Function Block Actuator Heat Exchanger; Operating Lines; Mode Of Operation; Control Process - Siemens RVD110 Basic Documentation

Note
Siemens Building Technologies
HVAC Products
12 Function block Actuator heat ex-
changer
12.1

Operating lines

Line Function, parameter
81 Actuator running time, actuator Y1*
82 P-band of control, actuator Y1*
83 Integral action time of control, actuator Y1*
85 Max. limitation of flow temperature
86 Min. limitation of flow temperature
12.2

Mode of operation

This function block controls the motorized valve through which, with plant types no. 2,
3, 7 and 8, the heat exchanger is controlled. This is the heat exchanger which, via the
common flow, supplies heat to both the space heating circuit and the d.h.w. circuit. The
respective actuator is actuator Y1.
In addition, this function block ensures minimum and maximum limitation of the com-
mon flow temperature acquired with sensor B1.
12.3

Control process

If the actual flow temperature deviates from the setpoint, the 2-port valve in the primary
return offsets the deviation in a stepwise fashion. The controller drives the valve's elec-
tric or electrohydraulic actuator whose ideal running time is 2 to 3 minutes.
The actuator's running time, P-band and integral action time must be entered on oper-
ating lines 81 through 83, depending on the type of plant.
12.4

Maximum limitation of the flow temperature

The setting range for the maximum limit value lies between the minimum limit value and
140 °C. The maximum limit value is to be entered on operating line 85.
At the limit value, the heating curve runs horizontal, preventing the flow temperature
setpoint from exceeding the maximum value.
This function can be deactivated.
Maximum limitation is not a safety function. For that purpose, a control thermostat or
thermal reset limit thermostat is required.
12.5

Minimum limitation of the flow temperature

The setting range for the minimum limit value lies between 8 °C and the maximum limit
value. The minimum limit value is to be entered on operating line 86.
At the limit value, the heating curve runs horizontal, preventing the flow temperature
setpoint from falling below the minimum value.
This function can be deactivated.
Basic Documentation RVD110, RVD130

12 Function block Actuator heat exchanger

Unit Factory setting
s 120
K 35
s 120
°C --- Variable...140
°C ---
Range
10...873
1...100
10...873
8...variable
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CE1P2381E
27.05.2004