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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the EXP settings
18.10.2002
5.14 Switching differential of the bypass pump
(SDBP)
•
The switching differential of bypass pump Q12 can be adjusted
The switching differential is a criterion for activating and deactivating the bypass pump.
Setting range
Unit
Factory setting
0...20 K
6
The setpoint used for the switching differential is the minimum limitation of the boiler
return temperature. If the boiler return temperature (TRx) falls below the setpoint, the
bypass pump will be activated. If the boiler return temperature exceeds the setpoint by
half the switching differential, the bypass pump will be deactivated again.
The frequency of switching on / off changes as follows:
Increase of SDBP:
the bypass pump runs less frequently, but for longer periods
of time. Return temperature variations are greater.
Decrease of SDBP:
the bypass pump runs more frequently, but for shorter period
of time. Return temperature variations are smaller.
If the selected switching differential is too small, there is a risk of cycling.
The setting is active only when, on operating line 284
EXP
, setting 1 (according to the
boiler return temperature) has been selected.
23
92Z
5
0
TRx
ON
OFF
ON
OFF
°C
t
t
Q12
TRx Return
temperature
Q12 Bypass
pump
252
Setpoint of minimum limitation of the boiler return temperature
283
EXP
Switching differential of the bypass pump (SDBP)
Benefit
Description
Setting
Effect
Note
Important
