Charging With Refrigerant; Tests Prior To Compressor Start; Compressor Start; Checking The Rotation Direction - Biber OSKA9563 Instructions De Service

6.5 Charging with refrigerant

DANGER
Risk of bursting of components and pipelines
due to hydraulic excess pressure while feeding
liquid.
Serious injuries are possible.
Avoid overcharging the system with refrigerant
under all circumstances!
NOTICE
!
!
Risk of wet operation during liquid feeding!
Measure out extremely precise quantities!
Maintain the discharge gas temperature well
above the condensing temperature:
with NH at least 30 K.
3
NOTICE
!
!
Lack of refrigerant causes low suction pressure
and superheat condition!
Observe the application limits.
• Before charging with refrigerant:
– Use approved refrigerants only (see chapter Ap-
plication ranges, page 5).
– Switch on the oil heater.
– Check the oil level in the oil separator.
– Do not switch on the compressor!
• Charge condenser or receiver, on systems with
flooded evaporator, also the evaporator or liquid sep-
arator directly with liquid refrigerant.
• After commissioning, it may be necessary to add re-
frigerant: While the compressor is running, charge
with refrigerant on the suction side, preferably at the
evaporator inlet or in the liquid separator.

6.6 Tests prior to compressor start

• Oil level in the oil separator (in the sight glass area).
• Oil temperature in the oil separator (approx. 15 ..
20 K above ambient temperature).
• Setting and functions of safety and protection
devices.
• Setpoints of the time relays.
• Cut-out pressure values of the high-pressure and
low-pressure limiters.
• Cut-out pressure values of the pressure switches.
Record the setting.
• Are shut-off valves in the oil injection line open?
SB-520-1
NOTICE
!
!
Do not start the compressor if it was flooded
with oil due to faulty operation! It is absolutely
necessary to empty it!
Internal components may be damaged.
Close shut-off valves, depressurize the com-
pressor and drain oil via drain plug on the com-
pressor.

6.7 Compressor start

6.7.1

Checking the rotation direction

NOTICE
!
!
Risk of compressor failure!
Operate the compressor only in the intended ro-
tation direction!
Check the rotation direction during the first compressor

start:

• Connect the pressure gauge to the suction shut-off
valve. Close the valve spindle and open again by
one turn.
• Let the compressor start for a short time (approx.
0.5 .. 1 s).
• Correct rotation direction: Suction pressure drops im-
mediately.
• Incorrect rotation direction: Suction pressure in-
creases.
Reverse the polarity of the terminals on the common
feed line.
6.7.2 Start
Restart, slowly open the suction shut-off valve and ob-
serve the sight glass in the oil injection line. If there is
no oil flow within 5 s, switch off immediately. Check oil
supply!
6.7.3

Checking the oil level

Immediately after commissioning, carry out the follow-
ing checks:
• During operation, the maximum and recommended
oil level is within the sight glass area of the oil separ-
ator (the minimum oil level is secured by the oil level
switch).
• During the start phase, oil foam may appear which,
however, should decrease after 2 to 3 min. Other-
wise high proportions of liquid in the suction gas are
suspected.
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