Danfoss PSH051, Инструкции по применению

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Application guidelines
19
FRCC.PC.021.A5.22
Operating conditions
R410A
POE oil
Motor supply
Compressor ambient
temperature
High ambient temperature
Low ambient temperature
PSH compressors are to be used with R410A refrigerant, with polyolester oil.
• R410A’s superior thermodynamical properties
compared to R22 and R407C refrigerants allow for
today’s massive – and necessary – switch to high
efficiency systems.
• Zero Ozone Depletion Potential (ODP): R410A
doesn’t harm the ozone layer.
• Global warming potential (GWP): R410A shows
a relatively high warming potential. However,
the GWP index denotes direct warming effect,
which is relevant only in case of release to the
atmosphere.
A more accurate index is T.E.W.I., for Total
Equivalent Warming Impact, which takes into
account indirect contributions due to running
energy costs.
• Because of the higher system efficiency it
allows to achieve, R410A is in this regard the best
refrigerant.
• As a near-azeotropic mixture, refrigerant R410A
behaves like an homogeneous substance,
whereas other zeotropic mixtures such as
R407C and other blends suffer a temperature
glide during phase change that lessens thermal
efficiency and makes them difficult to transfer
from a container to another.
• Reduced refrigerant mass flow, permitted by a
higher heat capacity, induce a lower sound level
of the installation as well as more compact and
lighter systems.
Polyolester oil (POE) is miscible with HFC's
(while mineral oil is not), but has to be evaluated
regarding lubrication ability in compressors. POE
oil has better thermal stability than refrigerant
mineral oil. POE is more hygroscopic and also holds moisture
tighter than mineral oil. It also chemically reacts
with water leading to acid and alcohol formation.
PSH scroll compressors can be operated at
nominal voltages as indicated in the section
“Motor voltage”. Under-voltage and over-voltage operation is allowed within the indicated voltage
ranges. In case of risk of under-voltage operation,
special attention must be paid to current draw.
PSH compressors can be applied from -31°F to
123.8°F ambient temperature, when charged
with refrigerant. The compressors are designed as 100% suction gas cooled without need for
additional fan cooling. Ambient temperature has
very little effect on the compressor performance.
In case of enclosed fitting and high ambient
temperature it’s recommend to check the
temperature of power wires and conformity
to their insulation specification. In case of safe
tripping by the internal compressor overload protection the compressor must cool down
before the overload will reset. A high ambient
temperature can strongly delay this cool-down
process.
Although the compressor itself can withstand
low ambient temperature, the system may
require specific design features to ensure safe and reliable operation. See section “Specific
application recommendations”.
Refrigerant and lubricants