2.1.3.4 Bearing vibration sensor
This chapter concerns the setting of seismic probes. For
setting of proximity probes refer to chapter 2.2.6.1
The vibration level of the machines is directly linked to the
duty and to the site characteristics.
We propose the following adjustment:
Vibration Alarm (*) = Site Highest Vibration level + 50%
Vibration Trip = Vibration Alarm + 50%
(*) do not pass over the values of the following chart
The machines are engineered to be able to withstand the
vibration level specified by the standard ISO8528-9 and
BS5000-3
Maximum levels for : reciprocating Internal combustion
engines
Nominal speed
(rpm)
kVA
Generator vibration level
(nominal conditions)
Overall
(mm/s rms)
(2–1000 Hz)
Any harmonics
1300 à 2199
> 250
< 20
< 0.5 mm ; pp
(5 – 8 Hz)
< 9 mm/s ; rm
(8 – 200 Hz)
721
à 1299
≥
250
< 20
>
1250
< 18
≤
720
>
1250
< 15
<
10 (*)
(*) generator on concrete base
Maximum levels for : Turbines
Turbines
(hydraulic ; gaz ; steam)
Max advised : 4.5
(overall ; mm/s rms)
2.2 ROTOR
2.2.1 Revolving field-coil
The Revolving field is a salient pole type, without any fixing
device as dove tail, cap bolt …
The revolving field is heat-shrunk onto the shaft
2.2.2 Excitation armature
The excitation armature is constructed by stacking
magnetic steel laminations. These steel laminations are
held in place by rivets.
The excitation armature is keyed and heat-shrunk onto the
shaft.
The windings are enamelled copper wires, class "F"
insulation (or "H", depending on the customer's request or
size of the machine).
2.2.3 Fan (machines: IC 0 A1)
The synchronous machine is characterized by a self-
ventilation system. A centrifugal fan is mounted between
the revolving field coil and the front bearing.
Air intake is at the rear of the machine and the exhaust on
the drive end side.
The fan consists of a hub, which is keyed and heat-shrunk
onto the shaft. The flange is made of welded steel,
attached to the hub with hexagonal head-cap screws. The
ventilation effect is obtained through, inclined blades. The
air is exhausted by centrifugation. The air inlet and outlet
must remain free during operation.
2.2.4 Rotating diode bridge
The rectifier bridge, comprising six diodes, is placed at the
rear of the machine. The rotating bridge is made of fiber
glass with a printed circuit to connect the diodes together.
This bridge is supplied with alternating current by the
excitation armature and supplies direct current to the
revolving field-coil. The diodes are protected against over
voltage by rotating resistors, or by varistors. These
resistors (or varistors) are mounted in parallel with the
revolving field-coil.
+
-
1
2
3
1 - Field
2 - Rotating resistors / varistors
3 - Exciter armature
The inner and outer rings are connected to the revolving
field-coil
1
2
1 - Outer ring
2 - Inner ring
The diode fastening screws must be tightened to the
correct torque.
Electric Power Generation
Installation and maintenance
5654
en - 2017.
10
/
a
LSA 5
2
.2
MHV
Industrial Range Alternators
- 4 pole
7
