Robur Direct Digital Controller User Manual

Direct Digital Controller
Direct Digital Controller fw 4.013 – Ed. 01/2013 63
Default values of the parameters and indications for correct choice of their values (categories 4 - 7)
Default values
Parameter Value of Categ. 4 - 7 Recommended setting
Machine power 35 kW
Set the power value in kW of the single
machine belonging to the category
Priority 3 Set a value between 0 and 4
Prevention time 2 minutes
Set a value suited to the type of
machine used
Minimum activation time 3 minutes
Set a value suited to the type of
machine used
Number of stages 10
Use the maximum value possible for the
number of machines present
Enable integral
6 °C * minutes
(10,8 °F * minutes)
Disable integral
8 °C * minutes
(14,4 °F * minutes)
Use the semi automatic configuration
(refer to paragraph 4.4.2.5.4 Regulation
parameters 89), which calculates the
value of these parameters according to
the other data set for all categories; the
calculation is made when exiting the
configuration panel
Table 2 - REGULATION PARAMETER DEFAULT VALUES HEATING SERVICE (categories 4 - 7)
Guide lines for the calibration of the parameters on the basis of the observation of the behaviour of the
system.
The values for the automatically set integrals using the semi-automatic configuration refer to plants with
normal heat inertia.
If systems must be regulated with very low or very high inertia values, it is possible that the regulation
parameters are calibrated differently.
Several guide lines are given below:
• The first indicator of a well-regulated system is that in normal conditions (with constant load) there is
only one intermittent stage.
If, however, there are several intermittent stages in normal running conditions, the integrals must be
increased, both prevention and enabling.
• If the response to load or set point variations is too slow:
o reduce the integrals, both prevention and enabling;
o reduce the number of stages, only after having acted with the previous option.
• If a single stage is too intermittent:
o maximise the number of stages;
o increase the differential [default = 2°C (3,6° F)] without exaggerating so as not to shift too far
away from the set point.
• If too marked overshoots are observed (the temperature rises too much over the set point):
o reduce the prevention inhibition;
• If too marked overshoots are observed (the temperature falls too much below the set point):
o reduce the enabling inhibition;
When a set point is requested that is very near to the operational limits of the machines, if the load is low the
system will regulate badly as the machines will tend to go continuously into limit thermostating.
To prevent this phenomenon that largely worsens yield, it is necessary to intervene with the activation of the
climatic curves or, alternately, reduction of the set point (in heating mode).
In the case of systems with common pump, where the phenomenon is particularly marked, it is also possible
to intervene by reducing the number of stages.
Third party boiler water pump delay
Only for categories 4, 5, 6 and 7, for third party boilers, this parameter is also present. For a given category,
the parameter is present when assigned to boilers with dedicated water pumps controlled by the Robur
system; this has the purpose of establishing the switch off delay for this type of water pump. If more than one

Robur Direct Digital Controller Specifications

General

Brand	Robur
Model	Direct Digital Controller
Category	Controller
Language	English