HPXM USER INSTRUCTIONS ENGLISH 14983571 - 03/11
Page 9 of 48
1.9 Noise level
When pump noise level exceeds 85 dBA attention
must be given to prevailing Health and Safety
Legislation, to limit the exposure of plant operating
personnel to the noise. The usual approach is to
control exposure time to the noise or to enclose the
machine to reduce emitted sound. You may have
already specified a limiting noise level when the
equipment was ordered, however if no noise
requirements were defined then machines above a
certain power level will exceed 85 dBA. In such
situations consideration must be given to the fitting of
an acoustic enclosure to meet local regulations.
Pump noise level is dependent on a number of
factors - the type of motor fitted, the operating
conditions, pipework design and acoustic
characteristics of the building. The levels specified in
the table 1.1 are estimated and not guaranteed.
The dBA values are based on the noisiest ungeared
electric motors that are likely to be encountered.
They are Sound Pressure levels at 1 m (3.3 ft) from
the directly driven pump, for "free field over a
reflecting plane".
If a pump unit only has been purchased, for fitting
with your own driver, then the "pump only" noise
levels should be combined with the level for the driver
obtained from the supplier. If the motor is driven by
an inverter, it may show an increase in noise level at
some speeds. Consult a Noise Specialist for the
combined calculation.
For units driven by equipment other than
electric motors or units contained within enclosures,
see the accompanying information sheets and
manuals.
Typical sound pressure level, dBA, L
B
pA
B
at 1 m reference 20
μ
Pa (L
B
wA
B
sound power 1pW where L
B
pA
B
>85 dBA)
3500 rpm
2900 rpm
1750 rpm
1450 rpm
Motor size
and speed
kW (hp
)
Pump
only
dBA
Pump &
motor
dBA
Pump
only
dBA
Pump &
motor
dBA
Pump
only
dBA
Pump &
motor
dBA
Pump
only
dBA
Pump &
motor
dBA
<0.55
(<0.75)
72
72
64
65
62
64
62
64
0.75
(1)
72
72
64
66
62
64
62
64
1.1
(1.5)
74
74
66
67
64
64
62
63
1.5
(2)
74
74
66
71
64
64
62
63
2.2
(3)
75
76
68
72
65
66
63
64
3
(4)
75
76
70
73
65
66
63
64
4
(5)
75
76
71
73
65
66
63
64
5.5
(7.5)
76
77
72
75
66
67
64
65
7.5
(10)
76
77
72
75
66
67
64
65
11
(15)
80
81
76
78
70
71
68
69
15
(20)
80
81
76
78
70
71
68
69
18.5
(25)
81
81
77
78
71
71
69
71
22
(30)
81
81
77
79
71
71
69
71
30
(40)
83
83
79
81
73
73
71
73
37
(50)
83
83
79
81
73
73
71
73
45
(60)
86
86
82
84
76
76
74
76
55
(75)
86
86
82
84
76
76
74
76
75
(100)
87
87
83
85
77
77
75
77
90
(120)
87
88
83
85
77
78
75
78
110
(150)
89
90
85
87
79
80
77
80
132
(175)
89
90
85
87
79
80
77
80
150
(200)
89
90
85
87
79
80
77
80
160
(215)
(1)
(1)
(1)
(1)
83
84
81
83
200
(270)
(1)
(1)
(1)
(1)
85
87
83
85
300
(400)
87
90
85
86
315
(422)
87
90
85
86
355
(475)
87
90
86
87
500
(670)
88
(1)
86
(1)
1000
(1300)
90
(1)
88
(1)
1500
(2000)
90
(1)
90
(1)
(1) Noise levels of machines in this range should be based on actual equipment selected
For 1180 and 960 r/min reduce the 1450 r/min values by 2dBA
For 880 and 720 r/min reduce the 1450 r/min values by 3dBA
