Teknik Sipil

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Teknik sipil adalah salah satu cabang ilmu teknik yang mempelajari tentang bagaimana merancang, membangun, merenovasi tidak hanya gedung dan infrastruktur, tetapi juga mencakup lingkungan untuk kemaslahatan hidup manusia.

Teknik sipil mempunyai ruang lingkup yang luas, di dalamnya pengetahuan matematika, fisika, kimia, biologi, geologi, lingkungan hingga komputer mempunyai peranannya masing-masing. Teknik sipil dikembangkan sejalan dengan tingkat kebutuhan manusia dan pergerakannya, hingga bisa dikatakan ilmu ini bisa merubah sebuah hutan menjadi kota besar.

Cabang-cabang ilmu teknik sipil

• Struktural: Cabang yang mempelajari masalah struktural dari materi yang digunakan untuk pembangunan. Sebuah bentuk bangunan mungkin dibuat dari beberapa pilihan jenis material seperti baja, beton, kayu, kaca atau bahan lainnya. Setiap bahan tersebut mempunyai karakteristik masing-masing. Ilmu bidang struktural mempelajari sifat-sifat material itu sehingga pada akhirnya dapat dipilih material mana yang cocok untuk jenis bangunan tersebut. Dalam bidang ini dipelajari lebih mendalam hal yang berkaitan dengan perencanaan struktur bangunan, jalan, jembatan, terowongan dari pembangunan pondasi hingga bangunan siap digunakan.

• Geoteknik: Cabang yang mempelajari struktur dan sifat berbagai macam tanah dalam menopang suatu bangunan yang akan berdiri di atasnya. Cakupannya dapat berupa investigasi lapangan yang merupakan penyelidikan keadaan-keadaan tanah suatu daerah dan diperkuat dengan penyelidikan laboratorium.

• Manajemen Konstruksi: Cabang yang mempelajari masalah dalam proyek konstruksi yang berkaitan dengan ekonomi, penjadwalan pekerjaan, pengembalian modal, biaya proyek, semua hal yang berkaitan dengan hukum dan perizinan bangunan hingga pengorganisasian pekerjaan di lapangan sehingga diharapkan bangunan tersebut selesai tepat waktu.

• Hidrologi: Cabang yang mempelajari air, distribusi, pengendalian dan permasalahannya. Mencakup bidang ini antara lain cabang ilmu hidrologi air (berkenaan dengan cuaca, curah hujan, debit air sebuah sungai dsb), hidrolika (sifat material air, tekanan air, gaya dorong air dsb) dan bangunan air seperti pelabuhan, irigasi, waduk/bendungan(dam), kanal.

• Teknik Lingkungan: Cabang yang mempelajari permasalahan-permasalahan dan isu lingkungan. Mencakup bidang ini antara lain penyediaan sarana dan prasarana air besih, pengelolaan limbah dan air kotor, pencemaran sungai, polusi suara dan udara hingga teknik penyehatan.

• Transportasi: Cabang yang mempelajari mengenai sistem transportasi dalam perencanaan dan pelaksanaannya. Mencakup bidang ini antara lain konstruksi dan pengaturan jalan raya, konstruksi bandar udara, terminal, stasiun dan manajemennya.

• Informatika Teknik Sipil: Cabang baru yang mempelajari penerapan Komputer untuk perhitungan/pemodelan sebuah sistem dalam proyek Pembangunan atau Penelitian. Mencakup bidang ini antara lain dicontohkan berupa pemodelan Struktur Bangunan (Struktural dari Materi atau CAD), pemodelan pergerakan air tanah atau limbah, pemodelan lingkungan dengan Teknologi GIS (Geographic information system).

Keluasan cabang dari teknik sipil ini membuatnya sangat fleksibel di dalam dunia kerja. Profesi yang didapat dari seorang ahli bidang ini antara lain: perancangan/pelaksana pembangunan/pemeliharaan prasarana jalan, jembatan, terowongan, gedung, bandar udara, lalu lintas (darat, laut, udara), sistem jaringan kanal, drainase, irigasi, perumahan, gedung, minimalisasi kerugian gempa, perlindungan lingkungan, penyediaan air bersih, survey lahan, konsep finansial dari proyek, manajemen projek dsb. Semua aspek kehidupan tercangkup dalam muatan ilmu teknik sipil.

