KB-120-8
22
3
Application ranges
2MME-07K .. 6PME-40K
• Low-temperature applications in cascade and
booster systems.
• Medium-temperature applications with higher con-
densing temperatures (only 2MME-1K .. 2DME-7K).
• Maximum allowable pressures on the low pressure/
high pressure side: 100 / 100 bar.
2NSL-05K .. 4NSL-30K
• Low-temperature applications in cascade and
booster systems.
• Maximum allowable pressures on the low pressure/
high pressure side: 30 / 53 bar.
Compressor types
2NSL-05K .. 4NSL-30K
2MME-07K .. 6PME-40K
Permitted refrigerant
CO
2
①
CO
2
of purity class N4.5 or comparable, or H
2
O < 5 ppm
Oil charge
BSE60K: standard oil charge
BSE85K, BSE68K: optional
Application limits
see brochure KP-120
see brochure KP-122
Tab. 1: Application ranges of subcritical CO
2
compressors
Information
BSE60K for cascade systems!
BSE85K for booster systems!
①: The CO
2
purity class can have a higher H
2
O level if
the system is filled through a generously dimensioned
filter drier. It is recommended changing the filter drier
several times after commissioning.
②: Standard speed range for capacity control with fre-
quency inverter:
• 2MME-07K .. 2DME-7K: authorised for 30 Hz to
75 Hz operation.
• 4FME-7K .. 4DME-10K: authorised for 25 Hz to
70 Hz operation.
• 4TME-20K .. 4PME-25K: authorised for 25 Hz to
70 Hz operation.
• 6TME-35K .. 6PME-40K: authorised for 25 Hz to
70 Hz operation.
• 2NSL-05K .. 2CSL-6K: authorised for 30 Hz to 75 Hz
operation.
• 4FSL-7K .. 4NSL-30K: authorised for 25 Hz to 70 Hz
operation.
In applications with high pressure ratios, the adjustable
speed range may be limited. Consultation with BITZER
is required.
Special applications
Flooded systems require special measures for oil re-
turn. Moreover, given the usually very low suction gas
superheat, a generously sized heat exchanger to in-
crease the suction gas temperature is required. This
also applies to medium-temperature applications in
cold water systems using the compressors 2MME-1K ..
2DME-7K.
When designing such systems, consultation with
BITZER is recommended. For applications in hot gas
defrosting systems, consultation with BITZER is also
recommended.
Filter drier
The solubility of water in gaseous CO
2
is much lower
than in other refrigerants. This means that, especially in
low temperature applications, even a relatively small
amount of moisture from the refrigerant can freeze out
and block or clog the control valves. Therefore a gener-
ously sized filter drier and a sight glass with moisture
indicator for CO
2
are necessary.
