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E2
PROM ADDRESS SELECTION THROUGH E
This setting can be changed on the boiler control.
Boiler address
0 (default
1
2
3
4
↓
16
Table 14.1
C
– H
ASCADE
When a boiler is set as Managing (Address = 1), the controller of this boiler will drive the cascade. The CH mode
of this managing boiler applies to all other boilers. It is only required to set the CH mode on the managing boiler.
•
The outdoor temperature sensor connected to the managing boiler will be the outdoor sensor for the cascade
operation
•
The system sensor (T_System) connected to the managing boiler will be the control sensor for the cascade
supply temperature.
•
The (modulating) thermostat connected to the managing boiler will be the CH heat demand input for the
cascade system.
Based on the system temperature (T_System) and the requested Cascade_Setpoint the managing boiler
calculates a required boiler setpoint, to achieve the requested Cascade_Setpoint.
The managing boiler provides the calculated setpoint to all dependent boilers. The modulating power of the
dependent boilers is PID controlled based on the calculated setpoint and dependent boiler supply temperature.
Cascade CH setpoint adaption
When the system temperature is not high enough the setpoint for all boilers will be adjusted.
The boiler setpoint will be increased when the system temperature drops below Cascade_Setpoint and decreased
when it rises above Cascade_Setpoint temperature.
Depending Boiler
The CH mode for the cascade is defined by the setting of the managing boiler. CH mode settings on dependents
are ignored. In case a boiler is set as dependent (Address = 2-8/16) the setpoint is always provided by the
managing boiler.
The modulating power of the ALL boilers is PID controlled by the boiler itself by comparing the calculated setpoint
from the managing boiler and T_Supply. The managing boiler itself will be controlled in the cascade system as it
would as if it was a dependent boiler. Only the circulators and sensor inputs are used.
Boiler input Rates
A cascade system operates most effectively and efficiently when all of the boilers in the system are the same size.
SlantFin highly recommends that all the boilers in a cascade system are the same size/model. Sizing all the boilers
the same will prevent unbalanced wear on the boilers and their components.
C
– D
ASCADE
In the Boiler Settings menu, the installer must set the DHW_Mode of the managing boiler.
Available DHW modes in cascade are mode 1 or 2 for CH-boilers.
Dependent Boiler
In case a boiler is set as dependent (Address = 2-8/16) 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.
Boiler operation
Standalone burner
st
1
boiler (managing)
nd
2
boiler (depending)
rd
3
boiler (depending)
4
th
boiler (depending
↓
th
16
boiler (depending)
(CH) M
EATING ONLY
ANAGING BOILER
H
W
S
OMESTIC
OT
ATER
E93.1901EN032 Installation and Service Manual SlantFin VGH-CH / CO
2
PROM SETTING
Function of sensor input terminal 3-4
No function
System sensor
No function
No function
No function
No function
ETTINGS
121
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