bimetal temperature
limiter) is installed above the overflow open-
ing. (See chapter A.2)
Activation temperature 75
°
C (176
°
F)
±
5K
• If, in case of malfunction, the temperature
regulating system does not switch off the
heating system in time, the water starts to
boil and steam develops.
• This steam then heats the boil over sensor.
When boiling-over occurs inside the housing,
the bimetal switch interrupts the flow of
electric current in the safety circuit, resulting
in the protective relay interrupting the electric
connections to the heating elements.
• Depending on the preset heating capacity,
the boil over sensor switches off the heating
system within 10 to 30 sec. following the first
indications of boiling.
• The switch in the boil over sensor must then
be reset manually using the red pin.
Cafitesse 700 - Functions - water system