Operating Tips; Installing The Temperature Sensor; Operating Pressure - Sonnenkraft SKR500 Manuel

Betriebsempfehlungen

Operating tips

Consigli per la messa in funzione
Recommandations d'emploi
Recomendaciones para el funcionamiento
Recomendações de funcionamento
Driftsanbefalinger
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 fl ange seals should be renewed before commis-
sioning to prevent leaks .
Antifreeze that is not pre-mixed must be mixed with water prior to fi lling!
Recommended antifreeze for fl at plate collectors: FS
40 Vol.% proportion of antifreeze (Vol. 60%/water) - freezing point: -22° C/solidifi cation point: -26° C
50 Vol.% proportion of antifreeze (Vol. 50%/water) - freezing point: -32° C/solidifi cation point: -44° C
It may not be possible to completely empty collectors once they have been fi lled. For this reason, collectors ex-
posed to frost should only be fi lled with a water/antifreeze mixture, also for pressure and function tests. Alter-
natively, the pressure test can also be carried out using compressed air and leak detection spray.

Installing the temperature sensor

The temperature sensor should be installed in the sensor sleeve nearest to the collector array fl ow. To ensu-
re optimal contact between the sensor and the surrounding environment, the gap between the sensor sleeve
and the sensor element should be fi lled 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 fi lling the collectors)
– 4 weeks after commissioning
– when necessary, e.g. if there are malfunctions
Risk of scalding due to steam and hot heat transfer fl uid!
Only operate the bleeding valve if the temperature of the heat transfer fl uid is < 60° C.
When bleeding the system, the collectors must not be hot! Cover the collectors and, if possible, bleed the sys-
tem in the morning .
Check heat transfer fl uid
The heat transfer fl uid must be checked every two years with regard to its antifreeze and pH value.
– Check antifreeze using antifreeze tester and replace or refi ll 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 fl uid.
Maintenance of the collector
The collector or the collector array must be inspected visually, once a year, for any damage, leaks and conta-
mination . Condensate can form in the collector after commissioning and during times of the year with strong
outdoor temperature fl uctuations. This condensate disappears however after a few hours exposure to sunlight.
Additional recommendations on operation and maintenance can be found in SONNENKRAFT'S general documen-
tation 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 fl uid, pump, expansion vessel etc.) against long time exposure to excess tempe-
rature .
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EN