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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
Overtemperature protection d.h.w. storage tank
4.178 Functioning
To prevent excessive d.h.w. storage tank temperatures resulting from heat delivery by
the solar collectors, a number of protective functions are available. These functions are
triggered based on various temperature criteria and the priorities of the individual pro-
tective functions (operating lines 539 … 544).
The relevant temperature settings are the following:
•
D.h.w. storage tank safety temperature
(operating line 500
EXP
)
•
Difference between the maximum storage tank temperature (MSB) and the
d.h.w. storage tank safety temperature
(operating line 539)
•
Hysteresis
(operating line 540)
For assignment to the protective functions, the following priorities are available:
•
Priority 1
Will be activated when the actual storage tank temperature (TBx) exceeds the
maximum storage tank temperature (MSB), and deactivated when the actual stor-
age tank temperature falls by the adjusted hysteresis below the maximum storage
tank temperature (MSB).
•
Priority 2
Will be activated when the actual storage tank temperature (TBx) reaches a level
which lies half the temperature differential (operating line 539) below the storage
tank safety temperature, and deactivated when the actual storage tank temperature
falls below the maximum storage tank temperature (MSB).
To ensure overtemperature protection fully works, the d.h.w. sensor at the bottom must
be located at the level of the lower (or only) heat exchanger.
2392Z39a
MSB
TBx
Prio1
Prio2
ON
OFF
ON
OFF
=
=
500
EXP
d.h.w. storage tank safety temperature
523
Maximum d.h.w. storage tank charging temperature
539
Difference between the maximum storage tank temperature (MSB) and the d.h.w. storage tank
safety
temperature
540
Hysteresis d.h.w. storage tank cooling function with priority 1
MSB
Maximum d.h.w. storage tank temperature = operating line 500
EXP
– operating line 539
TBx
Actual value of the storage tank temperature acquired by the sensor at the bottom of the tank
Important
Functioning: