Riello 20120391, Instructions For The Installer And For The Technical Support Service

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CONTROL PANEL
INSTALLATION
3.7.11 Night mode
Night mode allows the user to configure the unit to work with
specific parameters in a specific period of time. During the
night the unit capacity is limited. The number of running fans
is reduced (in cooling mode only), so that the noise level is
reduced.
The night time has a start time and a stop time, the same for
each day of the week. Night mode settings or the maximum
capacity value can be configured through the general Config-
uration menu.
3.7.12 Holidays
This function is used to set 16 holiday periods. Each period is
defined by three parameters:
− month
− start day
− holiday length.
During the holiday the controller is in occupied or unoccupied
mode, according to the periods indicated as holiday. Each hol-
iday period can be modified by the user in the Configuration
menu.
To change the holiday periods:
− Scroll the Configuration Menu.
− Select Holiday .
− Choose the holiday period, e.g. HOLDY_01.
− Set the Holiday Start Month [HOL-MON], Start day [HOL-
DAY], Length (days) [HOL-LEN].
Parameter Default Range
[HOL-MON] 0-12 0
[HOL-DAY] 0-31 0
[HOL-LEN] 0-99 0
3.7.13 Desuperheater option
NXC chillers and NXH heat pumps can be equipped with desu-
perheater allowing for better energy management.
The desuperheater is used to extract high pressure and high
temperature heat from the refrigerant to "desuperheat" it re-
ducing refrigerant pressure. The steam entering the desuper-
heater is not completely condensed, therefore the refrigerant
steam must be channelled in a separate heat exchanger where
the condensation process will take place.
To set the minimum condensing setpoint [min_sct]:
− Move to the Main Menu.
− Select Setpoint .
− Set Desuperheater Min Sct
Desuperheater Min Stc [min_stc]
Range
Default
From 26.7 to 60.0°C 40.0°C
From
80.0 to
140.0°F
104.0°F
3.7.14 Defrost cycle for heat pumps
When the outdoor air temperature is low and the ambient hu-
midity is high, there is a greater risk of frost forming on the coil
external surface. The frost covering the external coil can de-
crease the air flowing into the coil, thus reducing unit perfor-
mance. The control unit activates the defrost cycle whenever
necessary in order to eliminate the frost from the coil.
During the defrost cycle, the circuit is forced into cooling mode.
To prevent the water circuit from cooling, the optional electric
heating can be started. The defrost cycle lasts up to when the
defrost temperature is reached.
3.7.15 Master/Slave unit
The control system allows controlling the master/slave of two
units connected with the network (owner protocol). The mas-
ter unit can be controlled in local, remote mode or through
network commands, while the slave unit remains in Network
mode. All control commands of the master/slave unit (start/
stop, setpoint selection, demand limit, etc.) are managed
through the master unit. Commands are automatically trans-
mitted to the slave unit.
If the master chiller is turned off while the master/slave func-
tion is active, the slave chiller will stop. In some situations, the
slave unit can be started first to ensure that the runtime of the
two units are uniform.
In case of communication error between the two units, each
unit will go back to work independently up to when the error
is removed. If the master unit stops due to an alarm, the slave
unit is authorised to start.
9
The Master/Slave unit can be configured by R Technical
Support Service only.