PRESSCON HORNIT N2, User Manual, Page: 5 / 71

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7.3.1 Fault and alarm messages for the PressControl (ECONOMY A and ECONOMY DUO) ............................... 55
7.3.2 Fault and alarm messages for the Touchscreen ............................................................................ 57
7.3.3 Fault and alarm messages for the PRESS-Basic control(ECONOMY B) ....................................................... 60
8 Maintenance and service ................................................................................................................................ 63
8.1 Expansion system maintenance ............................................................................................................................ 63
8.2 Compressor maintenance ............................................................................................................................... 63
9 Warranty ....................................................................................................................................................... 63
10 Appendix .................................................................................................................................................. 65
11 Document history
................................................................................................................................... 65
12 To conclude ................................................................................................................................................... 71
Introduction
The VERNIT HORNIT expansion system monitors and controls the pressure that is present in the expansion chamber of
a central heating system. It is applicable for the central heating systems in the horticulture industry. The system is
comprised out of a nitrogen generator with an air compressor, a set of pressure sensors that measure the water level
and pressure in a buffer tank and a control module that controls the nitrogen generator.
The central heating systems that are used in the horticulture industry store their heat in a vertical or horizontal buffer
tank. The buffer tanks are not fully filled with water but have an expansion chamber above the water. When looking at a
vertical buffer tank the expansion chamber is right above the water inside the tank. When looking at a horizontal buffer
tank the expansion chamber is also right above the water inside the tank but it can also be located in a separate
expansion vessel. The expansion chamber is intended for the water in the central heating system to expand and shrink
when the water is heated up or cooled down. During this process the pressure in the expansion chamber also changes.
The VERNIT HORNIT expansion system monitors the pressure in the expansion chamber. When the pressure becomes
too high then an overpressure valve relieves the extra pressure. When the pressure becomes to low then the VERNIT
HORNIT expansion system will produce nitrogen in order to get the expansion chamber pressurized again. The nitrogen
generator of the VERNIT HORNIT expansion system produces an air mixture with a nitrogen concentration of 99,0 vol. %
N
2
. The system uses nitrogen because it is an inert gas. Inert gasses have the ability to prevent the formation of rust
when it is available in a high concentration. The VERNIT HORNIT expansion system makes sure that there is always a
blanket of nitrogen present in the expansion chamber within the buffer tank and that it is kept at a steady overpressure.
Next to the pressure management of the nitrogen blanket, the VERNIT HORNIT expansion system also acts as a
monitoring device for the water level in the buffer tank. By using pressure sensors the system determines the height of
the water level. Once the water level becomes too high or too low, the VERNIT HORNIT expansion system will generate
the appropriate fault or alarm messages and can also send a stop signal to other relevant devices. The water level
monitoring is important for the conservation of the buffer tank. It prevents the water level from becoming too high and
damaging the roof of the buffer tank.