Chapter 3 Functional descriptions
52 SMSO-2-02.03- 15.07.03
3.2.16 Instant heater
The coffee water is prepared in the instant heater. The ex-
tremely high heat rating means that heating times are very
short. Thus a certain amount of hot water is always available
ready to serve a product and it can be topped up very quickly.
Over-temperature protection
A three level safety concept protects the instant heater and the
steam generator against overheating and bursting.
The first level is the temperature sensor. It switches the
heater on and off according to the temperature of the
water.
The second level is the safety thermostat. If the surface
temperature of an instant heater / steam generator
reaches 155
o
C the safety thermostat disconnects the
heater circuit.
The third level of safety is the safety valve. Any
overpressure is relieved off.
Function
Instant heaters are made from stainless steel. The heating
and the threaded connectors to the feed pipe, the hot water
pipe and to the temperature sensor are welded at the top.
Every instant heater is subjected to a comprehensive quality
control procedure immediately after it has been manufactured.
The test certificate is a component of the instant heater and
must be kept available throughout the entire service life of
such devices. All checks and service work must be entered
onto the test certificate.
A heating spiral is accommodated in the lower third of the
container. It is attached to the power relay via two safety
thermostats. One of these safety thermostats is located be-
tween the two flanges on the heater spiral. The second is
located above the heater spiral and ensures a reliable tem-
perature transfer even when the instant heater has heavy
calcium deposits.
The feed pipe is closed at the end, the water flows through
four small bore holes in the side, at a downward slant, against
the wall of the container, thus mixing efficiently with the hot
water. By obtaining an improved mixing of water only a mini-
mal difference in temperature occurs between individual prod-
uct servings.
The temperature sensor is not positioned in the inflowing cold
water and thus does not produce any incorrect measure-
ments.
Control of the heater
Machine without booster: The heater control system de-
pends on the various operating conditions and the time be-
tween individual product servings (see section on “Tempera-
ture control system).
Machine with booster: The heating time for the instant
heater is controlled very much by the relevant mains voltage.
For this reason the actual mains voltage must be measured
at the place of assembly of the machine. The closest voltage
value should then be set in the programming (selectable in 10-
volt steps, e.g. 220 V, 230 V etc.).
Instant heater
1 Container (stainless steel)
2 Heater
3 Safety thermostat
4 Feed pipe
5 Water
6 Brewing tube
7 Temperature sensor
FUNCTIONAL SAFETY
Instant heaters are pressure containers and
are checked as a complete unit after the
manufacturing process. Mechanical or
chemical cleaning and decalcification can
weaken individual components and welded
seams. This gives rise to the danger of
bursts or leaks. Instant heaters should
therefore never be decalcified either me-
chanically or chemically.
Technical data
Volume: 0.8 l
Operating pressure: 7.5 bar / max 12 bar
Heater rating: 3.0 kW
Voltage/current 230 V AC, 13A
Winding resistance: 15.1 Ω (230 V; at 20 °C)
Operating temperature coffee 86 °C - 102 °C
Operating temperature tea 90-98 °C
Max. over-temperature: 192 °C
Heating time: 10 ° --> 86 ° approx.:
<2Min.
Drawing symbol
Illustration
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