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Siemens Building Technologies
Basic Documentation RVA63.242, RVA53.242
CE1P2373E
Landis & Staefa Division
Description of heating engineer settings
26.03.2001
4.77 Demand for heat with reduced d.h.w. setpoint
Selectable type of heat demand with reduced d.h.w. setpoint.
In connection with alternative sources of energy, an early release of heat generation
(boilers) for d.h.w. heating outside the main occupancy times is often undesirable. A
choice of 2 different procedures is available releasing the boiler earlier or later.
Setting
Setting range
Unit
Factory setting
0 / 1
–
1
The setting determines whether or not heat generation will be released for maintaining
the reduced d.h.w. setpoint:
0
Application with buffer storage tank and alternative heat source:
Outside the main occupancy hours, an attempt is made to bring the d.h.w.
temperature to the reduced setpoint level using energy from the buffer storage
tank. This means that the d.h.w. charging pump runs but the demand for heat
will be suppressed.
The boiler for d.h.w. heating will be released only (charging to the nominal d.h.w.
setpoint) when the d.h.w. temperature has dropped below the reduced setpoint
by twice the amount of the d.h.w. switching differential (51
OEM
).
1
Standard procedure:
Outside the main occupancy hours, the d.h.w. temperature is raised to the level
of the reduced setpoint. This is accomplished by sending a heat demand signal
to the heat source (single boiler or cascade).
Benefit
Description
Effect