Par 148 = 2 - Riello Condexa PRO NA 75P Installation, Operation And Service Manual

SETTING PARAMETERS OF THE CASCADE SYSTEMS

6.4.3 Par 148 = 2

In this mode the system manages the cascade so that the maxi-
mum number of boilers is on.
This mode is similar to mode 0 apart from the start-up and shut-
down rules.
In this case the rules based on the information illustrated by the
previous graph are still valid, with the following differences (in any
case, always applicable to the "balancing" option only):
To add an additional depending boiler, the managing boiler eval-
uates whether the sum of the power (calculated on the basis of
the fan speed) of all the active boilers is greater than the product
between the number of the active depending boilers increased
by one and the minimum power value (Par 152) increased by a
hysteresis value (defined by Par 153). [Σ( P1,P2,...Pn) > (n+1) * (Par
152) + (Par 153)].
To shutdown a boiler access, the managing boiler evaluates
whether the sum of the power (calculated on the basis of the fan
speed) of all the active boilers is less than the product between
the number of the active depending boilers and the minimum
power value (Par 152). [Σ( P1,P2,...Pn) < (n) * (Par 152)].
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NOTE: We must consider that the percentage of power varies
from a minimum of 1% and a maximum of 100% and there-
fore, the parameter values 152 and 153 are not to be taken as
the percentage of absolute power.
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