Technical
Characteristics
2.1 - Electrical characteristics
This alternator is generator
without slip rings and revolving field brushes, wound as “2/3 pitch”; 12-wire,
with class H insulation and a field excitation system available in either SHUNT
or AREP version.
In order to conform to standard
EN 61000-6-3, EN 61000-6-2, EN 55011, the R 791 interference suppression kit is
needed.
Electrical options
- Stator temperature detection
probes.
- Space heaters.
2.2 -
Mechanical characteristics
- Steel frame
- End shields in cast iron
- Greasable ball bearings
- Mounting arrangement
MD 35: single bearing with
standard feet and SAE flanges/coupling discs.
B 34: two-bearing with SAE flange
and standard cylindrical shaft extension.
- Drip-proof machine, self-cooled
Mechanical
options
- Direct power output by (non
reconnectable) cables, regulator fitted outside the alternator.
- Protection against harsh environment.
- Air input filter, air output
labyrinth cowling. Alternators fitted with air inlet filters should be derated
by 5% (power).
To prevent excessive temperature
rise caused by clogged filters, it is advisable to fit the stator winding with
thermal sensors (PTC).
3 -
INSTALLATION
Personnel undertaking the various
operations indicated in this section must wear personal protective equipment
appropriate for mechanical and electrical hazards.
3.1 –
Assembly
All mechanical handling
operations must be undertaken using suitable equipment and the machine must be
horizontal. Check how much the machine weighs (see 4.8) before choosing the
lifting tool.
During this operation, do not
allow anyone to stand under the load.
Handling
The generously-sized lifting
rings are for handling the alternator alone. They must not be used to lift the
genset. The choice of lifting hooks or handles should be determined by the
shape of these rings. Choose a lifting system which respects the integrity and
the environment of the machine.
During this operation, do not
allow anyone to stand under the load.
WARNING
After handling the machine using
the lifting ring, snap on the plastic cover provided in the maintenance manual
wallet.
Single-bearing coupling
Before coupling, check the
compatibility between the alternator and the engine by performing:
- undertaking a torsional
analysis of the transmission (alternators data are available on request),
- checking the dimensions of the
flywheel and its housing, the flange, coupling discs and offset.
WARNING
When coupling the alternator to
the prime mover, do not use the fan to turn the alternator or rotor.
The holes of the coupling discs
should be aligned with the flywheel holes by cranking the engine.
Make sure the machine is securely
bedded in position during coupling. Check that there is lateral play on the
crankshaft.
Double-bearing coupling
- Semi-flexible coupling
Careful alignment of the machines
is recommended, checking that the lack of concentricity and parallelism of both
parts of the coupling do not exceed 0.1 mm.
This alternator has been balanced
with a 1/2 key.
Location
The room where the alternator is
placed must be ventilated to ensure that the ambient temperature cannot exceed
the data on the nameplate.
3.2 - Checks
prior to first use
• Electrical
checks
Under no circumstances should an
alternator, new or otherwise, be operated if the insulation is less than 1
megohm for the stator and 100,000 ohms for the other windings.
There are 2 possible methods for
restoring the above minimum values.
a) Dry out the machine for 24
hours in a drying oven at a temperature of 110 °C (without the regulator).
b) Blow hot air into the air
intake, having made sure that the machine is rotating with the exciter field
disconnected.
Note : Prolonged standstill
In order to avoid these problems,
we recommend the use of space heaters, as well as turning over the machine from
time to time. Space heaters are only really effective if they are working
continuously while the machine is stopped.
Ensure that the alternator has
the degree of protection matching the defined environmental conditions.
When the alternator’s power
output is ensured directly through cables, these must be connected before
start-up.
Mechanical
checks
Before starting the machine for the
first time, check that:
- all fixing screws are tight,
- the length of screw and the
tightening torque are correct,
- the cooling air is drawn in
freely,
- the protective grilles and housing
are correctly in place,
- the standard direction of
rotation is clock-wise as seen from the shaft end (phase rotation in order 1 -
2 - 3).
For anti-clockwise rotation, swap
2 and 3.
- the winding connection
corresponds to the site operating voltage (see section 3.3).
3.3 - Terminal
connection diagrams
To modify the connection, change
the position of the stator cables on the terminals. The winding code is
specified on the nameplate.
Any intervention on the
alternator terminals during reconnection or checks should be performed with the
machine stopped.
In no case should the internal
connections in the terminal box be subjected to stresses due to cables
connected by the user.
Electrical installations must
comply with the current legislation in force in the country of use.
Check that:
- The residual circuit-breaker
conforms to legislation on protection of personnel, in force in the country of
use, and has been correctly installed on the alternator power output as close
as possible to the alternator. (In this case, disconnect the wire of the
interference suppression module linking the neutral).
- Any protection devices in place
have not been tripped.
- If there is an external AVR,
the connections between the alternator and the cabinet are made in accordance
with the connection diagram.
- There is no short-circuit
phase-phase or phase-neutral between the alternator output terminals and the
generator set control cabinet (part of the circuit not protected by circuit
breakers or relays in the cabinet).
- The machine should be connected
with the busbar separating the terminals as shown in the terminal connection
diagram.
- The alternator earth terminal
inside the terminal box is connected to the electrical earth circuit.
- The earth terminal is connected
to the frame.
The connections inside the
terminal box must never be subjected to stress due to cables connected by the
user.
3.4 –
Commissioning
The machine can only be started
up and used if the installation is in accordance with the regulations and
instructions defined in this manual.
The machine is tested and set up
at the factory. When first used with no load, make sure that the drive speed is
correct and stable (see the nameplate). With the regreasable bearing option, we
recommend greasing the bearings at the time of commissioning (see section 4.3).
On application of the load, the
machine should achieve its rated speed and voltage; however, in the event of
abnormal operation, the machine setting can be altered (follow the adjustment
procedure in section 3.5). If the machine still operates incorrectly, the cause
of the malfunction must be located (see section 4.5).
3.5 -
Setting up
The various adjustments during
tests must be made by a qualified engineer. Ensure that the drive speed
specified on the nameplate is reached before commencing adjustment.
After operational testing,
replace all access panels or covers.
The AVR is used to make any
adjustments to the machine.
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