FP USER INSTRUCTIONS ENGLISH 71576286 - 07/06
Page 9 of 35
1.9 Noise level
When pump noise level exceeds 85dBA 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 dB(A). 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
capacity, pipework design and acoustic
characteristics of the building. Typical sound
pressure levels measured in dB and A-weighted are
shown in the table below.
The figures are indicative only, they are subject to a
+3 dB tolerance, and cannot be guaranteed.
The values are based on the noisiest ungeared
electric motors which are likely to be encountered.
They are L
pA
sound pressure levels at 1m (3.3ft)
from the directly driven pump, for "free field over a
reflecting plane". For estimating L
wA
sound power
level (re 1 pW) add 14 dB(A) to the sound pressure
value.
If a pump only has been purchased, for fitting with
your own driver, then the "pump only" noise levels
from the table 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 this 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
pA
at 1 m reference 20
μ
Pa
(L
wA
sound power1 pW where L
pA
>85 dBA)
3550 r/min
2900 r/min
1750 r/min
1450 r/min
Motor size
and speed
kW (hp)
Pump and
motor
dBA
Pump
only
dBA
Pump and
motor
dBA
Pump
only
dBA
Pump and
motor
dBA
Pump
only
dBA
Pump and
motor
dBA
Pump
only
dBA
<0.55 (<0.75)
71
66
64
62
64
62
63
62
0.75 (1)
74
66
67
62
67
62
63
62
1.1 (1.5)
74
68
67
64
67
64
65
64
1.5 (2)
77
70
70
66
70
66
66
66
2.2 (3)
78
72
71
68
71
68
68
68
3 (4)
81
74
74
70
74
70
70
70
4 (5)
82
75
75
71
75
71
71
71
5.5 (7.5)
90 (
99
)
77
83
73
76
73
72
71
7.5 (10)
90 (
99
)
78
83
74
77
74
73
72
11 (15)
91 (
100
)
80
84
76
78
76
74
73
15 (20)
92 (
101
)
83
85 (
94
)
79
80
79
76
75
18.5 (25)
92 (
101
)
83
85 (
94
)
79
80
79
76
75
22 (30)
92 (
101
)
83
85 (
94
)
79
81
79
77
75
30 (40)
100 (
109
)
85 (
94
)
93 (
102
)
81
84
80
80
76
37 (50)
100 (
109
)
86 (
95
)
93 (
102
)
82
84
80
80
76
45 (60)
100 (
109
)
87 (
96
)
93 (
102
)
83
84
80
80
76
55 (75)
100 (
109
)
88 (
97
)
95 (
104
)
84
86 (
95
)
81
82
77
75 (100)
100 (
109
)
90 (
99
)
95 (
104
)
86 (
95
)
88 (
97
)
81
83
78
90 (120)
100 (
109
)
90 (
99
)
95 (
104
)
86 (
95
)
90 (
99
)
81
85 (
94
)
78
110 (150)
100 (
109
)
91 (
100
)
95 (
104
)
87 (
96
)
91 (
100
)
83
86 (
95
)
79
150 (200)
101 (
110
)
92 (
101
)
96 (
105
)
88 (
97
)
91 (
100
)
83
86 (
95
)
79
