Operating Tips; Installing The Temperature Sensor; Operating Pressure - Sonnenkraft ALU FIX PFMS2000 Manuel

Operating tips

Flushing and charging
For safety reasons, charging is to be carried out only when there is no direct sunlight or when the collectors are covered. Especially in areas liable to freezing, an anti-freeze/water mixture of
up to 40 Vol % must be used. To protect materials from excessive thermal load, the system should be charged and commissioned as soon as possible, after 4 weeks at the latest. If this is not
possible, the flange seals should be renewed before commissioning to prevent leaks.
Antifreeze that is not pre-mixed must be mixed with water prior to filling!
Recommended antifreeze for flat plate collectors: FSK
40 Vol.% proportion of antifreeze (Vol. 60%/water) - freezing point: -22° C/solidification point: -26° C
50 Vol.% proportion of antifreeze (Vol. 50%/water) - freezing point: -32° C/solidification point: -44° C
It may not be possible to completely empty collectors once they have been filled. For this reason, collectors exposed to frost should only be filled with a water/antifreeze mixture, also for
pressure and function tests. Alternatively, the pressure test can also be carried out using compressed air and leak detection spray.

Installing the temperature sensor

The temperature sensor must be mounted in the immersion sleeve of the flow connection of the hydraulic basic set. To ensure optimal contact between the sensor and the surrounding
environment, the gap between the sensor sleeve and the sensor element should be filled with a suitable conducting compound. All materials used for installing temperature sensors (sensor
element, conducting compound, cables, sealing and insulating materials) must be suitably temperature resistant (up to 250° C).

Operating pressure

The maximum operating pressure is 10 bar.
Bleeding
The system must be bled:
– when commissioning the system (after filling the collectors)
– 4 weeks after commissioning
– when necessary, e.g. if there are malfunctions
Risk of scalding due to steam and hot heat transfer fluid!
Only operate the bleeding valve if the temperature of the heat transfer fluid is < 60° C.
When bleeding the system, the collectors must not be hot! Cover the collectors and, if possible, bleed the system in the morning
Check heat transfer fluid
The heat transfer fluid must be checked every two years with regard to its antifreeze and pH value.
– Check antifreeze using antifreeze tester and replace or refill if necessary!
Target value is ca - 25° C and - 30° C depending on climatic conditions
– Check pH value with a pH indicator rod (target value approx. pH 7.5):
If the limit pH value is less than ≤ pH 7, replace the heat transfer fluid.
Maintenance of the collector
The collector or the collector array must be inspected visually, once a year, for any damage, leaks and contamination. Condensate can form in the collector after commissioning and during
times of the year with strong outdoor temperature fluctuations. This condensate disappears however after a few hours exposure to sunlight. Additional recommendations on operation and
maintenance can be found in SONNENKRAFT'S general documentation and instructions on commissioning and maintenance.
Decommissioning of the solar plant
If a solar plant is decommissioned for longer time it is recommended to cover the collectors to protect the solar equipment in the circuit (e.g fluid, pump, expansion vessel etc.) against long
time exposure to excess temperature.
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