Refrigerant Charge; Shaft Seal - Danfoss BOCK FK20 Operating Manual

5| Commissioning

5.5 Refrigerant charge

CAUTION!
Make sure that the suction and discharge line valves are open.
With the compressor switched off, add the liquid refrigerant directly to the condenser or receiver,
breaking the vacuum.
If the refrigerant needs topping up after starting the compressor, it can be topped up in vapour
form on the suction side, or, taking suitable precautions, also in liquid form at the inlet to the
evaporator.
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5.6 Shaft seal

F
ATTENTION! Failure to observe the following instructions can cause loss
I
TR
The compressor shaft is sealed to outside using a shaft seal. The sealing element rotates with
the shaft.
The following is especially important to ensuring fault-free operation:
The complete refrigerant circuit must be correctly executed and clean inside.
Heavy shocks and vibrations to the shaft as well as continuous cyclic operation are to be
avoided.
The sealing surfaces can stick together during prolonged downtimes (e.g. winter). Therefore, run
the system every 4 weeks for 10 minutes.
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Wear personal protective clothing such as goggles and protective
gloves!
Avoid overfilling the system with refrigerant!
ATTENTION!
To avoid shifts in concentration, zeotropic refrigerant blends
(e.g. R407C) must always be added to the refrigerating plant
in liquid form.
Do not pour liquid refrigerant through the suction line valve on
the compressor.
It is not permissible to mix additives with the oil and
refrigerant.
of refrigerant and damage to the shaft seal!
INFO! The shaft seal seals and lubricates with oil. An oil leakage
of 0.05 ml per operating hour is therefore normal. This applies
particularly during the run-in phase (200 – 300 h).
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