andrews R18 Series, Technical Documentation Manual

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18IP22B
30
5.7 Formula to calculate
hot water requirements
Standard factory setting of the limit thermostat is 65 °C .
For higher temperature requirements contact your supplier.
They will make the necessary water quality measurements and
advise you with regards to high temperature settings and the
use of water softeners as required.
Water hardness in Maximum pH Maximum operating
ppm temperature in °C
0 - 80 8,4 90
80 - 250 7,6 85
250 - 350 7,2 80
350 - 500 7,0 60
Table 11 Maximum operating level
When the operating temperature exceeds the limit settings, the
water heater will be turned off and will not go to lock-out.
From table 12 select the application, the number of hot water
units and the formula to apply.
From table 13 as a function of the number of hot water units
determine delivery in l/h at 60 °C.
From table 14 apply the formula to obtain the performance of
the system.