70/118
Siemens
Heating and D.h.w. Controller RVL481
CE1P2541en
Building Technologies
19 Function block "D.h.w. storage tank"
20.05.2008
19
Function block "D.h.w. storage tank"
Based on the settings made, this function block performs all d.h.w. functions required
for the plant types with a d.h.w. storage tank.
With plant types x–5 (electric immersion heater only ), this function block is not active
(except operating line 126) since the electric immersion heater provides the functions
independent of the RVL481.
The settings for solar d.h.w. heating are listed in the corresponding function block (op-
erating lines 201…208, refer to chapter "26 Function block "D.h.w. solar charging"").
19.1 Operating
lines
Line Function, parameter
Factory setting (range)
Unit
125
D.h.w. charging
0 (0…3)
126
D.h.w. temperature sensor / control thermostat
0 (0…5)
127
D.h.w. charging temperature boost
10 (0…50)
°C
128
Switching differential of the d.h.w. temperature
8 (1…20)
°C
129
Maximum d.h.w. charging time
60 (--- / 5…250)
min
130
Setpoint of the legionella function
--- (--- / 20…100)
°C
131
Forced charging
0 (0 / 1)
19.2 D.h.w. charging
The type of d.h.w. charging is to be entered on operating line 125. There are 2 basic
choices:
•
D.h.w. charging with hot water
•
D.h.w. charging alternately with hot water and the electric immersion heater
19.2.1 D.h.w. charging with hot water
The setting on operating line 125 is 0.
The d.h.w. storage tank is charged exclusively with hot water throughout the year.
19.2.2 Alternate
d.h.w.
charging
with hot water and electricity
The setting on operating line 125 is 1, 2, or 3.
In the winter, the d.h.w. storage tank is charged with hot water from the heating system
and, in the summer, with the electric immersion heater.
Changeover takes place based on the following criteria:
•
Changeover from hot water charging to the electric immersion heater takes place if
there has been no demand for space heating for at least 48 hours (changeover at mid-
night)
•
Changeover from the electric immersion heater to hot water charging is effected
when there is a demand for space heating. Depending on the setting made on oper-
ating line 125 (1, 2, or 3), different types of heat demand are considered for the
changeover criterion:
Operating
line 125
Criterion for changeover
1
Demand for space heating from own heating circuit
2
Demand for space heating from all controllers connected to
the data bus (LPB),
having the same segment number,
including those from the own heating circuit
3
Demand for space heating from all controllers connected to
the data bus (LPB), including those from the own heating
circuit
With plant types 4–x, 5–x, and 6–x, setting 1 on operating line 125 makes no sense,
since there is no own heating circuit. In that case, changeover to the electric immersion
heater would take place at midnight at the latest, after 48 hours of operation.
