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RECIPROCATING COMPRESSORS
18
SOUND AND VIBRATION MANAGEMENT
Compressor
model
Sound power level*
at 50 hz dB(A)
Sound power level*
at 60 Hz dB(A)
Acoustic
hood
code no.
without hood
with hood
without hood
with hood
NTZ048
72
65
72
65
7755001
NTZ068
71
64
75
68
NTZ096
84
78
84
77
7755002
NTZ108
82
75
82
75
NTZ136
77
71
84
77
NTZ215
84
78
88
81
7755002
NTZ271
84
78
88
81
(*) Operating conditions:
R404A, Evap. temp.: -35°C, Cond. temp.: 40°C, 400 V / 50Hz
Sound produced by a compressor is
transmitted in every direction by the
ambient air, the mounting feet, the
pipework and the refrigerant in the pi-
pework. The easiest way to reduce the
sound transmitted through ambient
air is to fit an acoustic hood accessory.
Because Maneurop® NTZ compressors
are 100% suction gas cooled and re-
Sound
Compressors in operation are one of
the sources of sound and vibration in
a refrigeration system. Both pheno-
mena are closely related.
quire no external cooling they can be
insulated or enclosed in a sound proo-
fing material lined compartment.
Sound transmitted by mounting feet,
pipework and refrigerant should be
treated the same way as vibration (see
next section).
Vibration
The mounting grommets delivered
with the compressor should always
be used. They will largely attenuate
the compressor vibration transmit-
ted to the base frame. These rubber
grommets have been selected and
calculated in accordance with the vi-
bration frequencies that are typical for
the compressor. For that reason other
grommet types or brands shall not be
used.
The base on which the compressor is
mounted should be sufficiently rigid
and of adequate mass to ensure the
full effectiveness of the mounting
grommets. The compressor should
never be rigidly mounted to the base
frame otherwise high vibration trans-
mission would occur and the service
life reduced. Suction and discharge
lines must have adequate flexibility in
3 planes. Eventually vibration absor-
bers may be required.
Vibration is also transmitted by the
refrigerant gas. Maneurop® NTZ com-
pressors have built-in mufflers to re-
duce pulsation. To further reduce vi-
bration an extra discharge line muffler
can be installed.
Содержание Maneurop NTZ048
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