Beretta POWER PLUS Installation Instruction page 51

MODE: MAXIMUM NUMBER OF BURNERS ON (PAR.33=1)
All the burners are controlled by the same PID control algorithm, where the value controlled is the temperature in the
manifold, and the set point refers to the active circuit (set point in the high or low temperature circuit, or DHW set
point).
If the Manifold Temperature < set point – 5°C, the next burner is started.
The Master controller waits 30 seconds, and then
if the Manifold Temperature < set point - 5°C, another burner is started.
If the Manifold Temperature > set point + 2°C the last burner is stopped. The Master controller waits 30 seconds
before checking the situation again.
ADDITIONAL CASCADING MANAGEMENT FUNCTIONS
Rotation of burner ignition sequence
When Master controller is switched on, the burner with address 1 is the first in the sequence. After 24 hours, the
burner with address 2 becomes the first burner, while the burner with address 1 becomes the last in the sequence.
Limitation of starts/stops
In both cascading strategies, after each start or stop, a minimum time must expire before the Master can start or
stop any of the burners.
Rapid start/stop
In both modes a function is available for rapidly reaching stable operating conditions and shutting down.
If the Manifold Temperature < set point - 70°C the burners are started at 2 second intervals.
If the Manifold Temperature > set point + 4°C the burners are stopped at 2 second intervals.
Low load
The low load function prevents the burners from stating and stopping when there is a low heating demand. The
conditions for the activation of the Low Load function are checked on every Slave board, which sends the request
to enable the function to the Master.
During normal operation, the set point in the active circuit (set point in the high or low temperature circuit, or DHW
set point) is sent to the Slave boards, and the temperature of the heating unit is checked by each Slave board:
if the Boiler temperature > Set point – 8°C or
the Boiler temperature > 85°C - 8°C, the signal to start the burner is disabled.
When the Slave board reads a boiler temperature greater than 85°C three times when the burner is on, the heating
unit is stopped and the start-up procedure is enabled again.
Emergency function
In the event of faults on the Master board, there are two was of manually controlling the Slave boards:
- By eBUS and manifold probe
Disconnect the power supply from the system, unplug the BUS. Set the address 000000 on all the Slave boards (J10
and J17 OFF). Connect a power supply between 21 and 28 Vac to the BUS.
If the Manifold Temperature < Emergency Temp. (Par.40; pre-set to 70°C; settable between 10 and 80°C) all the bur-
ners operate at maximum output.
If the Manifold Temperature > Emergency Temp. + 5°C all the burners are stopped;
- By PC
Disconnect the power supply from the system, unplug the BUS and connect the PC interface. The output of the bur-
ners can be sent directly to the Slave boards using the PC.
b
In the event of faults, contact BERETTA or a suitably qualified person.
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