Guide to Install Diesel Generator Set Cables and Wires
by Starlight Generator dieselgeneratortechI
Line tube
1.
The line pipe should be selected according to local regulations.
2.
The surface laid pipe should be supported and fixed, and the pipe must be
grounded.
3.
The pipeline system should be laid before the cable is introduced. At least 40%
of the space should be in the conduit. The radius of the bend of the elbow
should not be less than 2.5 times the outer diameter of the conduit.
4.
The brigade system should be able to prevent the ingress of dust and water.
Vents shall be designed at the highest and lowest points of the pipeline, and
the open-disposed piping shall be composed of good fireproof materials.
II
Trunking
1.
Steel trunking should follow the relevant regulations.
2.
Make sure that there is sufficient bending radius when installing. As with
steel conduits, the use of steel trunking as a protective material for
conductors is in accordance with the relevant wiring rules, but cannot be used
for combustion protection.
3.
At least 45% of the space in the trunking, the trunking should have the correct
support and fixing points.
4.
The trunking cover should not be placed on the underside of the wire trough.
When passing through walls, floors and ceilings, the trough cover should be
tight. The vertically arranged wire trough should have a suitable
heat-resistant material inside to prevent the temperature in the top region
from being too high.
III
Line isolation
Separation
measures should be taken for different line cables to prevent electrical and
physical contact. There are three types of lines defined in the specification:
1.
Low voltage line powered by mains (except for fire or emergency lighting).
2.
Ultra-low voltage or communication lines (such as telephone, address and data
transmission systems) powered by a safe power source.
3.
Fire alarm or emergency lighting.
IV
Cable tray
1.
The most common method is to lay the cable on the perforated cable reel. The
cables are arranged flat and the maximum fastening distance is 450 mm.
2.
The support spacing of the support of the cable drum is typically 1200 mm. The
cable reel should have sufficient strength and should be selected to have an
additional cable capacity close to 25% of the load carrying cable.
V
Cable trench
1.
Cable trenches in generator rooms and equipment rooms should be enclosed (with
concrete or tiled iron panels).
2.
Cable trenches should be constructed with the smallest possible bend radius for
the largest cable.
3.
The cable trench is as straight as possible, and its surface is smooth and has
a slope so that water and oil can be drained to the sump.
VI
Underground laying
1.
Armored shielded cables can be laid directly underground and should have a 75
mm thick implant. The distance between the high and low voltage cables in the
cable trench or only underground is between 160 mm and 400 mm.
2.
When passing through a road, passage or building structure, the cable should be
protected from mechanical damage by conduit or guards. Reserve a certain amount
of space for future cable laying.
What
are the precautions for the connection of diesel generator set wires?
The
power line connection of the diesel generator set output to the load should be
carried out by a qualified and experienced electrician, as well as repair and
maintenance. In addition, the wiring of the unit must comply with the relevant
electrical or other requirements, including grounding and ground fault
protection requirements. The following is a detailed introduction to the
connection precautions for the diesel generator set wires.
Wiring
Due
to the vibration of the generator, the connecting generator should use a
flexible wire so that when the generator is displaced, the connection column of
the alternator or the power air switch is not damaged. If the flexible wire
cannot be used due to installation problems, the generator can be used nearby.
A junction box is installed, and a section from the box to the machine is
connected by a flexible cord. The wiring should be placed on the pipeline or
the trunking and must not be fixed on the generator set. If the wires need to
be bent, please refer to the minimum bending radius.
The
wires must match the voltage and current output from the generator. Before
determining the thickness of the wire, it is necessary to consider the indoor
temperature, the installation method and other wires side by side. When using
single-core copper wire, the sealing sheath should be made of non-magnetic
metal such as aluminum or copper, or non-metal. If a magnetic metal sheath is
used, JC's method is to cut the gap in the sheath to ensure that the current
does not generate eddy currents.
All
interfaces must be checked for firmness. Whether the phase is the same as the
mains, this is especially important when using the automatic switch or when the
unit is used as a parallel.
Protection
The
connection generator and load are protected by a disconnect switch that
automatically disconnects the circuit during overload or short circuit.
Load
When
designing the power supply system, ensure that the load is balanced. Do not
load the one phase far more than the other, which will cause the coil of the
alternator to overheat.
Phase
and phase imbalances can also damage sensitive three-phase equipment connected
to the consumer system. Make sure that the current of one phase is not exceeded
by the current of the generator. If it is necessary to connect the unit to the
existing power supply branch, it must be considered for redistribution in order
to balance these loads.
Power
Factor
The
power factor (COS) of the load must be calculated on the design. If the power
factor is below 0.8 hysteresis (inductance), the generator will be overloaded.
The most smooth operating power factor of the output of this unit is 0.8-1.
Pay
particular attention to the presence of advanced power factor when installing
automatic or manual power factor correction devices such as capacitors. This
will result in voltage instability and destructive ultra-high voltages. In
general, all power factor correctors are turned off when the generator is
supplying power.
Grounding
requirements
1.
The grounding requirements are determined by different regions. The base of the
machine must be absolutely grounded. Because the generator is equipped with a
shock absorber, the grounding wire should be retractable to prevent
disconnection due to vibration.
2.
The grounded wire or clamp can pass the generator full load current and meet
local specifications.
3.
Alternator reconnection
Most
alternators can be rewired to accommodate different output voltages. Refer to
the (Alternator Manual) for any additional voltages, such as power-off
switches, current exchangers, and wires, before changing the voltage. Ammeters
and more.
Parallel
operation
Special
equipment is required when standard generators are combined or connected to the
grid.
After
installing the generator, do not rush to start, first check the resistance of
the coil. The automatic regulator should be disconnected, the rotating diode
can be temporarily shorted by wires, or disconnected first, and all controlled lines
must be disconnected.
Use
a 500V megger or similar instrument to disassemble the wire between the
midpoint and ground. Measure the impedance from the terminal to ground. The
insulation resistance of the machine to ground should exceed 5MΩ, and the coil
must be processed.
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Created on Aug 4th 2019 20:12. Viewed 355 times.