KB-120-8
21
2.3.1
General safety references
DANGER
Observe the high pressure levels of the refriger-
ant CO
2
(critical temperature 31.06°C corres-
ponds to 73.6 bar, see chapter Pressure and
saturated vapour temperature table for CO₂,
page 34)!
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 suction and high-pressure sides in
system sections that are lockable from both
sides.
Requirements and design according to
EN 378-2 and EN 13136.
DANGER
Dry ice may block the pressure relief valves!
Risk of bursting!
Do not mount any pipes near the outlet of the
pressure relief valve.
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!
CO
2
systems typically show low fluid temperatures. De-
pending on the system type and design, the following
measures are required:
• Condensers and liquid receivers or only the liquid re-
ceivers and possibly the heat exchanger must be in-
sulated to prevent the temperature from falling below
the dew point.
• If necessary, take other measures to limit the pres-
sure, such as:
– Use of a pressure equalisation vessel.
– For larger systems: installation of an additional
cooling unit to limit the pressure by back condens-
ation.
Maximum allowable pressures (standstill):
2MME-07K .. 6PME-40K
• Low pressure side: 100 bar
• High pressure side: 100 bar
2NSL-05K .. 4NSL-30K
• Low pressure side: 30 bar
• High pressure side: 53 bar
Due to the lower max. permissible pressure levels at
the low pressure side types 2NSL-05K .. 4NSL-30K are
equipped with a pressure relief valve (low pressure
side) to the atmosphere. According to EN 12693-2008
this pressure relief valve is not designed for protecting
the system. It only protects the compressor against in-
admissibly high pressures as soon as it (the com-
pressor) is shut off at both sides. The pressure relief
valves are attached to the suction shutoff valve. When
operating the compressor, open suction shutoff valve
completely (the pressure relief valve then becomes in-
active).
For compressors with line start permanent magnet mo-
tors (LSPM):
WARNING
Strong magnetic field!
Keep magnetic and magnetizable objects away
from compressor!
Persons with cardiac pacemakers, implanted
heart defibrillators or metallic implants: maintain
a clearance of at least 30 cm!
!
!
NOTICE
The PTC temperature sensor integrated in the
stator as a standard protects the LSPM motor
from overload when the temperature rises (e. g.
in case of prolonged locked rotor conditions). It
is recommended installing an additional over-
load protective device that reacts more quickly,
since repeated locking conditions would dam-
age the magnets.
