H.w. Heating; Heating With Storage Tanks; General; Maximum Charging Time - Siemens RVD230 Basic Documentation

Siemens Building Technologies
HVAC Products
17 D.h.w. heating
17.1 D.h.w. heating with storage tanks

17.1.1 General

The RVD230 supports the following types of plants:
• Plants with coil type storage tanks, where the heating circuit and d.h.w. heating use a
common heat exchanger
• Plants with stratification storage tanks, where the heating circuit and d.h.w. heating use
2 separate heat exchangers
Space heating and d.h.w. heating use a pump or mixing heating circuit.
The heating energy required for storage tank charging is delivered either by an inter-
mediate circuit pump or a diverting valve with an upstream system pump.

17.1.2 Maximum charging time

The duration of d.h.w. charging can be limited to ensure the heating circuit will receive
sufficient heat also when d.h.w. heating cannot be terminated. The setting is to be
made on operating line 109 (setting ---).
On completion of the maximum duration of d.h.w. charging, d.h.w. heating will be lo-
cked for the same period of time.
With the parallel priority, the maximum duration of d.h.w. charging will be inactive.

17.1.3 Manual storage tank charging

Manual storage tank charging (also called d.h.w. push) is triggered by pressing the
operating mode button
ing when
• d.h.w. heating is not released
• the d.h.w. temperature lies inside the switching differential (also refer to subsection

17.1.4 "Forced charging")

• the d.h.w. operating mode is on standby (holidays, d.h.w. heating OFF)
Operating mode "D.h.w. heating ON" is switched on by activating manual d.h.w. charg-
ing; as an acknowledgement, the LED in the operating mode button flashes for 3 sec-
onds. Manual storage tank charging cannot be interrupted. It is terminated when the
required d.h.w. temperature is reached or the maximum d.h.w. charging time has
elapsed.
If, after manual storage tank charging, d.h.w. heating shall return to standby, operating
mode button must be pressed again.
Manual storage tank charging can be triggered via M-bus or LPB and passed on via
LPB (also refer to section 24.5 "Load management").
17.1.4 Forced charging
In the case of forced charging, the storage tank will be charged also when the d.h.w.
temperature does not drop below the d.h.w. switching differential.
This will take place depending on the program selected on operating line 101:
• Every day at the beginning of the first release period (release according to the d.h.w.
program or according to the heating program), or
• Every day at midnight if d.h.w. heating is continuously released (24-hour program)
Forced charging will be switched off when the d.h.w. setpoint is reached.
Basic Documentation RVD230
17 D.h.w. heating
for d.h.w. heating for 3 seconds. It also triggers d.h.w. heat-
67/130
CE1P2383en
27.05.2004