Tech Controllers ST-979, Руководство пользователя

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ST-979 user’s manual
11
V.i.3) Parallel pumps
In this mode, all active pumps and valves operate simultaneously. The valves maintain the pre-
set temperature and the water tank is heated to the pre-set temperature.
V.i.4) Summer mode
In this mode, the CH valves are closed to prevent unnecessary house heating. In the case when
the CH boiler temperature is too high, the valve will be opened as an emergency procedure ( it
requires activation of return protection!)
In this mode the water tank pump and the floor valves operate normally according to their
settings.
V.i.5) Floor heating
This function is used to deactivate control of the underfloor heating system.
Once this option is deselected, the controller closes all the valves which have been assigned the
underfloor type (see: valve parameters in Fitter’s menu). In default settings the function is active.
V.i.6) Buffer parameters
These parameters are used to adjust the controller operation in the case of heating system with
a buffer.
 Buffer
Once buffer function is activated (by selecting ON) in the controller menu, CH pump serves as
pump of the buffer in which two sensors are installed: upper (C1) and lower (C2). The pump
remains active until the pre-set temperature of buffer bottom is reached. When the temperature
drops below the pre-set buffer top temperature, the pump is activated again.
 Pre-set temperature top
This function enables the user to define the pre-set temperature for the upper part of the buffer
(sensor should be placed in the upper part of the tank). After this value is reached, the pump is
disabled (provided that the pre-set buffer temperature bottom has also been reached).
 Pre-set temperature bottom
This function enables the user to define the pre-set temperature for the lower part of the buffer
(sensor should be placed in the lower part of the tank).
 DHW function
If buffer is used in the heating system, it is necessary to specify how the water tank is connected:
- from CH boiler – the heating system in which DHW tank is connected directly to the CH boiler
(a separate circuit).
- from buffer – the heating system in which DHW tank is built in or connected to the buffer.
V.j) Thermal disinfection
Thermal disinfection involves DHW and it may be activated only in Water tank priority mode
or Parallel pump mode.
It involves raising the temperature of water in the DHW circuit to the minimum of 60 °C (required
disinfection temperature).
Current regulations require adjusting the DHW installation to enable thermal disinfection carried
out in the temperature of at least 60°C (recommended temperature: 70°C). Piping, fittings and
technological design of the DHW system need to meet this requirement.
DHW disinfection aims to eradicate Legionella pneumophila – bacteria which lower the cell-
mediated immunity. The bacteria often multiplies in hot water reservoirs (optimum temperature:
35°C), which often happens in water tanks.
After this function is activated, the water boiler is heated until the pre-set temperature reached.
The temperature is maintained for the whole disinfection time (e.g. 10 minutes). Next, the
standard operation mode is restored.
Disinfection temperature needs to be reached within 60 minutes from its activation (default
setting) Otherwise, the function will be automatically deactivated.
Any changes concerning this function may be introduced only in service mode.