Measurement Values Supply Temperature Sensor; Measurement Values Outdoor Temperature Sensor; System Integration Of The Icm; Principles Of Cascade Control - Bosch ICM Notice D'installation

6 | Details about the ICM module
2.6.4 Measurement values supply temperature
sensor
°F ( °C) Ω
VF
68 (20) 14772
79 (26) 11500
90 (32) 9043
100 (38) 7174
111 (44) 5730
122 (50) 4608
Table 3

Measurement values supply temperature sensor

2.6.5 Measurement values outdoor temperature
sensor
°F ( °C) Ω
AF
– 4 ( – 20) 2392
3 ( – 16) 2088
10 ( – 12) 1811
18 ( – 8) 1562
25 ( – 4) 1342
32 (± 0) 1149
Table 4 Measurement values outdoor temperature
sensor
2.7

System integration of the ICM

2.7.1

Principles of cascade control

When the boiler generates a heat demand (
system versions 1, 2, 3, and 4), initially one boiler is
started and, if required, its heat output is raised to its
maximum nominal power. Only then will another boiler
be started.
If excessive heat is being generated, boilers are
modulated down one by one in sequence without delay
to their respective minimum nominal power, and then
shut down until heat demand and generation match.
With system version 4 all appliances are shut down
simultaneously.
The ICM module automatically determines the sequence
in which the boilers are controlled. The ICM module
rotates boilers to achieve equal run time and wear. While
taking into account heating and DHW. This increases the
boiler service life. If the power supply to the ICM module
is interrupted, the hours run meters in the ICM module
are reset to zero.
6 720 643 835 (2011/06)
°F ( °C) Ω
VF
133 (56) 3723
144 (62) 3032
154 (68) 2488
165 (74) 2053
176 (80) 1704
187 (86) 1421
°F ( °C) Ω
AF
39 (4) 984
46 (8) 842
53 (12) 720
61 (16) 616
68 (20) 528
75 (24) 454
table 5,
As soon as a boiler is unable to start (DHW heating for a
directly-connected DHW tank, boiler fault,
communication fault with ICM module), another boiler
will be started automatically to cover the heat demand.
2.7.2

Heating controls for ICM cascade systems

The ICM modules stage the boilers based on the heat
demand calculated. The heat demand is communicated
to the ICM in 4 different ways (
J, page 10), ( table 5).
NOTE:
B if multiple heat demands are present, the
highest water temperature is being used.
One ICM module can control up to 4 boilers. By
connecting up to 4 ICM modules, up to 16 boilers can be
linked to form a single cascade (
In this case, one ICM module controls the cascade
(ICM master).
Depending on the heating system controls used, a
cascade system with up to 4 or up to 16 boilers can be
created. The maximum number of boilers that can be
connected and the number of ICM modules required for
the different systems are shown in table 5, page 8.
NOTE:
B The different system versions require the
connection of certain accessories (supply
temperature sensors, outdoor
temperature sensors, heating pumps,
and heating system controls) (
page 8).
The ICM module controls the entire boiler loop (primary
loop including the low loss header). All other heating
system components (secondary side of the low loss
header, such as the heating zones, hot water tank) can
be controlled by the Hydronic 3 using zone modules. See
the product documentation for further details. In all
other case the heating system is controlled by third
party components. See the product documentation for
further details.
Boilers of any output can be part of a cascade.
fig. 6, terminals H, I or
fig. 6, page 10).
table 5,