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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
Buffer storage tank overtemperature
4.160 Functioning
To prevent the buffer storage tank from exceeding a certain temperature level due to
heat supplied by the solar collectors or the wood-fired boiler, there are a number of
protective functions available. These functions are triggered based on various tem-
perature criteria and the priorities of the individual protective functions (refer to operat-
ing lines 489 through 495).
The relevant temperature settings are the following:
•
Buffer storage tank safety temperature
(operating line 450
EXP
)
•
Difference between the maximum storage tank temperature (MSP) and the
buffer storage tank safety temperature
(operating line 489)
•
Hysteresis
(operating line 490)
For assignment to the protective functions, the following priorities are available:
•
Priority 1
Will be activated when the actual value of the storage tank temperature (TPx) ex-
ceeds the maximum storage tank temperature (MSP), and deactivated when the
actual storage tank temperature falls by the selected hysteresis (operating line 490)
below the maximum storage tank temperature (MSP).
•
Priority 2
Will be activated when the actual value of the storage tank temperature (TPx) ap-
proaches a level that lies half the temperature differential (operating line 489) below
the safety temperature, and deactivated when the actual storage tank temperature
falls below the maximum storage tank temperature (MSP).
To ensure overtemperature protection is fully effective, the buffer storage tank sensor
at the bottom must be located at the level of the lower (or only) heat exchanger (that is,
it must be influenced by the heat exchanger).
2392Z38a
MSP
TPx
Prio1
Prio2
ON
OFF
ON
OFF
=
=
450
EXP
buffer storage tank safety temperature
472
Maximum buffer storage tank charging temperature
489
Difference between the maximum storage tank temperature (MSP) and the buffer storage tank
safety
temperature
490
Hysteresis of buffer storage cooling function with priority 1
MSP
Maximum buffer storage tank temperature = operating line 450
EXP
– operating line 489
TPx
Actual value at the coldest buffer storage tank sensor
Important
Functioning: