Bitzer HS.8551 Mode D'emploi page 21

• Avoid quick pressure reduction with finely stepped
pressure control.
6 6 . . 7 7 . . 5 5 V V i i b b r r a a t t i i o o n n s s a a n n d d f f r r e e q q u u e e n n c c i i e e s s
Check the system carefully to detect any abnormal vi-
bration, check particularly pipes and capillary tubes. In
case of strong vibrations, take mechanical measures:
for example use pipe clamps or install vibration
dampers.
N N O O T T I I C C E E
!
!
Risk of burst pipes and leakages on the com-
pressor and system components!
Avoid strong vibrations!
6 6 . . 7 7 . . 6 6 C C h h e e c c k k i i n n g g t t h h e e o o p p e e r r a a t t i i n n g g d d a a t t a a
• Evaporation temperature
• Suction gas temperature
• Condensing temperature
• Discharge gas temperature
– min. 20 K above condensing temperature
– min. 30 K above condensing temperature for
R407C, R407F and R22
– max. 100°C on the outside of the discharge gas
line
• Oil temperature: see chapter Application ranges,
page 5
• Cycling rate
• Current values
• Voltage
• Prepare data protocol.
For application limits, see BITZER Software, Manual
SH-110 and brochures SP-110 and SP-120 respect-
ively.
6 6 . . 7 7 . . 7 7 C C o o n n t t r r o o l l l l o o g g i i c c r r e e q q u u i i r r e e m m e e n n t t s s
N N O O T T I I C C E E
!
!
Risk of motor failure!
The specified requirements must be ensured by
the control logic!
• Desirable minimum running time: 5 minutes!
• Minimum standstill time:
– 5 minutes
SB-110-3 SB-110-3 RUS
This is the time the control slider needs to reach
the optimal start position.
– 1 minute
Only if the compressor has been shut off from the
25%-CR step!
– Also observe minimum standstill times during
maintenance work!
• Maximum cycling rate:
– 6 to 8 starts per hour
• Switching time of the motor contactors:
– Part winding: 0.5 s
– Star-delta: 1 to 2 s.
6 6 . . 7 7 . . 8 8 P P a a r r t t i i c c u u l l a a r r n n o o t t e e s s o o n n s s a a f f e e c c o o m m p p r r e e s s s s o o r r a a n n d d
s s y y s s t t e e m m o o p p e e r r a a t t i i o o n n
Analysis show that compressor failures are most often
due to an inadmissible operating mode. This applies
especially to damage resulting from lack of lubrication:
• Function of the expansion valve – observe the manu-
facturer's notes!
– Position the temperature sensor correctly at the
suction gas line and fasten it.
– When using a liquid suction line heat exchanger:
Position the sensor as usual after the evaporator
– in no case after the heat exchanger.
– Ensure sufficiently high suction gas superheat,
while also taking into account the minimum dis-
charge gas temperatures.
– Stable operating mode under all operating and
load conditions (also part-load, summer/winter op-
eration).
– Bubble-free liquid at the expansion valve inlet,
during ECO operation already before entering the
liquid subcooler.
• Avoid refrigerant migration from the high-pressure
side to the low-pressure side or into the compressor
during long shut-off periods!
– Always maintain oil heater operation when the
system is at standstill. This is valid for all applica-
tions.
When installing the system in zones where the
temperatures are low, it may be necessary to in-
sulate the oil separator. At compressor start, the
oil temperature, measured under the oil sight
glass, should be 15 .. 20 K above the ambient
temperature.
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