Balancing; Installation Conditions; Alignment; Electrical Connection - MarelliMotori M8B 250 Instrucciones Y Advertencias De Seguridad

3.3. Balancing

Unless otherwise indicated the rotor is balanced dynamically with a half-key fitted on the shaft extension, in compliance with IEC 34-14.

3.4. Installation conditions

Install the generator in a ventilated room. If installed in closed areas the alternators should have a possibility to exchange the cooling air
directly with atmosphere. Air outlet and inlet openings should not be obstructed: provisions should be taken to prevent obstacles from
obstructing ventilation openings. The inlet of warm air should be avoided.
Provision should be taken to make inspection and maintenance easy when the generator is installed or during operation.

3.5. Alignment

Carefully align the generator and the driving machine.
Inaccurate alignment may lead to vibrations and damage of the bearings.
It is also necessary to verify that the torsional characteristics of generator and driving machine are compatible. In order to allow
torsional analysis calculation (at customer's charge); MarelliMotori can provide rotor drawings for torsional analysis purposes.
For single bearing generators it is further necessary to verify all dimensions of the flywheel and flywheel housing. Furthermore it is
necessary to check the dimensions of the coupling and of the flange on the generator.

3.6. Electrical connection

Standard generators are supplied with 12 leads (9 terminals). Terminals arrangement permits star series and star parallel connection:
it is anyway necessary, when changing the connection from star series to star parallel, to check and modify the connection to the
voltage regulator, according applicable diagrams.
Internal connection diagrams are shown last pages for standard generators (12 leads, with AVR only).
Diagrams with optional excitation devices (Varicomp) are also included.
The output cables have to be fixed to the terminal board as indicated in the following figure.
Direction of rotation
Generators are normally supplied to operate correctly when rotating clockwise (looking from shaft end side).
Grounding
Inside the terminal box there is a terminal for grounding, and a second terminal is on a foot of the generator. Grounding has
to be carried out using a copper wire of suitable size, in compliance with applicable standards.

3.7. Commissioning

Before starting up check insulation resistance:
THE GENERATOR HAS NOT TO BE OPERATED IF INSULATION RESISTANCE IS BELOW 5 MEGAOHM
Before first starting up, check:
- If fixing bolts are securely fixed
- that the alignment and coupling is correct
- that the ventilation air is sufficient
- that the protection grids are in place
- for single bearing generators, that the bolts of the disks are fixed with the correct torque.
Electrical checks
Verify that
- the plant is provided with the correct electrical protection devices, according to applicable standards
- that the connection to the terminal block is correctly performed (bolts of terminals properly tightened)
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