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Siemens Switzerland Ltd
User manual RVS61.843 CE1U2355en_02
HVAC Products 6 The settings in detail 23. November 2007
6.13 Cascade
Control
Line no. Operating line
3530 Release integral source seq
3531 Reset integral source seq
3533 Switch-on delay
3534 Forced time basic stage
When, with the heat source currently in operation, the demand for heat cannot be met -
the difference being the release integral set here - another heat source is switched on.
When the value is increased, additional heat sources are switched on at a slower rate.
When the value is decreased, additional heat sources are switched on at a faster rate.
When, with the heat source currently in operation, the demand for heat is exceeded by
the reset integral set here, the heat source with the highest priority is shut down.
When the value is increased, the heat sources operate for longer periods of time (in the
case of excess heat).
When the value is decreased, the heat sources are switched off at a faster rate.
Correct setting of the switch-on delay ensures that the plant maintains stable operating
states. This prevents frequent cycling of the heat sources.
With DHW requests, the delay time is fixed at one minute.
When switched on, every heat source operates with its basic stage for the period of
time set here. The next stage is released only when this period of time has elapsed.
Heat source sequence
Line no. Operating line
3540 Auto source seq ch’over
3541 Auto source seq exclusion
None
First
Last
First and last
3544 Leading source
Device 1…device 16
With automatic source sequence changeover, the heat source loads in a cascade can
be influenced by defining the order of lead and lag heat source.
Fixed order
Setting - - - defines a fixed order. In that case, the lead heat source can be selected on
operating line 3544; the other heat sources are then switched on and off in the same
order as the LPB device addresses.
Order according to the number of operating hours
On completion of the number of hours set, the heat source sequence in the cascade
changes. It is always the heat source with the next higher device address that takes on
the role of lead heat source.
Release integral source
seq
Reset integral heat
source seq
Switch-on delay
Forced time basic stage
uto source seq ch’over