Perbedaan dari arsitek, terletak pada posisi ahli teknik sipil dalam sebuah proyek. Arsitek menyumbangkan rancangan, ide, kemungkinan pelaksanaan pembangunan di atas kertas. Hasil rancangan tersebut diserahkan selanjutnya kepada staf ahli bidang teknik sipil untuk pelaksanaan pembangunan. Tahapan ini, ahli teknik sipil melakukan perbaikan/saran dari pelaksanaan perencanaan, koordinasi dalam proyek, mengamati jalannya proyek agar sesuai dengan perencanaan. Selain itu, ahli teknik sipil juga membangun konsep finansial dan manajemen proyek atas hal-hal yang mempengaruhi jalannya proyek.

Ahli teknik sipil tidak hanya berurusan dengan pembangunan sebuah proyek bangunan, tetapi di bidang lain seperti yang berkaitan dengan informatika, memungkinkan untuk memodelisasi sebuah bentuk dengan bantuan program CAD, pemodelan kerusakan akibat gempa, banjir. Hal ini sangat penting di negara maju sebagai tolak ukur kelayakan pembangunan sebuah bangunan vital yang mempunyai risiko dapat menelan korban banyak manusia seperti reaktor nuklir atau bendungan, jika terjadi kegagalan perencanaan teknis. 

Rancangan bangunan tersebut biasanya dimodelkan dalam komputer dengan diberikan faktor-faktor ancaman bangunan tersebut seperti gempa dan keruntuhan struktur material. Peran ahli teknik sipil juga masih berlaku walaupun fase pembangunan sebuah gedung telah selesai, seperti terletak pada pemeliharaan fasilitas gedung tersebut.

Read More - Teknik Sipil

Practical Basis of Design

In distribution system studies, particularly where growth and expansion
are contemplated, several plans are usually taken under consider-
ation. For purposes of comparison, design voltage-drop limits are determined
beforehand, and these same limits are used in all of the studies. Comparable
layouts are made to provide adequate voltages and suitable equipment
loadings with the design loads. A light-load voltage profile is assumed
to fall within permissible limits, although regular changes at the substation
may be relied upon to maintain maximum permissible voltage at
the first customer.

The utilization voltage spread of 15 V, the estimated service and
customer wiring voltage drops, and contact-making-voltmeter (voltageregulating
relay) bandwidth setting are derived from industry standards
accepted for the design of utilization devices.

Distribution circuit is a rather long and tedious process. A method for
making calculations easily and providing a record of basic data employs
a system of “unit voltage drops”; a self-explanatory data form
also indicates the procedure for making the computations.
For convenience, the unit selected for the voltage-drop calculations
may be 10,000 kVA-ft, that is, 10 kVA at a distance of 1000 ft
or 100 kVA at a distance of 100 ft, etc.

Circuit loads are assumed distributed in proportion to the connected transformers except where
relatively large individual loads are known, in which case equivalent
transformer capacity is estimated on the basis of known demands.
Included with the calculations is a sketch of the existing and
proposed circuit with station numbers for each branch, transformer or
group of transformers, or wire size change; these correspond to numbers
on the calculation sheet. Factors for each wire size to convert from
percent voltage drop to percent kilowatt loss in some smaller
branches are neglected to simplify calculations,
but results are sufficiently accurate for purposes of comparison.

In making comparisons, evaluation of losses should include both
a demand component reflecting system investment and an energy
component. Also, costs of conversion reflecting both additional capital
investment and annual operating and maintenance expenses should be
taken into account. All of these values are different for each utility.

Read More - Practical Basis of Design

Street Lighting

Street lighting may be supplied from either series or multiple circuits.
Series circuits and lamps have been extensively used in the past
and many such systems are still in operation. Multiple supply, however,
has been used almost exclusively in later installations, especially with
the development of economical light-sensitive control devices, which has
made practical the connection of such lighting to the same secondary
mains that also supply other types of customers.

Multiple Circuits
Multiple street lighting is usually served from secondary mains
at normal utilization voltages. The secondary may be a separate circuit
serving only street lighting loads, or part of the secondary circuit supplying
other customers. The former may have controls exclusive to the
circuit, while the latter may have individual controls for individual
lamps or groups of lamps. As mentioned earlier, such circuits may be
controlled from a variety of relays, some actuated from series street
lighting circuits. Photocells, activated by the light intensity of the ambient,
and connected between the secondary supply and the streetlight,
have proven economical and desirable, as they simplify controls, eliminating
additional wires and improving the appearance of overhead
lines.

