Cascade - Power Balance Mode (Rev. 4.0.905.15906) - Bosch SSB1000 SA Manual

Relevant variables
Specific Parameters Level
Delay_ Period_Start_Next_
Burner
2: Installer
[min]
Start Delay Time
Delay_ Period_Stop_Last_
Burner
2: Installer
[min]
Stop Delay Time
Quick_Delay_ Period_
Start_Next_Burner
2: Installer
[sec]
Quick Start Interval
Quick_Delay_ Period_
Stop_Last_Burner
2: Installer
[sec]
Quick Stop Interval
Hyst_Down_Start_Burner
2: Installer
[°C/°F]
Start Burner Diff
Hyst_Up_Stop_Burner
2: Installer
[°C/°F]
Stop Burner Diff
Hyst_Up_Stop_All
[°C/°F]
2: Installer
Stop Burner Diff
Hyst_Down_Quick_Start
2: Installer
[°C/°F]
Start Burner Diff in short time
Hyst_Up_Quick_Stop
[°C/°F]
2: Installer
Stop Burner Diff in short time
3 .3 .5 Cascade – power balance mode (Rev . 4 .0 .905 .15906)
Two different power control modes can be selected to operate the
cascade system.
• Power mode 0:
Power control disabled, each burner modulates based on the system
setpoint.
• Power mode 1:
Power control algorithm to have a minimum amount of boilers/burners
active.
• Power mode 2:
Power control algorithm to have a maximum amount of boilers/
burners active.
• Power mode 3:
Power control algorithm to have a balanced amount of boilers/burners
active.
3 . 3 . 5 . 1 Power mode 1 - Minimum burners on (Rev . 4 . 0 . 9 05 . 1 5906)
Power Mode 1 guarantees to have as minimum as possible dependent
ON in order to reach the T_System .
The modulation of most boilers/burners is forced to 100%, and the last 2
boilers/burners are PID controlled by the setpoint ( Cascade_Setpoint )
from the managing burner in relation to the system temperature ( T_
System ).
The last 2 boilers/burners are modulating to make sure that the power
can be adapted to the system temperature without continuous cycling of
the last burner(s).
Below is a picture that shows an example with 4 boilers/burners.
SSB
(Default)
Settable
Value
°C °F °C °F
3
1..15
(min)
3
1..15
(min)
30
5..300
(sec)
30
5..300
(sec)
5 9 0..20 0..36
5 9 0..20 0..36
30 54 30 54
10 18 0..20 0..36
10 18 0..20 0..36
Burner Startup
The next burner is started under the following conditions:
• At least one PID controlled depending is operating at a power [%] >
Start_Rate_Next_Burner [%].
The managing burner forces another burner to 100% power and waits
for 3 min. ( Delay_Period_Start_Next_Dependent , settable)
before another burner can be started.
Burner shut down
The last started burner will be stopped under the following conditions:
• All PID controlled depending in burn state Power [%] < Stop_Rate_
Last_Burner [%]. The managing burner releases another burner
for PID control and waits for 3 min.( Delay_Period_Stop_Next_
Dependent , settable) before another burner can be stopped.
Relevant variables
Specific Parameters Level
Power_Mode 2: Installer
Start_Rate_Next_Burner
[%]
Threshold rate before start the
2: Installer
next Burner. Condition: at least 1
depending in burn state power [%] >
Start_Rate_Next_Burner [%]
Stop_Rate_Last_Burner
[%]
Threshold rate before start the next
2: Installer
Burner. Condition: all depending in
burn state Power [%] < Stop_Rate_
Next_Burner [%]
Delay_ Period_Start_Next_
Burner
[min]
2: Installer
When the timeout is over the last
dependent can be started
Delay_ Period_Stop_Last_
Burner
[min]
2: Installer
When the timeout is over the last
Burner can be stopped
Hyst_Up_Stop_Burner
Hysterese to stop Burner. Condition:
2: Installer
T_System above Header_Setpoint
plus Hyst_Up_Stop_ Burner
Hyst_ Down_Start_Burner
[sec]
2: Installer
Hysterese to stop Burner. Condition:
T_System below Header_Setpoint
plus Hyst_Up_Stop_Burner
BURNERS cascade | 15
(Default)
Range
Value
°C °F °C °F
3 0..3
80 1..100
25 1..100
3 1..15
3 1..15
5 9 0..20 0..36
5 9 0..20 0..36
6720892984 (2019/02) US