Julabo Presto Plus LH 47, Operating Manual

Page: 12 / 76

Operator responsibility – Safety instructions
12
2.3. Cooling water connection
Cooling water pressure (IN / OUT ) max. 6 bar
Difference pressure (IN - OUT ) 3.5 to 6 bar
Cooling water temperature <20 °C
Notice: Cooling water circuit
Risk of oil leaking from the refrigeration system (compressor) of the recirculating
cooler into the cooling water in case of a fault in the cooling water circuit!
Observe the laws and regulations of the water distribution company valid in the
location where the unit is operated.
Notice:
Danger of corrosion of heat exchanger due to unsuitable quality of cooling
water.
•
Due to its high content of lime, hard water is not suitable for cooling and causes
scale in the heat exchanger.
•
Ferrous water or water containing ferrous particles will cause formation of rust
even in heat exchangers made of stainless steel.
•
Chlorinated water will cause pitting corrosion in heat exchangers made of
stainless steel.
•
Due to their corrosive characteristics, distilled water and deionized water are
unsuitable and will cause corrosion of the bath.
•
Due to its corrosive characteristics, sea water is not suitable.
•
Due to its microbiological (bacterial) components, which settle in the heat
exchanger, untreated and unpurified river water and water from cooling towers is
unsuitable.
•
Avoid particulate matter in cooling water.
•
Avoid putrid water.
Recommended quality of cooling water:
pH
7.5 to 9.0
Sulfate [SO4 2- ]
< 100 ppm
Hydrocarbonate [HCO 3-]/sulfate [SO4 2-]
> 1 ppm
Hardness [Ca 2+, Mg 2+]/[HCO 3-]
> 0.5
°
dH
Alkalinity
60 ppm < [HCO 3-] < 300 ppm
Conductivity
< 500 μ S/cm
Chloride (Cl -)
< 50 ppm
Phosphate (PO4 3-)
< 2 ppm
Ammonia (NH3)
< 0.5 ppm
Free chlorine
< 0.5 ppm
Trivalent iron ions (Fe 3+)
< 0.5 ppm
Manganese ions (Mn 2+)
< 0.05 ppm
Carbon dioxide (CO2)
< 10 ppm
Hydrogen sulfide (H2S)
< 50 ppm
Content of oxygen
< 0.1 ppm
Algae growth
impermissible
Suspended solids impermissible