GENERAL
21
ter C609 (P_ACC). After the second module comes on,
the overall output requested is divided between the two
modules.
When the two modules that are on reach the output of
the parameter C609 (P_ACC), a third module is ignited
and the overall output is divided between three and so
on until all the burners are on.
When each module is switched on, the calculation of the
PID is paused, until all the modules have reached the
common output setpoint, limited by F_SET (C607) and
by V_SET (C608).
0,25
1
2
3
4
5
6
7
8
0,5
0,75
1
Moduli
P_ACC
Modules
When all the modules making up the boiler are on, the
regulator sends an output request (P_SET) to the mod-
ules that is the same for them all until the maximum
output is reached.
If the overall output requested by the regulator dimin-
ishes, then the output requests for the modules diminish
in a proportional and uniform way (as if it were a single
boiler) up to a switching off output percentage that is set
with parameter C612.
From then on the modules are switched off backwards
as soon as the switching off output is reached, accord-
ing to the «first on - last off» logic and the overall output
requested is divided proportionally among the ones left
on.
1
2
3
4
5
6
7
8
1
2
Moduli
P_SPEG
Modules
The switching off phase concludes when the leader
burner is off. This switches off according to the logic
expressed in figure 1.
NB.
1 - If the difference between the setpoint temperature
and the temperature of the delivery collector probe is
greater than the parameter C616 (Delta_T for ignition
of all the modules with strategy B), then all the mod-
ules come on at the same time (automatic passage
to management as per strategy A) to speed up the
implementation of the system (rapid implementation).
2 - With the aim of reducing the number of inactive igni-
tions you can use the parameter H611 which sets the
minimum time that has to pass between a burner's
switching off and its restarting.
Similarly with parameter H610 the minimum time
between ignition and switching off is limited (start-
stop limitation).
3 - The first module to come on in strategy B is the
«Leader» module; the modules then come on in
ascending order of address with the largest number
of operating hours, and so on.
When the leader module has reached a number of
ignition hours equal to the parameter C618 (valid only
for strategy B), the number of its operating hours is
reset and the new leader is identified, which will that
one with a greater address with the most number of
operating hours. (rotation of burners).
4 - A module is active if it is connected and has no faults
DOMESTIC HOT WATER PRODUCTION
The domestic hot water request comes via a temperature
probe or a thermostat. The selection of the type is made
with parameter C559:
- with C559=0 boiler only with heating
- with C559=1 storage cylinder probe
- with C559=2 storage cylinder thermostat.
At the end of each request there is a post-circulation con-
trol, namely the domestic hot water circulator is started
for the time set in parameter H544.
With a thermostat, the request occurs when the contact
is closed and ends when the contact re-opens.
With a domestic hot water probe, the request occurs
when the temperature displayed drops below the value
requested for a quantity equal to parameter H617. The
request ceases if the temperature measured by the
probe exceeds the setpoint of a value in parameter
H617.
The domestic hot water temperature has a maximum that
is expressed by parameter C513.
Summary of Contents for 20020843
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