72
ENG
User menu and unit confi guration
g0300122EN rel. 1.0 - 01.12.2021
There are also two types of activation:
• PARALLEL:
the steam request is divided equally between the burners so that steam production is the same;
• SERIES (also called
“sequential”):
if the steam request is less than 50% of the rated production, only one burner is operated.
Only if the request exceeds 50% does the other burner start.
Index
Parameter
Description
Ea10
Burner rotation
Set the burner sequence (series or parallel).
Burner rotation (in production, on ignition, no rotation)
Operating hours before rotation.
Tab. 12.o
12.4 Menu E.
S
ettings - b.
F
unctions
12.4.1
P
reheat boiler water (Installer menu)
To ensure production starts quickly, the preheat function can be enabled. In this way, even when there is no steam request,
the water temperature in the boiler is kept at a value specifi ed by the user. When production is next needed, the water is thus
warmer than ambient temperature and consequently production will start faster.
Index
Parameter
Description
Eb02
En. Preheating
Enable preheat
Set the water temperature to maintain
Set water temperature off set
Default:
Preheating disabled
Boiler water temperature set point = 70°C (176°F) Off set = 3%rH (3°C/5.4° F)
Possible settings Set point: 50 - 80°C (122 - 194°F)
Possible settings Off set: 2-20%rH (0-20°C / 32-68°F)
Tab. 12.p
The water temperature in the boiler is read by the passive NTC temperature probe in contact with the boiler. The operating
principle of the preheat function is described in the following graphs, the fi rst for control with probes, the second for control by
external signal.
Preheat with autonomous modulating control with probes
The preheating function, if active, overlaps the control diagram and modulates the power delivered to the heaters in relation to
the water temperature and the preheating set point.
Pmax
Pmin
0%
OFF
Steam_Pr
Set hy
preh
=
offset /2
hy
preh
=
offset /2
%rH
%production
Preh
%rH
hy
offset
Key
Steam_pr
Steam production
Pmax
Max production
%rH
Humidity measurement
hy
Activation hysteresis
Pmin
Min production
St
Set point
BP
Proportional band
Fig. 12.j
Preheat with control by external signal
The preheating function, if active, shifts the control diagram by a value equal to the “off set”. The preheating function modulates
the power delivered to the heaters in relation to the water temperature and the preheating set point.
Pmin
Pmax
% production
100% (signal)
Preh
ON
Preh
OFF
H
2H 2H+
offset
2H+
2offset
Preh
OFF
Start
Prod
Key
Steam_pr
Steam production
Pmax
Max production
Pmin
Min production
y
External signal
Fig. 12.k