DHW demand
70
DHW demand
Basic diagram:
Input
variables:
Output
variables:
Enable DHW demand
DHW temperature
= T.DHW
Effective set temperature = Time-related DHW
set value T.DHW EFF
Set temperature = Desired DHW temperature Set Temperature = Desired cylinder
temperature T.DHW SET
Status demand, indication of the output A
External Switch = Switching between “stand-
ard operation” according to the time program
(Status: OFF) and demand only of T.DHW
MIN (Status: ON)
Burner output = Assignment only makes sense
to analogue outputs A15 or A16
Simple description of the function:
Release of burner A if temperature in the cylinder (DHW temperature T.DHW) falls below the set
temperature set via the time window.
Special features:
The set temperature is also defined as an input variable in this function block. If it is only to be
used as a simple set value, you need only enter
User
as the "source." Now, it will appear as a
common function parameter in the function menu.
The set temperature indicates the “desired temperature“ within definable time windows. In or-
der to ensure a minimum cylinder temperature even outside the time windows, T.DHW MIN
(minimum DHW temperature) can be used to generate a demand outside these specified
times.
The effective set temperature T.DHW EFF currently set by the time window is available as an
output variable. If the cylinder exceeds this temperature, 5°C is output. The burner can then be
demanded via another module (such as heating demand) by comparing T.DHW EFF with the
buffer temperature.
The
set value
T.DHW SET as another output variable is the temperature that the user deter-
mines. Therefore, the setting of the desired cylinder temperature can be transferred to other
function modules.
The input variable "
EXTERNAL SWITCH
" can be used via a remote wage to switch between
standard operation in accordance with the time program and a demand based only on T.DHW
MIN (for instance vacation).
