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DISCHARGING SYSTEM
In the event the system is stopped during winter, the water in the heat exchanger
can freeze damaging the heat exchanger irreversibly.
To prevent danger of freezing, three solutions are possible:
1.
Full water discharge from the unit;
2.
Using the resistances. In this case the resistances must always be supplied
with electrical power for the entire period of possible freezing (machine in
stand-by);
3.
Operation with glycol/water fluid, with a percentage of glycol based on the
minimum outdoor temperature expected.
WARNING! Make sure that air drain valves have been installed in all
the highest points of the hydraulic circuit and outside inhabited en-
vironments. To permit the circuit to drain, make sure that the drain
valves have been installed in the lowest points of the circuit and that
they are open.
ANTI-FREEZE PROTECTION
The addition of glycol is the only effective protection against freezing; the glycol/
water solution must be sufficiently concentrated to ensure proper protection and
prevent ice forming at minimum temperature provided for a given installation.
Take the necessary precautions if using non-passivated anti-freeze solu-
tions (monoethylene glycol or monopropylene glycol). Corrosion phenom-
ena may occur with these anti-freeze solutions in contact with oxygen.
However, always refer to the glycol supplier documentation to check its recom-
mended concentration.
IT IS FORBIDDEN! to insert glycol in the hydraulic circuit near the
pump intake:
— A high concentration of glycol and additives that exceeds the permissible limits
could cause the blockage of the pump;
— Do not use the pump as a mixer.
Summary of Contents for NRK 0150
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