Operation - Riello ALU PRO power Series Instructions For The Installer And The Technical Assistance Centre

Functional notes
The control panel of the ALU PRO power boiler oversees:
- The domestic hot water priority function that gives
domestic hot water priority over heating hot water.
- The anti-freeze function:
The boiler's anti-freeze function. If the boiler's temper-
ature is less than H511 the burner comes on at maxi-
mum power until the boiler temperature reaches H512.
The anti-freeze system, active only with the outdoor
temperature sensor connected. If the outside temper-
ature drops below -5°C the pumps are switched on.
If the outdoor temperature is between -5° and 1.5°C,
the pumps are switched on for 10 minutes at intervals
of 6 hours; If outside temperature is above 1.5°C the
pumps are switched off.
HEAT REQUEST (WITH THREE SYSTEMS)
The ALU PRO POWER adjustment system has three
different types.
1 - with OT+ signal
2 - with external 0-10V control
3 - with room thermostat.
Once the heat request is finished, the system carries
out the post-circulation, namely the heating circulator is
started for the time set in parameter H543.
1 - Heat request with OT+ signal
The OT+ input is enabled only using the RVS communi-
cation kit available as an accessory ordered separately.
2 - Temperature request with 0-10V control
The 0-10Vdc input is translated into a temperature set-
point.
- 0Vdc - 1Vdc = no request;
- 1Vdc = request present with temperature setpoint at
the minimum permitted value;
- 10Vdc = request present with temperature setpoint at
the maximum permitted value.
The 0-10V regulators are: output 0-10V RVS63.
The management of the 0-10V device is set using the
selection of parameter C750, which can have the follow-
ing values:
- 0 = no 0-10V device is connected to the system;
- 1 = the 0-10V device is connected to the system; the
minimum stand-by signal is 0.5V. If the input read by
- The over-temperature dispersal function: if for any rea-
son the limit temperature C515 is reached, the boiler
switches off and the accumulated heat is dispersed
activating the system pump, if the last request was
heating, or the domestic hot water pump if the last
request was domestic hot water.
- The cascade control function: using the regulator
(accessory) it is possible to connect the boiler in cas-
cade up to a maximum of 16.
- The ignition/shut-off control function: to prevent repeat-
ed ignitions and shut-downs, the boiler stays off for a
minimum period of time. The boiler will only start up
again if the difference between the setpoint and the
actual boiler temperature exceeds a predetermined
value.
the main board is less than this threshold, the request
through TA is enabled; for higher values the TA input is
disabled;
- 2 = the 0-10V device is connected to the system;
the minimum stand-by signal is 0.5V. The TA input is
always disabled.
If both an opentherm device and a 0-10V device (param-
eter C750 in cases 1 or 2) are detected connected to the
system at the same time, any requests coming from the
latter will not be handled.
The display regarding the presence and the operating
status of the 0-10V input device is as follows:
- If C750 = 0: no signal is activated;
- if C750 = 1 or 2, and the input signal is greater than
0.5Vdc: the symbol in the top left of the 'LCD comes
on in a fixed manner;
- if C750 = 1 or 2, and the input signal is less than
0.5Vdc: the symbol in the top left of the 'LCD comes
on flashing;
3 - Enabling request with TA function
the heating request with a room thermostat is managed
only in the case where no device is connected to the
opentherm bus nor to the 0-10V input of the system
(C750 = 0 or else C750 = 1 with 0-10V input less than
the threshold of 0.5V). In the above-mentioned cases, the
closure of the thermostat generates a request with a set
point set from the interface keypad, if there is no outdoor
probe, or with a set point calculated on the basis of the
climatic curves, if there is an outdoor temperature sensor.

OPERATION

19
GENERAL