Ferroli RMA series, Инструкция по установке и эксплуатации

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34
CONTROL SYSTEM
Operating mode selection
It's possible to select the operating mode by accessing the “Operating mode” menu :
- Cooling
COOL
- Heating
HEAT
- STAND BY *
StdBY
* The antifreeze function is still active.
Remote STAND BY
This function allows remote selection of the STANDBY mode. If the input is activated (open contact) the controller is in STANDBY
mode and the operating mode can not be modified from the user interface.
The digital input used is DI4. Set the parameter
CF19
=
-27
to enable this function.
Remote Cooling-Heating
This function allows remote selection of Cooling or Heating mode. If the input is activated (open contact) the unit is in heating mode. If
the input is not activated (closed contact) the unit is in cooling mode. The operating mode can not be modified from the user interface
(but STAND BY mode can be selected).
The digital input used is DI5. To enable this function set the parameter
CF20
=
14
.
Set point
The set point value in cooling (
COOL
) and heating (
HEAT
) can be set by accessing the “
Status
\
Sp
” menu. These values must be
between a fixed maximum and minimum value. The purpose of the controller is to keep the water temperature at the unit inlet as close
as possible to the set value, by activating the compressor according to an on-off logic.
Operating in heat pump mode
For all the heat pump units the parameter
tr01
enables operation in heat pump mode when its value is 1. It is possible to set an ou-
tdoor air temperature value (parameter
tr17
) below which heat pump mode is locked (in any case the integrative electrical heaters,
if present, remain activated).
Antifreeze
The plate heat exchanger is protected by the activation of an electrical antifreeze heater and the activation of the antifreeze alarm,
occurring in sequence when the temperature of the water at the exchanger outlet reaches dangerous values. The buffer tank is pro-
tected by the antifreeze heater (accessory) activated together with the plate heat exchanger heater.
When the outdoor air temperature approaches 0°C, if the unit is not working, the pump is activated in any case to prevent excessive
cooling of the water in the pipes.
Integrative electrical heaters
The parameter
Hi02
enables the electrical heaters, as integration of the heat pump, when its value is 1. The heaters are activated
according to a two step logic depending on the unit inlet water temperature. When present, the heaters also carry out the storage
tank antifreeze function .
Dynamic defrost
The activation limit is modified in a dynamic way according to the outdoor air temperature.
Serial communication
The device is configured to communicate on a serial line using the MODBUS protocol. When the device is connected, it must be
assigned an address univocally identifying it among all the devices connected to the same serial line (“Modbus individual address”).
This address must be between
1
and
247
and is configurable by means of the parameter
CF63
(see section on serial communication).
Operating hours recording
The controller can record the operating hours of compressor and pump. Access the “
Status
\
Hr
” menu to see the values. The hours
are reset by pressing the SET button for long, while the hours of operation are displayed.
Power failure
In case of a power failure, when the power is restored the controller will return to the status before the power failure. If a defost cycle
was in progress the procedure is cancelled. All safety timing in progress are cancelled and reinitialized.
Clock
The controller is equipped with an internal clock to record date and time of each alarm occurred during unit operation (see “Alarms
memory”). The clock can be set by accessing the “
Status
\
CL
” menu.
Modulating pump management
It is possible to set the rotational speed of the modulating pump in order to get the water flow rate required to mantain the desired
temperature difference between the water inlet and outlet. Modifying the parameters
PI05
(for cooling mode) and
PI11
(for heating
mode) from 40 to 100, the rotational speed of the pump changes from the minimum to the maximum speed.
Functions available for the user