Section 7: Maintenance; Section 8: Troubleshooting; Section 9: Design Data; Water Quality Notes - Pfannenberg PWS Serie Installations-, Betriebs- Und Service-Handbuch

SECTION 7: MAINTENANCE

Pfannenberg air/water heat exchangers are
maintenance-free.
Use of a water filter is essential if the cooling water
is contaminated. Please refer to the "Water Quality
Notes" section.
Check the condensation water drainage equipment
at regular intervals.

SECTION 8: TROUBLESHOOTING

Condensation water drainage out of the electrical
panel enclosure must be ensured when the device is
installed.
To prevent frost damage the temperature in the
water circuit must not fall below the minimum
permissible water temperature of +1°C anywhere in
the system.
If the device is stored or transported at temperatures
below freezing the water circuit must be completely
emptied using compressed air.
Common contamination forms and remedies
Water Contamination
Mechanical contamination
Excessive hardness
Moderate mechanical contaminant and hardness
promoting substance content
Moderate chemical contaminant content
Biological contamination - sludge bacteria, algae

SECTION 9: DESIGN DATA

Please refer to the cooling unit individual
technical data sheets for the following:
Dimensional Data
Mounting Cutout
Circuit Diagrams

9.1 Water Quality Notes

The following guidelines must be complied with to
ensure safe and reliable operation of air/water heat
exchangers.
Cooling water should not contain any sedimentation,
should be of low hardness (low carbon hardness
in particular), especially for re-cooling. However, it
should not be so soft that it corrodes material/s used
in the exchanger.
When recycling cooling water the saline content due
to evaporation of larger quantities of water must not
be too high (increasing concentrations of dissolved
substances increase electrical conductivity, resulting
in the water becoming more corrosive).
Constantly remove some enriched water and replace
it with an equal amount of fresh water.
Water containing gypsum is unsuitable for cooling,
as it tends to cause scale deposits, which are very
hard to remove.
Cooling water should be iron- and manganese-
free (deposits leading to piping blockage may
otherwise result). Organic substances (sludge and
microbiological contaminants)should only be
present in the water in very small amounts.
Remedy
Filter water using -Sieve filters
- Gravel filters
- Cartridge filters -Pre-coated filters
Soften water using ion exchange
Treat water using stabilisers or dispersants
Treat water using passivation media and / or inhibitors
Treat water with biocides
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