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Siemens Building Technologies
Basic Documentation RVL471
CE1P2524E
HVAC Products
17 Function block "Release of d.h.w. heating"
23.10.2002
With setting 1, d.h.w release depends on the setting made on operating line 121. In an
interconnected system of several controllers, that is, in the case of several heating
programs, the circulating pump runs if at least one of the connected controllers pro-
vides heating to the NORMAL temperature according to its heating program (independ-
ent of the operating mode), and is not in holiday mode.
Release of d.h.w. heating is shifted forward in time by one hour against the times of the
heating program. If optimum start control is active, the optimized switch-on times are
used - and not the times entered.
With plant types 4–x, 5–x, and 6–x, and the setting of “0” (own controller) on operating
line 121, d.h.w. heating will never be released since these plant types have no own
heating program.
The release of d.h.w. heating is explained using 2 examples, in which controllers A, B,
C and D are interconnected via the data bus:
Operating
line 121
Operating
line 123
Con-
trollers
Operat-
ing mode
Heating program, opti-
mization, holidays
Release
A
06:00...18:00, no optimi-
zation
B
07:00...23:00
C
07:00...22:00, optimum
start control shifts forward
by 2 hours
2
1
D
03:00...22:00, HOLIDAYS
D.h.w. heating is
released from
04:00 to 23:00
Operating
line 121
Operating
line 123
Con-
trollers
Operat-
ing mode
Heating program, opti-
mization, holidays
Release
A
06:00...18:00, no optimi-
zation
B
08:00...23:00
C
07:00...22:00, optimum
start control shifts forward
by 2 hours
2
1
D
05:00...21:00
D.h.w. heating is
released from
04:00 to 23:00
17.2.3
D.h.w heating during the holiday period
In holiday mode, d.h.w. heating is provided as follows:
Operating
line 121
Operating
line 123
D.h.w. heating
0
0, 1, or 2
No d.h.w. heating when own controller is in holiday mode
1
0, 1, or 2
No d.h.w. heating when all controllers in the same seg-
ment are in holiday mode
2
0, 1, or 2
No d.h.w. heating when all controllers in the intercon-
nected system are in holiday mode
Example 1
Example 2