Manual for Induction Motors and Generators
Maintenance -
65
3BFP 000 050 R0101 REV E
Table 7-2. General tightening torques
NOTE: The values in
Table 7-2 General tightening torques
are general, and do not apply to
various items, such as diodes, support insulators, bearings, cable terminals or pole
fastenings, bus bar terminals, surge arrestors, capacitors, current transformers, rectifier
and thyristor bridges, or if some other value is given elsewhere in this manual.
7.4.2 Vibration and noise
High or increasing vibration levels indicate changes in the machine's condition. Normal levels
vary greatly depending on the application, type and foundation of the machine. The vibration
measurements and levels are discussed in detail in
. Some typical
reasons that might cause high noise or vibration levels are:
•
Alignment, see
Chapter 3 Installation and Alignment
•
Bearing wear or damage
•
Vibration from connected machinery, see
Tightening torque in Nm (pound-feet)
Property class 8.8 for bolts
Size
Oiled [Nm]
Oiled [pound
feet]
Dry [Nm]
Dry [pound
feet]
M 4
2.7
2.0
3.0
2.2
M 5
5.0
3.7
5.5
4.1
M 6
9
6.6
9.5
7.0
M 8
22
12
24
18
M 10
44
32
46
34
M 12
75
55
80
59
M 14
120
88
130
96
M 16
180
130
200
150
M 20
360
270
390
290
M 24
610
450
660
490
M 27
900
660
980
720
M 30
1200
890
1300
960
M 36
2100
1500
2300
1700
M 39
2800
2100
3000
2200
M 42
3400
2500
3600
2700
M 48
5200
3800
5600
4100