23
2.4.4 - DOMESTIC HOT WATER (DHW)
MODE OPERATION
Each boiler is equipped with an AM-4
board, necessary to control a D.H.W
tank and to receive a 0 - 10V signal from
an outer compensator (se fig. 11). If there
is a heat request, the MBD can control
either a storage tank loading pump or a
3-way diverting valve. So the boiler will
ignite and operate according to what
previously described. The global flow
water temperature, set as standard 20
K higher than the requested DHW tem-
perature, is modulated as well. By us-
ing dip-switches, it is possible to limit
the boiler output when working in D.H.W
mode, in order to avoid overheat when
the DHW storage tank absorbed output
is less than the boiler produced one.
DHW production has always priority on
heating. Some examples about hydrau-
lic and electric connections of a hot
water storage tank are shown in the fig-
ures 6.1 - 6.2 - 6.4 .
2.5 - OPERATION IN CASE
OF TECHNICAL INTER-
VENTION
For after sale service and test reasons,
any single thermal element or all simul-
taneously can be kept operating at full
or reduced load. In this way the CO
2
lev-
el can be checked and, if necessary, ad-
justed at full or reduced load (for any sin-
gle thermal element or for all simultane-
ously).
X1= diverting valve or storage tank
loading pump
X2= outer compensator / D.H.W. tank
NTC
X7= to the MBD by flat cable
Fig 11
AM-4
0-10 V
DHW
Tank
NTC
X1
X2
DIPSWITCH 2
DIPSWITCH 1
X7
Flue
Temp.
IN THE MODULEX BOILERS WITH AN
OUTPUT HIGHER THAN 360 KW
In order to guarantee the best D.H.W.
production the dip-switches present
configuration allows a maximum avai-
lability up to 360 kW.
For example:
If we combine a 90 kW storage tank to a
Modulex 360, setting the dip-switch 1 to
“OFF “ and the dip-switch 2 to “OFF”, so
as to adjust the functioning of the num-
ber of modules on the basis of the stora-
ge tank's requests (one module will func-
tion).
If we combine a 180 kW storage tank to
a Modulex 360, setting the dip-switch 1
to “OFF “ and the dip-switch 2 to “ON”,
two modules will function.
If we combine a 270 kW storage tank to
a Modulex 360, setting the dip-switch 1
to “ON “ and the dip-switch 2 to “OFF”,
three modules will function.
If we combine a 360 kW storage tank to
a Modulex 360, setting the dip-switch 1
to “ON “ and the dip-switch 2 to “ON”, four
modules will function.
Thanks to this option the search for fail-
ures on each thermal element will re-
sult easier.
CONFIGURATION
Just one module is
ignited (90 kW)
Two modules are
ignited (180 kW)
Three modules are
ignited (270 kW)
Four modules are
ignited (360 kW)
DIPSWITCH CURSOR POSITION
REGULATION
360 kW
270 kW
180 kW
90 kW
2 1
O
F
F
2 1
O
F
F
2 1
O
F
F
2 1
O
F
F
