Cycling Rate; Checking The Operating Data; Particular Notes On Safe Compressor And System Operation; Operation - Bitzer 2KES-05 Instructions De Service

• 4VE-7.F3Y .. 4NE-20.F4Y
Skip frequencies that may nevertheless give rise to res-
onances in the programming of the frequency inverter.
NOTICE
!
!
Risk of burst pipes and leakages on the com-
pressor and system components!
Avoid strong vibrations!
6.6.4

Cycling rate

The compressor should not start more than 8 times per
hour. Be sure to adhere to the minimum running time:
Motor power
< 5.5 kW
5.5 .. 15 kW
> 15 kW
6.6.5

Checking the operating data

• Evaporating temperature
• Suction gas temperature
• Condensing temperature
• Discharge gas temperature
• Oil temperature
• Cycling rate
• Current
• Voltage
Prepare data protocol.
6.6.6 Particular notes on safe compressor and
system operation
Analyses show that the vast majority of compressor
failures occur due to inadmissible operating conditions.
This is especially true for failures deriving from lack of
lubrication:
• Expansion valve operation – pay attention to the
manufacturer's guidelines!
– 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
and not after the heat exchanger.
– Ensure sufficiently high suction gas superheat,
while also taking into account the minimum dis-
charge gas temperatures.
24
Minimum running time
2 min
3 min
5 min
– Stable operation at all operating and load condi-
tions (also part load, summer/winter operation).
– Solid liquid at the expansion valve inlet.
• Avoid refrigerant migration (from high pressure to
low pressure side or into compressor) during longer
shut-off periods!
– Always maintain oil heater operation when the
system is at standstill. This is valid for all applica-
tions.
– Pump down system (especially if evaporator can
get warmer than suction line or compressor).
– Automatic sequence change for systems with
multiple refrigerant circuits.
Information
In the case of refrigerants with low isentropic ex-
ponent (e.g. R134a), a heat exchanger between
the suction gas line and the liquid line may have
a positive effect on the system's operating mode
and coefficient of performance.
Arrange the temperature sensor of the expan-
sion valve as described above.

7 Operation

7.1 Regular checks

Check the system at regular intervals according to na-
tional regulations. Check the following points:
• Operating data, see chapter Compressor start, page
23.
• Oil supply, see chapter Compressor start, page 23.
• Safety and protection devices and all components
for compressor monitoring (check valves, discharge
gas temperature sensors, differential oil pressure
limiters, pressure limiters, etc.).
• Tight seat of electrical cable connections and
screwed joints.
• Screw tightening torques (see KW-100).
• Refrigerant charge.
• Tightness.
• Prepare data protocol.

7.2 Condensation water

For applications with ambient air, low suction gas su-
perheat and/or insufficient sealing of the terminal box,
condensation water may form in the terminal box. In
KB-104-7