Robur Direct Digital Controller, Installation, Use And Programming Manual

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Direct Digital Controller
58
Direct Digital Controller fw 4.013 – Ed. 01/2013
Figure 15
To make the regulation, the DDC manages switch-on and switch-off in cascade mode of the different types of
machines available, adapting the power supplied to the system heat load.
Machine categories
On the basis of their type, the machines are assigned to “categories” which have different properties to each
other, in a way to allow the control panel to manage the various types of machine with differentiated logic and
parameters. However, the machines have equivalent features within a category.
In heating mode, the existing categories are:
•
Category 1
The hot modules of all current Robur heat pumps are automatically assigned to this category.
•
Category 2
This category is reserved for future Robur products.
•
Category 3
All current Robur heat pumps in the AY line are automatically assigned to this category.
•
Categories 4 - 7
Any third party boilers can be assigned by the installer to these categories. For setting instructions refer to
paragraph 4.4.1.9 “Third party product category” on page 76.
Machine power of a category
The power of the individual machine belonging to it is defined via a parameter for each category.
For categories 1 and 3 (heat pumps and AY boilers) the pre-set value that cannot be modified is 35 kW.
For each of the categories 4-5-6-7 (third party boilers) the value that can be set by the installer is from 1 to
1680 kW.
Switch-on priority of a category
An ignition priority is associated to each category, expressed via a parameter with value from 0 to 6, which
determines the priority of use of the machines belonging to this category. The higher the value the higher the
priority.
For category 1 (Robur heat pumps) the value, which is set automatically and cannot be modified, is 6,
corresponding to maximum priority. For category 3 (Robur AY boilers) the value set by default is 4, but this
can be modified from 0 to 4. For categories 4-5-6-7 (third party boilers) the value set by default is 3, but again
this can be modified from 0 to 4. Therefore the system will always switch on the heat pumps first and will use
the boilers only when the thermal load is higher than the installed power of the heat pumps; the installer can
decide the relative switching on priority of all categories used for boilers, whether Robur or third party. Please
note that it is possible to assign the same switching on priority to several categories used for boilers; the DDC
will maintain a balanced operating time for boilers belonging to equal priority categories.
Number of stages of a category
The number of stages used by the regulation system is defined for every category. This is determined by a
parameter, which can be set in the range from 1 to 10.
The parameter must always be set at the value corresponding to the number of the stages desired.
If the number of machines is not an exact multiple of the parameter value, the system will use the number of
stages corresponding to the value of the parameter, but the stages will not be uniform, i.e. they will be made
up from different amounts of machines. The DDC will maintain a balanced operating time of the machines,
modifying the assignment of the machines to various stages of the category every 24 hours.
SP
SP Water set point
DF Water differential
DF