Panasonic WH-ADF0309J3E5CM Service Manual page 229

22.1.4 Specifications
22.1.4.1 Specifications of fresh water was heat transfer medium in brazed heat
exchanger
Parameter Quality Limits for Tap Water on the Secondary Side
Temperature Below 60°C
pH 7 to 9
Alkalinity 60mg/l < HCO₃ < 300mg/l
Conductivity < 500μS/cm
Hardness [Ca⁺, Mg⁺] / [HCO₃⁻] > 0.5
Chloride < 200mg/l at 60°C
Sulphate [SO₄²⁻] < 100mg/l and [HCO₃⁻] / [SO₄²⁻] > 1
Nitrate NO₃ < 100mg/l
Chlorine < 0.5mg/l
22.1.4.2 External filter
Solids in the water must be filtered.
Minimum filter mesh size required for the field supply external filter in the water inlet is 20 mesh.
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