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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the EXP settings
18.10.2002
Wood-fired boilers
5.27 Protective startup of wood-fired boilers
•
The effect on the consumers can be adjusted
When using wood-fired boilers with no mixing valve for the maintained boiler return
temperature, you can select whether protective boiler startup shall have an effect on
the consumers.
Setting range
Unit
Factory setting
0 / 1
–
0
The settings have the following meaning:
0
Protective boiler startup is deactivated and does not affect the consumers.
1
Protective boiler startup affects the consumers.
The amount of heat drawn by the consumers will be restricted so that the boiler
temperature should not fall below the “Minimum boiler temperature for the release
of the pump” (operating line 370). This function is only active when the boiler pump
runs.
5.28 Minimum limitation of the return temperature
of the wood-fired boiler
•
The minimum boiler return temperature can be adjusted
The setting defines the permitted minimum boiler return temperature.
Setting range
Unit
Factory setting
8...140 °C
60
Partial diagram Ho 1
(for wood-fired boiler with a fixed bypass or a 4-port mixing
valve)
The amount of heat drawn by the consumers will be restricted such that the boiler re-
turn temperature will not fall below the temperature adjusted here.
The controller assesses the anticipated evolution of the temperature.
This function is active only when the boiler pump runs.
Partial diagram Ho 3
(with mixing valve for the maintained boiler return temperature)
The mixing valve uses the minimum limitation of the boiler temperature adjusted here
as a setpoint and adds appropriate amounts of boiler flow water to the boiler return.
If the wood-fired boiler strategy “Boiler temperature setpoint according to demand” is
selected, the mixing valve is also used for the flow temperature control. For that pur-
pose, the return temperature setpoint is raised until the required flow temperature is
reached.
Benefit
Description
Setting
Effect
Benefit
Description
Setting
Effect
