Bitzer 2KTE-7K, Operating Instructions Manual

Page: 18 / 44

KB-130-6 18
2.3.1 General safety references
Danger!
Observe the high pressure levels of the refriger-
ant CO
2
①!
At standstill the pressure in the system will rise
and there is a risk of bursting!
Install pressure relief valves on the compressor
and on the aspiration and high-pressure sides in
system sections that can be cut off from both
sides.
Requirements and design according to
EN 378-2 and EN 13136.
①: Critical temperature 31.06°C corresponds to
73.84 bar, see chapter Pressure and saturated vapour
temperature table for CO
2
, page 27.
Danger!
Liquid CO
2
evaporates quickly, cools down at
the same time and forms dry ice!
Danger of cold burns and frost bites!
Avoid uncontrolled deflating of CO
2
!
When filling the system with CO
2
, wear gloves
and goggles!
Information
All transcritical BITZER CO
2
compressors are
equipped with a pressure relief valve to the at-
mosphere on the high-pressure side and option-
ally on the low-pressure side too.
However they do not replace the safety valves
of the system (EN 12693)!
Make sure that a free discharge to the atmo-
sphere of the pressure relief valves is possible.
Do not mount any pipes near the outlet of the
pressure relief valve!
CO
2
systems show typically low fluid temperatures. De-
pending on the type and the construction of the system,
the condenser and the liquid receiver, or only the liquid
receiver and if necessary the heat exchanger shall be
insulated to avoid air temperature at the surface to fall
below the dew point temperature.
• If necessary, take other measures to limit the high
pressure, such as:
– Using a pressure compensation vessel.
– For larger systems: mounting an additional cool-
ing unit to limit the pressure by back condensa-
tion.
Max. admissible pressure of the housing (as specified
on the name plate):
(from series No. 1680518739)
• Low-pressure side: 100 bar
• High-pressure side: 160 bar
Minimal opening pressure of the pressure relief valves
to the atmosphere
• Low-pressure side: 90 bar
• High-pressure side: 148 bar
Maximum admissible pressures during operation
• See Application limits in brochure KP-130 or KP-132.
3 Application ranges
Compressor
types 2MTE-4K .. 6CTE-50K
4PTC-7.F3K .. 4KTC-10.F4K
Permitted refri-
gerant R744
CO
2
of purity class N4.5 or com-
parable, or H
2
O < 5 ppm
Oil charge BSE85K
BSG68K ①
Application limits See brochure KP-130 or KP-132.
Tab. 1: Application ranges of transcritical CO
2
compressors
①: BSG68K: optional oil charge and standard oil
charge for applications with suction pressure > 40 bar
and/or high pressure > 120 bar (e.g. heat pumps).
The CO
2
purity class can have a higher H
2
O level if the
system is filled using a generously dimensioned filter
drier. It is recommended to change the filter drier sev-
eral times after commissioning.
Standard speed range for capacity control with fre-
quency inverter:
• 2MTE .. 4FTC and 6FTE .. 6CTE: authorised for 30
to 70 Hz operation.
• 4DTC .. 4CTC: authorised for 30 to 60 Hz operation.
• 4PTC-7.F3K .. 4KTC-10.F4K with integrated fre-
quency inverter: authorised for 30 to 87 Hz opera-
tion.
Particular applications
The use of the 2MTE-4K .. 6CTE-50K and
4PTC-7.F3K .. 4KTC-10.F4K compressors for systems
with hot gas defrosting or heat dissipation to a cold wa-