Safety Advice of Siemens Generator
by Starlight Generator dieselgeneratortech3.1 Safety advice of
Siemens generator
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 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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Created on Feb 15th 2019 21:16. Viewed 386 times.