Sustained Mode; Switching Boilers On And Off - Siemens Synco 700 Series Basic Documentation

Summer operation
Switching boilers on
Switching on via the
temperature-time integral
Building Technologies
HVAC Products
On the basis of the plant's layout, the number of boilers required for heat generation in
the summer are usually known (e.g. for DHW heating). If the "Summer operation" state
is active in the boiler sequence manager, the number of boilers released can be limited.
Main menu > Commissioning > Settings > ... or
Main menu > Settings > Boiler sequence manager > Summer operation
Operating line
Number of boilers released
6.3.5

Sustained mode

When there is no demand for heat, there is no need for the boiler sequence to provide
heat. In that case, depending on the types of boiler used in the boiler sequence, all
boilers can be switched off or are maintained at a minimum temperature level. With
certain types of plant, it is important however to have heat available as quickly as
possible. For that purpose, a sustained mode can be defined. If there is no heat re-
quest, the temperature of the lead boiler is maintained at the adjusted sustained mode
setpoint. In that case, only the first stage of the lead boiler is released.
The minimum temperature of the relevant boiler is maintained depending on the pa-
rameter setting made, independent of the sustained mode setpoint.
Also, it can be selected whether or not a main pump – if installed – shall run during
sustained mode. If released in sustained mode, the main pump practically always runs.
Main menu > Commissioning > Settings > ... or
Main menu > Settings > Boiler sequence manager > Sustained mode
Operating line
Release main pump
Sustained mode setpoint
The binary control input for the boiler sequence release can interrupt sustained mode.
6.3.6

Switching boilers on and off

Based on the demand for heat and the current main flow temperature, the boiler se-
quence manager releases 1 or several boilers.
Main menu > Commissioning > Settings > ... or
Main menu > Settings > Boiler sequence manager > Control parameters
Operating line
Upward sequence integral
Downward sequence integral
Upward sequence delay
Shortened upward seq DHW
Additional boilers are released only if, for a certain period of time, the main flow tem-
perature stays below the neutral zone about the setpoint. The criterion used for switch-
ing on the second burner stage is a temperature-time integral.
TiDly
TFlw
TFlx
Boiler sequence controller RMK770
6 Boiler sequence management
Range
0...6
Range
Yes / No
---- / 8...140 °C
Range
0...500 K×min
0...500 K×min
0...255 min
0...100%
t
Factory setting
6
Factory setting
No
---- °C
Factory setting
200 K×min
50 K×min
5 min
0%
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CE1P3132en
23.04.2009