Installation; Assembly; Drive; Alignment/Leveling - WEG G truck Serie Manual De Instalación, Operación Y Mantenimiento

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5 INSTALLATION

5.1 ASSEMBLY

Assembly should be made on a maximum difference of
two degrees on surface level. There must be a minimum
separation of 50 mm on the DE to provide adequate
cooling.
The terminal box must have free access to eventual
connections to the output terminals.
The figure below shows a typical alternator installation
with the truck:
Figure 5.1: Typical alternator installation

5.2 DRIVE

The installation of the drive should be based on
manufacturer's recommendations. The drive must be
able to withstand the maximum speed and the necessary
power from the alternator and its respective transmission.
The driving machine must be provided with a protection
system against overspeed: 2160 rpm – 72 Hz for
alternators of 60 Hz and4320 rpm – 144 Hz for
alternators of 120 Hz.

5.3 ALIGNMENT/LEVELING

The alternator must be perfectly aligned with the driven
machine, especially in cases of direct coupling
An incorrect alignment may damage the bearings, cause
vibration and break the shaft.
One way to achieve a correct alignment is to use dial
gauges placed on each coupling sleeve, one pointed
radially and the other axially. So you can check both the
parallelism deviation, (Figure 5.3) and the concentricity
deviation (Figure 5.2), when turning the shafts a full
revolution. The dial gauges must not exceed the reading
of 0.05 mm. If the operator is sufficiently skilled, he can
obtain alignment conditions with a clearance gauge and a
steel ruler, provided that the sleeves are perfect and
centered. (Figure 5.4). A measurement at 4 different
points of the circumference should not give a difference
bigger than 0.03 mm.
Figure 5.2: Radial clearance (concentricity)
16 l 10258257 - Installation, Operation and Maintenance Manual
Figure 5.3: Angular clearance (parallelism)
Figure 5.4: Axial clearance
In alignment/leveling, the different expansion of the
coupled machines must be considered, which can mean
a change in the alignment/leveling during machine
operation.
There are instruments that perform the alignment using
visible laser beam and by specific computer programs
that ensure high reliability and accuracy in alignment of
machines.
NOTE
Bolts, nuts and washers can be supplied with
the alternator upon request

5.4 COUPLING

5.4.1

Direct coupling

Only proper couplings must be used, designed to
transmit torque only, without generating transversal
loads. The shaft centers need to be in a single line, for
elastic coupling as well as for rigid couplings between the
alternator and the driving machine.
The elastic coupling is intended only to compensate
vibrations and not to compensate small assembly flaws.
The coupling must be assembled or removed with the aid
of proper devices and never by means of rudimentary
tools (hammer or mallet).
5.4.2

Coupling by means of pulleys and belts

When a speed ratio is necessary, the drive by belt is the
most commonly used. The diameter of the pulley should
not be less than 2/3 of the alternator frame diameter. The
width of the pulley should not exceed the length of the
shaft end. The maximum diameter is limited by the weight
and allowable peripheral speed. The peripheral speed for
V-belts is 33m/s.
Axial clearance