Strebel S-CBX 105, Руководство по установке, эксплуатации и техническому обслуживанию

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15.2.3 C
ASCADE
– D
OMESTIC
H
OT
W
ATER
S
ETTINGS
In the installer DHW menu of the managing boiler control the DHW_Mode should be set.
Available DHW modes in cascade are mode 1 = sensor or 2 = Control Thermostat (see chapter 12.8 "Demand for
Domestic Hot Water").
Dependent Boiler
In case a boiler is set as dependent (parameter 184: "Burner address") the DHW setpoint is always provided by
the managing boiler, the internal control of the setpoint functions are disabled.
Managing Boiler
If there is a request for a “Store Warm Hold” for the tank and no central heating request the managing boiler is
going to burn for the DHW tank. This (the heating of the DHW tank) is interrupted when there comes a central
heating request and the managing boiler and cascade are burning for the central heating system.
15.2.4 C
ASCADE
– DHW
PRIORITY
The boiler cascade system has multiple options for priority and parallel DHW and heating.
The following levels of priority are configurable (and possible):
Priority level Description
0) Switch Priority When both CH and DHW demand have to be served, the priority it is given to the DHW demand
for a given interval (indicated with parameter Minute_Switch_Priority).
As soon as the interval has expired the priority switches to CH demand.
The interval time will be reloaded, and priority will switch again after the interval is over.
1) CH The priority is permanently given to CH Demand
2) DHW The priority is permanently given to DHW Demand
Relevant variables
Specific Parameters Level (Default) Value Range
DHW Priority
Both, CH or DHW priority, Parallel
2: Installer 2 0, 1, 2
DHW Max Priority Timer
Interval time for switching the priority
2: Installer 60 min. 1..60 min.
15.2.5 C
ASCADE
– S
TART
/
STOP SEQUENCE
The managing boiler sends the calculated Cascade_Setpoint to the dependent boilers. The power of the boilers
is PID controlled based on the Calculated_Setpoint and T_Supply. Depending on the temperature difference
between T_System and Cascade_Setpoint (CH or DHW) the dependent boilers will start or stop using different
algorithms.
Quick Starting and Stopping Boilers
When there is a big difference between the T_System and the Cascade_Setpoint the call for a start or stop of the
next or last depending is done quicker.
• Quick Starting Burners : If the T_System is Hyst_Down_Quick_Start degrees below the Cascade_Setpoint
the burners are started at intervals of Quick_Start_Next_Depending_Delay , for
example 30 sec.