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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
4.37 Electric immersion heater buffer storage tank
K16 (ZuFu24)
•
Frost protection for the buffer and combi storage tank
•
Emergency
heating
•
Reheating in case of heat shortage
The electric immersion heater serves for frost protection, reheating or emergency
heating of the buffer or combi storage tank.
Setting range
Unit
Factory setting
--- / 101...110
K16
---
The auxiliary function will be activated as soon as electric immersion heater K16 is as-
signed a free terminal:
101...110 Electric
immersion
heater
K16
can be assigned to a free relay terminal
between Q101 and Q110.
---
No assignment made and the auxiliary function is not activated.
The effect can be subdivided as follows:
Frost protection function
The frost protection function becomes active as soon as the temperature acquired by
buffer storage tank sensor B4 drops below 7 °C. The electric immersion heater will be
switched on and remains on until the temperature at the sensor has reached 10 °C.
Reheating
If the heat sources are not able to satisfy the demand, the electric immersion heater
can be switched on. This occurs when heat shortage lasts a minimum of 5 minutes and
amounts to at least 50 K*min (integral).
In addition, the “Attenuated outside temperature” (operating line 704) must lie below the
set “Release threshold" (operating line 484).
Control of the electric immersion heater to the highest heating circuit setpoint takes
place via a fixed switching differential of 3 K. If the actual value at the control sensor
lies 3 K below the setpoint (display on operating line 702), the electric immersion heater
will be switched on. It will be switched off again when the actual value exceeds the set-
point.
The control sensor for reheating can be adjusted on operating line 485.
Function “Reheating” can be deactivated on operating line 484.
Emergency heating
When the heat sources are locked or are out of operation, the electric immersion heater
can be used to provide emergency heating.
For that, the “Attenuated outside temperature” (operating line 704) must lie below the
set “Release threshold” (operating line 484).
Control of the electric immersion heater to the highest heating circuit setpoint takes
place via a fixed switching differential of 3 K. If the actual value at the control sensor
lies 3 K below the setpoint (display on operating line 702), the electric immersion heater
will be switched on. It will be switched off again when the actual value exceeds the set-
point.
The control sensor for reheating can be adjusted on operating line 485.
Function “Reheating” can be deactivated on operating line 484.
Benefit
Description
Setting
Assignment
Effect