The principal advantage of multiple supply is the use of the secondary
distribution systems, with only minor effects on transformer
load and voltage conditions; additional advantages include greater
safety because of the low voltages involved as well as lower handling
and installation costs, as the equipment used is essentially that in use
on distribution circuits. In most instances, separate lightning or surge
arresters are not required.

Series Circuits
As the name denotes, lamps in the series type of circuit are connected
in series and supplied from a constant-current transformer; the
usual current output rating is 6.6 A, with the outgoing voltage varying
with the load connected. The light output for different-sized lamps at
this fixed current rating depends on the length of the filament; for larger-
size lamps operating at 15 or 20 A, the filaments are also of heavier
cross section in order to carry the greater current safely. Series lamps
often are rated in lumens, the unit of light flux, while the wattage may
vary with the size of the lamp. Lamp efficiency is expressed in lumens
per watt, with 600-lm lamps operating at 6.6 A requiring about 43 W
while 6000-lm lamps require approximately 320 W. Light efficiency is
further increased with reflectors and refractors.

Advantages of series circuits include high efficiency for a widely
distributed load, the ability to use a high-voltage and low-current supply
that permits long lengths of relatively small-size conductors to be
used with low loss and small voltage drop, and the ability to keep the
variation in light intensity at a minimum because of the constant current
value at each lamp. Disadvantages mainly center around the need
for special transformers and control devices, as well as the need for
separate lightning or surge arresters at the transformer, the switches,
and certain points along an extended circuit.

Constant-current Transformers
To obtain a constant current output from an essentially constant
voltage supply, the two coils of the transformer are so arranged that the
distance between them may be varied. The primary coil, receiving power
at a constant voltage, is fixed in position. The secondary coil is movable
along the common core; its position depends on the load. The secondary
coil is balanced by a weight that reacts proportionally with the repulsion
forces to maintain its output at the rated value.

When the two coils are close together, the magnetic field or flux
produced by the primary interlinks maximally with the secondary coil,
inducing a maximum secondary voltage. The coils act as magnets and
tend to repel each other. As the load on the secondary decreases, the
current in the secondary will tend to increase, increasing the repulsion
between the coils. The secondary coil is raised, decreasing the magnetic
field or flux linking the two coils, thereby decreasing the secondary voltage,
and the current is dropped to its rated value.

The majority of series street lighting circuits are operated without
grounds. When an accidental ground occurs, the circuit is generally not
affected. When a second ground occurs, the lamps between the two
grounds will go out or burn dimly, giving ready indication of the location
of the grounds. In some instances, however, an intentional ground
is placed at mid-circuit. This not only reduces the normal stresses on the
insulation of the several units in the circuit to one-half the voltage of the
ation. For purposes of comparison, design voltage-drop limits are determined
beforehand, and these same limits are used in all of the studies.


Series Lamps
Series lamps are usually rated at 6.6 A. Larger lamps, generally
4000 1m or larger, are supplied at 15 or 20 A through transformers that
supply an individual lamp (referred to as IL transformers) or transformers
that supply several lamps (referred to as SL transformers).
Lamp failure in a series circuit causes a momentary opening of the
circuit and a high voltage at the terminals of the lamp. A film disk cutout,
connected between the terminals of the
lamp, normally acting as an insulator, breaks down and short-circuits the
failed lamp.


Control Devices
Series circuits may be controlled from the substation manually or
through time switches that automatically turn them on and off at predetermined
times; one such switch operates in accordance with the hours
of sunset and sunrise, and is called an astronomical time switch.

Read More - Street Lighting

Fault-Current Calculation

For the proper coordination of protective devices on a distribution
system, it is essential that the magnitude be known of the fault current
which they may be called upon to handle. For dc systems, the calculation
is a relatively simple application of Ohm’s law; for ac systems, the
procedures are more complex, but for most problems, practical solutions
permit simplified procedures.
For ac systems, four general types of faults can be considered: three
phases short-circuited together (with or without a ground), phase to
phase to ground, phase to phase, and single phase to ground.


Actual Fault Current
The actual fault current may be broken into two components, ac
and dc. The simplified equations give values of the ac, or steady-state,
component, which remains constant throughout the duration of the
fault. The value of this current follows Ohm’s law and is equal to the
voltage divided by the impedance of the circuit from the source to the
point of fault.

Standard measurement of the two components is taken at one-half cycle after the start of the fault.
The total (root mean square) fault current is the square root of the sum
of the squares of the two components; this composite rms current is not
symmetric, and is known as the asymmetric current.

