Special Operating Modes - Dantherm Rcc 130 Bedienungsanleitung

Special operating modes

Preheating (with
preheating coil)
Defrosting
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In this section, the operation of the system under special conditions is described. For details
on the standard operating modes, please refer to page 9.
The preheating process is controlled through monitoring of temperatures registered by all
sensors inside the unit and its purpose is primarily to prevent the icing inside the heat
exchanger. Depending on the overall temperature conditions and in order to save energy, the
control will continuously attempt to exploit as little of available preheater capacity as
possible.
• When the preheater is active, the temperature of the outdoor air will be increased to
maintain a stable airflow and stable operation of the unit as a whole. Nevertheless, if some
harsh conditions appear in which the preheating coil can no longer ensure frost-proof
operation, the defrosting program will be activated.
• The effects experienced during the period of time in which the preheater is active will be
a higher exhaust air temperature and a slightly higher supply air temperature.
• If needed, further improvements and adjustments of the supply air temperature can be
achieved if an after-heater is applied.
The temperature setpoints during operation with an active preheating coil are fixed and
cannot be changed.
An optimal operation at low outdoor temperatures is ensured by the use of the preheating
coil. The defrosting process is the only remaining operating mode to protect the heat
exchanger against icing in the following cases:
• if the unit is not equipped with a preheating coil.
• if the unit is fitted with a preheating coil but the outdoor temperatures are so extreme
that the preheating capacity is not sufficient.
The defrosting process is a temporary state that is controlled in a similar way to the
preheating process. Defrosting is cancelled as soon as the system has reached the
temperatures required for normal operation.
INFO
The defrost mode is a safety mode. During defrosting the unit cannot change to another
operating mode until defrosting is completed. When the defrost mode is active, the HRC 3
dEF
indicates on the display.
There are two different procedures for defrosting:
• no fireplace in the house (default setting)
• fireplace in the house
You can change the defrosting procedure via the PC Tool. However, the setpoints for
defrosting cannot be changed.
INSTALLATION AND SERVICE MANUAL FOR PROFESSIONALS
Product description: Special operating modes