Setpoint Boost; Charging Boost; Flow Temperature Boost; Maximum Setpoint Of The D.h.w. Temperature - Siemens RVD230 Basic Documentation

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19.4

Setpoint boost

Setpoint boost ensures that the flow temperature required by the consumer to perform
its function (control) will be delivered by the heat source.

19.4.1 Charging boost

The charging boost for the d.h.w. setpoint can be set on operating line 116. This is the
difference between the heat demand to the heating medium (setpoint) and the setpoint
of the d.h.w. in the storage tank.

19.4.2 Flow temperature boost

The boost for the mixing valve or the heat exchanger in the d.h.w. circuit can be set on
operating line 118. In the case of direct d.h.w. heating via heat exchanger (plant types
x–4), the charging boost is also set on this operating line because the heat exchanger
is external.
19.5

Maximum setpoint of the d.h.w. temperature

On operating line 117, the maximum d.h.w. setpoint is defined. Depending on the type
of plant, the setting range is as follows:
Plant type
1–3, 1–9, 2–1, 2–2,
2–11, 3–1, 3–2, 5–9,
6–2, 7–2
0–x, 1–4, 1–8, 1–10,
2–6, 2–7, 2–12, 3–6,
3–7, 5–4, 5–10, 6–7,
8–4
In any case, the setting range is limited at a maximum of 95 °C.
19.6 D.h.w. heating with 2 storage tank sensors
With the plant types using a d.h.w. storage tank, the storage tank temperature can be
acquired with one or two sensors (B31 and B32).
When using two storage tank sensors, the amount by which the setpoint of the colder
storage tank sensor is lower than that of the warmer sensor can be set on operating
line 119.
When two sensors are used, the switch-off criterion for d.h.w. charging is reached when
• the sensor with the higher temperature has attained the d.h.w. setpoint, and
• the sensor with the lower temperature has attained the reduced d.h.w. setpoint.
The "reduced setpoint" for the sensor with the lower temperature allows the secondary
return temperature to be kept low until the end of d.h.w. charging, in spite of mixing in
the stratification tank.
The switching differential of the d.h.w. temperature still applies.
Basic Documentation RVD230
19 Function block Valve actuator d.h.w.
Minimum setting Maximum setting value
value
Reduced setpoint Minimum selection from:
(setting on operat-
• Setting value on operating line 117
ing line 42)
• Sum of setting values on operating
Reduced setpoint
(setting on operat-
Setting value on operating line 117
ing line 42)
lines 116 and 176 (maximum limit va-
lue of return temperature with d.h.w.
heating)
CE1P2383en
27.05.2004