Tightening Torques; Earthing; Preliminary Controls; Control Of Electrical Insulation - Sincro FB Serie Manuel D'instruction Et De Maintenance

6.2.6 Tightening torques

For previous assembling procedures, follow this table with
the tightening torques :
TIGHTENING TORQUES (Nm)
Dhread Electrical
diameter connections
M5
M6
M8
M10
M12
M16
For mechanical connections it is recommended to use
screws at least class 8.8

6.3 Earthing

The generator housing has to be soundly connected to earth
on the base of the generating set. If flexible antivibration
dampers are mounted between the generator housing and
its base, an earth conductor should be connected in parallel
through the flexible support and be adequately sized (usually
half of the section of the main line cables).
Make sure the earthing procedure is carried
!
out properly.
WARNING!

6.4 Preliminary Controls

6.4.1 Control of electrical insulation

Before starting up the generating set or after long shutdowns
check the insulation resistance of the windings to earth.
Disconnect the AVR before carrying out
this test.
CAUTION!
The results must be over 2MOhm. If this is not the case,
the alternator alone should be oven dried at 60 ÷ 80°C
for 3 hours. Before carrying out this operation remove the
voltage regulator. As an alternative to oven drying hot air at
60 ÷ 80°C can be blown through the alternator for at least
1 hour.
Mechanical
connections
(mat . 8.8)
3 6
5 9
10 23
14 45
20 80
40 200
The windings are tested under high voltage
during production. Additional high voltage
tests can weaken the insulation thereby
IMPORTANT!
reducing the working lifespan. If a high
voltage test should prove necessary for customer
approval, these tests should be carried out at lower
voltages.

6.4.2 Direction of rotation

All machines are equipped with a propeller fan and can
therefore operate in both directions of rotation. The generator
is supplied with clockwise rotation, viewed from the coupling
side (unless otherwise specified on order) to produce a U-
V-W phase sequence (according to IEC 60034-8). If rotation
has to be reversed after delivery ask the Sincro Technical
Office for the relevant wiring diagrams.

6.4.3 Control of voltage and frequency

Control that the voltage and frequency levels required by
the generating set correspond to the generator data plate.
The generator leaves the production line
with a star-series connection (unless
otherwise specified on order) which are
WARNING!
used as reference for its nominal data.
To change connection consult the diagrams in the
appendix of this manual.
All changes in connection must be carried
out solely by a qualified specialist.
WARNING!

6.4.4 AVR board settings

The various generator parameters are
factory set before testing: so no further
adjustments on the machine should be
WARNING!
necessary; in the event that the covers
need to be removed for the adjustments and live
electrical contacts are left bare, it is important that
this operation be carried out solely by qualified
specialists in electrical plant maintenance.
To select the AVR settings access the control board after
removing the cover. Most adjustments are factory set
to ensure satisfactory results in the operating tests on
commissioning. Further adjustments may be necessary
to ensure optimum operation under specific working
conditions.
ENGLISH
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