3.1 Safety advice
The
openings, lifting eyes and hoisting lugs on the base-plates are used for
transporting the machine sets. The sets must not be lifted by attaching ropes
to the individual machines. Take account of the carrying capacity of these
hoisting devices.
Individual
machines must only be suspended on the main lifting lugs or recesses. The
hoisting gear used must be designed in
accordance with the weight. Use suitable rope guiding or spreading devices for
avoiding damage to machine-mounted accessories.
Auxiliary
lifting lugs, e.g. on fan cowls, top-mounted heat exchanges etc, are not
designed for carrying the machine weight. They are only suitable for lifting
the respective individual part during dismantling and assembly.
3.2 Storage and
conditions
The
generator and accessories must be stored in the proper manner until they are
installed, and protected against moisture, dirt, various chemical substances,
living creatures liable to cause damage and all other kinds of extraneous
influence. If the generator is contained inside a shopping crate, is must be
removed there from.
The
store-houses have to be clean, dry, closed and free of vibration. The
temperature should not drop under +5°c.
3.3 Checks during
storage
If
the machine is stored for longer than three months, the insulation resistance
and the preservative coatings must be checked. If the insulation resistance
falls below the value specified in section 4.3.1, Table 1, the generator must
be dried immediately.
4. Mounting and
operation
Strictly
observe the "General safety instructions" in Section 1.2 regarding
the permissible use of the machines, as well as the special knowledge required
for carrying out work on power installations.
Covers
to prevent accidental contact with live or rotating parts, and those required
for proper air guidance and thus effective cooling should not be opened during
operation.
An
appropriately designed control and speed monitoring device must ensure that no
higher speeds are attained than those permitted according to the rating plate.
4.2 Preparation
4.2.1 General visual
inspection of the machine
The
generator must be subjected to a thorough visual inspection before it is
mounted, to ensure that it has not suffered any damage in transit or storage.
Any defects which are detected must be notified to the supplier or shipping
agent and remedied expertly.
The
condition of the insulation must be checked.
4.2.2 Position
The
generator must be positioned so that the terminal box, the bearings and the
accessories are easily accessible.
4.2.3 Mounting
The
generator must be mounted on a firm foundation. The feet must be mounted on a
level metal base. The supporting surfaces must be carefully packaged if
necessary, to ensure that the stator frame is not deformed.
4.2.4 Cooling
The
room containing the generator must be sufficiently large and well-ventilated.
Steps must be taken to ensure that the generator does not take in the hot air
exhausted by other machines.
CAUTION:
Temperature up to and exceeding 100°C may arise under unfavourable operating
conditions on the frame parts so that touching should be prevented or avoided
in this case. Temperature-sensitive parts such as normal cables or electronic
components should not be in contact with or mounted to these hot parts.
4.2.5 Coupling
A
flexible coupling must be used to couple the generator mechanically to the
prime mover. The coupling must be dynamically balanced and capable of
transferring the torque without generating rotary forces that could act on the
generator, the coupling must not transfer any harmful forces or shocks to the
generator.
Before
the coupling is mounted on the generator shaft, the preservative coating must
be removed and the shaft coasted instead with a thin layer of oil. No force
must be used to mount the coupling on the shaft. A fitting device with a thread
corresponding to that of the generator shaft is useful, or alternatively the
coupling can be heated to appropriately 100°C in an oil bath.
An
extraction tool must be used to remove the coupling from the shaft.
The
generator must be aligned with the aid of two dial gauges. It is advisable to
keep well within the tolerances specified by the coupling manufacturer if
possible, as any misalignment will cause an additional load to be placed on the
bearing and the coupling.
4.2.6 Securing the
mechanical position
When
the generator has been mounted and fastened to the base, its position must be
secured so that the shaft alignment cannot be altered during operation. It is
advisable to pin the feet at the base.
4.3 Connections
4.3.1 Insulation
resistance of the winding
The
insulation resistance of the stator winding must be measured before a new
generator or a generator which has been out of service for a long time is put
into operations. If the winding is in perfect condition, its resistance must
not be less than the values specified in Table 4.3.1 a.
WARNING
During and immediately after measuring the terminals may in part carry
dangerous voltages and must not be touched.
Should
any power supply cable be connected, ensure that no system voltage can be applied.
1)
Lowest measurement voltage 100V
The
insulation resistance must be measured for roughly one minute until upper range
value is reached. If the measured resistance is less than the value specified
in the table, the Siemens generator must be dried. If the winding temperature rises by
10°C, the insulation resistance drops by appropriately half. If the temperature
of the winding drops below 5°C, the measured insulation resistance may be
misleading and must not be used to determine the readiness of the equipment for
connection.
4.3.2 Drying
The
simplest drying method is a dry room containing clean air heated ro 80°C and a
steam exhauser. In this case, the generator does not need to be dismantled. If
the generator is designed with a higher degree of protection, e.g. IP 54, the
parts which provide this protection must be removed. The drying time depends on
the amount of moisture.
Other
drying methods:
-Short-circuit
operation
-Heating
with direct current
This
insulation resistance must be measured during the drying process. It drops
abruptly initially and then rises again gradually. The generator is dry when
the insulation resistance reaches the specified value.
If
the insulation resistance of the generator still does not improve after a long
drying period, the low insulation value must caused by another type of fault
and nor by moisture in the stator winding.
The
cables must always be laid to the generator. And the generator connected to the
switching and protective devices, by suitably qualified persons. These persons
must observe the valid specifications and standards in doing so. The cables
must connected correctly and exert neither a tensile nor a flexural stress on
the terminals.
The
cables must be connected in according with the circuit diagram on the inside of
the terminal box cover. The terminal screws must be properly tightened, so that
they cannot be heated up and loosened during operation as a result of a contact
resistance.
The
terminals box must be closed after the connections have been made.
4.3.3 Fuse protection
The
generators must be protected by means of fuses which are suitable for the rated
current specified on the rating plate.
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