Ound And Vibration Management; Starting Sound Level; Running Sound Level; Stopping Sound Level - Danfoss Performer SH090 Selection & Application Manuallines

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PPLICATION GUIDELINES

Starting sound level

Running sound level

Stopping sound level

Sound generation in a
refrigeration or air
conditioning system
S

OUND AND VIBRATION MANAGEMENT

During start-up transients it is natural for the com-
pressor sound level to be slightly higher than dur-
ing normal running. SH scroll compressors exhibit
very little increased start-up transient sound. If a
compressor is miswired, the compressor will run
Compressor acoustic hoods have been developed
to meet specifi c extra-low noise requirements.
The covers and bottom insulations incorporate
50 Hz
Model
Sound power Attenuation
dB(A)
SH090 70
SH105 71.5
SH120 72.5
SH140 * 72.5
SH161 * 73.5
SH184 75
SH180 80
SH240 82
SH300 82
SH380 83
Sound power and attenuation are given at ARI conditions, measured in free space
* For SH140 code 3 and SH161 code 3 use acoustic hood reference 120Z0135
** Inferior hood is provided in surface sump heater accessories for SH180-240-300-380 models.
Materials are UL approved and RoHS compliant
SH compressors are equipped with a discharge
valve which closes at compressor shut down and
thus prevents the compressor from running back-
wards. This reduces the stopping sound to a me-
tallic click caused by the closing valve.
Typical sound and vibration in refrigeration and
air conditioning systems encountered by design
and service engineers may be broken down into
the following three source categories.
Sound radiation: this generally takes an airborne
path.
FRCC.PC.007.B5.02
in reverse. Reverse compressor rotation is charac-
terized by an objectionable sound. To correct re-
verse rotation, disconnect power and switch any
two of the three power leads at the unit contactor.
Never switch leads at the compressor terminals.
sound proofi ng materials and off er excellent high
and low frequency attenuation.
60 Hz
Sound power Attenuation
dBA dB(A)
6 72
6 74
6 75
6 76
6 77
6 78
6 85
6 86
6 86
6 87
When the pressure diff erence or gas fl ow at shut
down should be very low, this can delay the dis-
charge valve from closing and lead to a longer
noise duration.
Mechanical vibrations: these generally extend
along the parts of the unit and structure.
Gas pulsation: this tends to travel through the
cooling medium, i.e. the refrigerant.
The following sections focus on the causes and
methods of mitigation for each of the above
sources.
Acoustic hood Inferior hood
code number code n° **
dbA
6 120Z0034
6 120Z0035
6 120Z0035
Not available
6 120Z0035
6 120Z0035
6 120Z0135
4 120Z0022 120Z0353
4 120Z0022 120Z0353
4 120Z0022 120Z0353
4 120Z0022 120Z0353
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