23
___________________________________RAH / PAH Ka_________________________________
After the seal test made with water, if the system will be started after a long break or the ambient temperature can go down to values near to
or lower than 0°C, the circuit must be drained and charged with an antifreeze liquid.
Make the compressors start only after the evaporator water circulation pumps will be on; this can be obtained, for example, by an electrical interlock (see
wiring diagram attached to the Handbook).
3.5.3 CHEMICAL-PHYSICAL PROPERTIES OF EVAPORATOR WATER
In the following table there are, just as an indication, the main values of chemical and physical properties of the water to be respected to avoid corrosion or any
sediment. To this purpose it is advisable a yearly check of the PH stability.
pH
SO
4
ppm
HCO
3
/ SO
4
ppm
°d
ppm <50
µS / Cm <500
PO
4
ppm <2
NH
3
ppm <0,5
ppm <0,5
Fe
3+
ppm <0,5
2+
ppm <0,05
Fe
3
O
4
ppm 0
CO
2
ppm
H
2
S <50
O
2
ppm
°C <45
pS = Logarithm of the suspended solids in ppm and measured at water temperature falling point
pAlc = Logarithm of the alkalinity factor in ppm CaCo3
pCa = Logarithm of the limestone hardness in ppm CaCo3
To Next Page
Loading...