The magnitude of the total fault current during the transient period,
therefore, depends on the type of fault and the time of its initiation.
After the transient period, the magnitude of the fault current depends
only on the type of fault.

The time of fault initiation is measured angularly along the voltage
wave, i.e., as a number of degrees from a known point, such as peak voltage
or voltage zero. Since there is usually a phase angle between voltage
and current, a fault will occur at a different point on the current wave.

If it occurs at the ac component peak, maximum transient current
occurs. This dc component is equal to the difference between the instantaneous
values of the ac fault current and the ac load current. Maximum
transient current occurs at the ac component peak, but maximum rms
fault current occurs at voltage zero. The transient component is zero
when the fault occurs at the time the instantaneous values of the load
current and steady-state current are equal. Between the maximum and
zero transient points, a transient component will exist in which the rms
fault current is less than the rms current when the fault occurs at voltage
zero. Since protective devices operate during transient periods, they are
designed to interrupt the maximum possible fault current.

Factors of Asymmetry
As the reactance to resistance ratio (X/R) and the power factor of
a faulted circuit change, the magnitude of the asymmetric current will
vary with respect to the symmetric current. As this ratio increases and
the power factor decreases, the asymmetric current will increase. A ratio,
known as the factor of symmetry, of the asymmetric to the symmetric
current can be found for different X/R ratios and corresponding power
factors.

When the symmetric current and the X/R ratio are known, the
maximum asymmetric current can be found. This is useful in the design
of fuse cutouts which are rated asymmetrically.

Read More - Fault-Current Calculation

Substations

Location versus Distribution Voltage
Perhaps the first consideration regarding a distribution substation
is its location. In general, it should be situated as close to the load center
to be served as practical. This implies that all loads can be served
without undue voltage regulation, including future loads that can be
expected in a reasonable period of time. The difficulty in obtaining substation
sites is an important factor in selecting the distribution voltage,
both in original designs and in later conversions.

The higher the distribution voltage, the farther apart substations
may be located, but they also become larger in capacity and in the number
of customers served. Thus, the problem of the number and location
of distribution substations involves not only the study of transmission
and subtransmission designs, but more emphasis on service reliability
and consideration of additional costs that may be justified. The subjects
of sectionalizing, field-installed voltage regulators and reclosers, capacitors,
and ties to adjacent sources are discussed elsewhere, but are pertinent
to the problem.

Supply Feeders and Circuit Breaker Requirements
The number and sources of supply subtransmission feeders to the
distribution substation will depend not only on the load to be served,
but also on the degree of service reliability sought. Some rural substations
may be supplied from only one subtransmission feeder, while
substations serving urban and suburban areas have a minimum of two
supply feeders and may have several more. Each additional incoming
feeder, however, adds to the bus and switching requirements, including
auxiliary devices for their protection, all of which add to costs.

Circuit Breaker Arrangements
Some basic arrangements of incoming high-voltage circuit breakers
and transformers are shown in Figure 4-8. Each scheme progressively
adds to the reliability of service to the substation and the loads it supplies.

For example, in scheme a, a failure on the transmission line or
substation transformer or bus will trip the breaker back at the transmission
source, and service may not be restored until the fault is found and
repaired; in scheme b, such failures will trip the circuit breaker but service
can be restored as soon as the fault is isolated; in schemes c, d e, f, and
g (the last incorporating a ring bus), failures on the incoming transmission
lines, transformers, or high-voltage circuit breaker will not interrupt
(except for a short time or momentarily) the supply to the bus serving
distribution feeders.

Since the cost of high-voltage circuit breakers, together
with their accessories, is often as great as or greater than the cost
of the transformers with which they may be associated, it is essential
that the cost of additional circuit breakers not outweigh the protective
advantages gained. It may prove desirable that a minimum number of
circuit breakers be installed initially and others added as deemed necessary
for any improvement in service reliability that time, increments of
load, and customers’ requirements may indicate.


Interrupting Duty
The circuit breakers must not only interrupt the normal load current,
but must be mechanically able to withstand the forces resulting
from the large magnetic fields created by the fault current flowing
through them. Since the field will depend on the magnitude of the fault
current, which in turn also depends on the voltage of the circuit, the
stresses that must be accommodated depend on both of these values.
A circuit breaker, therefore, is rated not only on its applied voltage and
normal current-carrying capacity, but on its interrupting ability, expressed
in volt-amperes (or kVA or MVA); for example, 100-A, 35-kV, or
50,000-kVA interrupting “duty” or capability.
Insulation Coordination—BIL
Circuit breakers and other equipment are subject to high-voltage
surges resulting from lightning or switching operations, and the insulation
of their energized parts must be capable of withstanding them.
Lightning or surge arresters are installed on the conductors and buses
of each phase as close to the circuit breakers as practical, with the intent
of draining off the voltage surge to ground before it reaches the
breaker.

