Dismantling; Tightening Torques; Connections And Earthing; Preliminary Controls - Sincro DC Série Manuel D'utilisation Et De Maintenance

6.2.3 Dismantling

For dismantling follow in reverse the instructions given at
assembly sections.

6.2.4 Tightening torques

For mechanical connections it is recommended to use
screws class 8.8.
The tightening torques are shown in the following table:
TIGHTENING TORQUES (Nm)
Electrical
Screw Type connections
Brass
M5
M6
M8 10
M10 14
M12 20
M16 40

6.3 Connections and earthing

Electrical connections have to be done with cables with
sections suitable for the nominal current values and
distances.
Incorrect cables or connections not properly
done, can cause dangerous overheating.
WARNING!
Refer to following drawing:
The generator housing has to be 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
the section of the main line cables).
By the feet on the housing there is are two threaded holes
for the earthing of the housing (see figure).
Make sure the earthing procedure is carried
out properly.
WARNING!
22
Mechanical
connections
Steel (8.8)
3 6
5 10
25
49
85
210
EARTHING POSITION

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 (voltage regulator)
before carrying out this test.
CAUTION!
The results must be over 2 MOhm. If this is not the case,
the alternator alone should be oven dried at 80 - 100°C
for 6 hours.
Before carrying out this operation remove the voltage
regulator.
The windings are tested under high voltage
during production. Additional high-voltage
tests can weaken the insulation thereby
reducing the working lifespan. If a high-
IMPORTANT!
voltage test should prove necessary for
customer approval, these tests should be
carried out at lower voltages.

6.4.2 Control of voltage

Control that the voltage values required by the generating
set correspond to the generator data plate.