Technische Alternative UVR 16x2 User Manual

Solar start / drainback
135
Drainback parameters
Mode
Available for selection: Drainback func.
No. of functions included
Enter the number of functions included
Included functions
Sub-menu: List all the solar functions for the collector array
Activation time
Time window in which the drainback function is permitted
Filling time
When the system is started due to the radiation value or the
temperature differential between the collector sensor and cylinder
sensor, the outputs for system filling will be switched on for the
duration of the filling time.
Blocking time
Blocking time between two filling processes. This prevents the
Drainback function from starting too frequently. The blocking time
begins at the end of the filling process.
Radiation threshold (shown
only with radiation sensor)
Radiation threshold in W/m
2
at which a filling process is permitted.
➢ Without radiation sensor: For the Drainback function to start, the collector sensor of an
included solar function must be heated by insolation up to the solar function's start
threshold.
➢ The set filling time should be adjusted during commissioning so that it matches the actual
filling time of the system.
➢ When the collector is filled with the cold heat transfer medium, the collector temperature will
temporarily fall below the Diff. off switching differential between the collector sensor and
cylinder sensor. For this reason, it is possible to set a stabilisation time in the Solar
control function. This stabilisation time starts immediately when the solar function starts,
independently of the filling process, and starts again at the end of the filling process. The
solar circuit pump will keep running during that stabilisation time irrespective of the minimum
temperature at the collector and the temperature differential between the collector sensor
and cylinder sensor.
➢ In order to heat the collector more quickly during the stabilisation time, it is recommended to
control the speed of the solar circuit pump with PID control. That will cause the pump to run
at least at the minimum speed during the stabilisation time, allowing the start differential for
solar control to be exceeded.
Output variables for solar start / drainback
Flushing/filling process
Pump status ON/OFF; selection of the switching and analogue outputs
for the flushing or filling process
Time window
Status ON when the time window applies
Flush/fill timer
Display of a countdown of the flushing or filling time
Interv/block timer
Counter which counts down the interval or blocking time
Start attempts
Sum total of attempted starts today
Start att unsucc
Number of unsuccessful starts
Start attmpts since last run
Number of attempts since the solar thermal system last operated
correctly
➢ Drainback function: The selection of outputs for the filling process allows a booster pump
to be specified in addition to the solar circuit pump during the filling process.
➢ If the solar circuit pump has variable speed control in PWM or 0-10 V mode, it is advisable
to specify the analogue output for the filling process as well and to set its output value
(On) to 100 % or 10.00 V respectively. The pump will then be operated at full speed during
the filling process.

Technische Alternative UVR 16x2 Specifications

General

Brand	Technische Alternative
Model	UVR 16x2
Category	Controller
Language	English