109/232
Building Technologies Boiler sequence controller RMK770 CE1P3132en
HVAC Products 7 Boiler control 23.04.2009
The boiler is released and the burner with its stages 1 and 2 or basic stage and modu-
lating part maintains the adjusted test mode setpoint.
The boiler is released and the modulating burner operates at the modulation level
according to the setting made. The burner is switched off when the maximum limit of
the boiler temperature is exceeded.
7.8 Control of the burner
If a boiler temperature sensor is configured, control is provided according to that sensor.
Main menu > Commissioning > Extra configuration > Boiler … > Inputs
Operating line Adjustable values / remarks
Boiler sensor Assign input
With the programmed types of plant, a boiler temperature sensor is assigned to each of
the 2 boilers. But that sensor can also be removed (---).
Boiler sequence management predefines a boiler temperature setpoint.
Without own boiler temperature sensor, the assumption is made that boiler temperature
limitation is ensured by an external boiler temperature limiter. In that case, control uses
the main flow sensor as the control sensor. For modulating burner control, a boiler
sensor is always required however.
7.8.1 2-position control of 1-stage burners
For 2-position control with a 1-stage burner, the following variables can be adjusted:
• Boiler switching differential
• Minimum burner running time
Main menu > Commissioning > Settings > … or
Main menu > Settings > Boiler … > Burner
Operating line Range Factory setting
Boiler switching differential 1…20 K 6 K
Burner run time min 0…60 min 4 min
The controller compares the actual value of the boiler temperature with the setpoint. If
the boiler temperature drops below the setpoint by half the switching differential, the
burner is started up. If the boiler temperature exceeds the setpoint by half the switching
differential, the burner is shut down.
TBoSp+
1
/
2
SDBo
0
1
3131D03
TBo
TBoSp
TBo
t
Y
B
TBoSp-
1
/
2
SDBo
SDBo Boiler switching differential
t Time
Tbo Boiler temperature
TboSp Boiler temperature setpoint
Y
B
Burner control signal
Stages 1 + 2 controlled
Modulating fixed
Boiler switching
differential
To Next Page
Loading...
