Honeywell SDC Service Manual page 202

Hydraulic Components
Function
Control modes
202
For stratified discharge, an optional second buffer tank sensor
(PF2) can be connected to a variable input (VI1 to VI3).
The heat generator temperature is supplied by the temperature
measuring device of the heat generator.
Buffer or energy tanks are used for storing energy that is available
without control (e.g. from solar power system or wood boilers).
This energy buffer covers the energy demand from heating
circuits and hot-water systems.
Additional energy demand can be covered by controlled heat
generators (boilers).
The buffer loading pump function ensures that a controlled heat
generator supplies the additional energy to the buffer tank or the
heating and hot-water circuits, respectively.
If no controlled heat generator is used (e.g. heating by wood
boilers only), buffer functions such as forced dissipation into the
heating circuits can be used by connecting and activating buffer
sensor 1 to a variable input.
To support the full range of available combination options in
multivalent heating systems with buffer support, the control
system offers the possibility to set various control modes for buffer
operation. The different settings cause different processing
sequences of heat demand for heating circuit and hot water. In
the following, the different control modes are illustrated using
exemplary hydraulics layouts.
SDC / DHC
EN2H-0221GE51 R0812