To provide adequate insulation economically and to restrict and
localize possible damage to the circuit breaker, the insulation provided
for the several parts is coordinated. Internal parts are insulated as
equally as practical, but their insulation is generally stronger than that
of the bushings, which in turn is stronger than that of the “discharge”
point of the associated arrester. Thus, a surge not drained to ground
by the arrester will next tend to flash over at the bushings, outside
the tank, where damage would be confined, comparatively light, and
easier to repair. In general, the insulation of the weakest point in the
circuit breaker should be weaker by such a margin as to ensure it will
break down before the insulation of the principal equipment it is protecting.

The coordination of insulation requires the establishment of a basic
insulation level (BIL) above which the insulation of the component parts
of the system should be maintained, and below which lightning or surge
arresters and other protective devices operate. This is discussed further
in connection with protective devices.
Substation transformers also have their insulation coordinated with
that of associated circuit breakers, buses, and other devices.

Capacitors
As mentioned earlier, banks of capacitors may be connected to the
high-voltage incoming bus in connection with voltage regulation and
increasing the capacity or capability of the substation to supply load.
All or portions of these banks may be switched on and off to provide
flexibility in maintaining voltage regulation and power factors. This is
done with one or more circuit breakers, and arresters or other protective
devices as indicated.

Transformers
Substation transformers may consist of three-phase units or banks
of three single-phase units. The size of these individual installations may
range from 150 kVA (three-phase) in small rural stations to upwards of
25,000 kVA at larger urban and suburban substations. Their impedances
are generally low, restricting unregulated voltage variations at the bus
to a few percent, except where fault current levels are high. In this case,
transformer impedances are increased to limit fault current duty to design
limits.

The impedances of the transformer banks in a station should match
each other as closely as practical to have the banks share the load as
equally as practical.
The transformers may be connected in a delta or wye pattern, on
both the incoming high-voltage (subtransmission) side and the outgoing
low-voltage (primary circuit) side. The transformers are ordinarily
of the two-winding standard type, operating much as the distribution
transformers.

For many reasons, including the random and nonuniform movement
of the molecules in the core of the transformer, the alternating
magnetic field that is set up may be distorted, producing serrated sine
waves on both sides of the transformer. These serrations can be broken
down into a series of harmonics or waves with frequencies of 3, 5, 7,
etc., times the basic frequency (usually 60 cycles per second). If the transformers
have a ground on either side, the harmonics or fluctuations flow
to ground and the original sine wave essentially remains undistorted. If
the windings are connected in delta fashion, these fluctuations circulate
around the delta, filtering out the harmonics and eliminating them from
the sine wave formed in the windings; however, they do cause some
unnecessary heating.

Where the transformer windings are connected in a wye arrangement
without a ground or neutral back to the source, the harmonics may
be particularly bothersome. To overcome these, each of the single-phase
transformations (singly or within a three-phase unit) is provided with
a third, small-capacity winding; the three such windings are connected
in delta (even though the main primary and secondary windings are
connected in wye). The delta thus formed allows the harmonics to circulate
within it, producing a little heat but essentially filtering them out,
so that the sine wave produced on both the high and low sides of the
transformer will be a more pure sine wave.

Low-side Bus Arrangements
The low sides of the transformers are connected to their buses
usually through circuit breakers. Several configurations are shown
in Figure 4-9. Some provision is usually made for permitting circuit
breakers, switches, regulators, and other devices to be taken out of
service for maintenance or for other reasons without causing an interruption
to the outgoing distribution feeders. Each of the outgoing
distribution feeders is usually equipped with its own circuit breaker.
The relays operating these, as well as the transformer high-side circuit
breakers, and the capacitors (if any) are coordinated so that only the
proper circuit breaker will operate to clear a fault that may occur on
some portion of the system.

Voltage Regulators
Each distribution feeder may have its voltage individually regulated,
employing three single-phase regulators or one three-phase regulator.
If all of the distribution feeders have approximately the same load
cycles and voltage regulation (even if corrected by capacitors, field regu-
lators, or other means out on the feeder) the bus to which they are connected
may be regulated in place of individual feeder regulators. While
this calls for a certain amount of compromise, it may prove economical
in many instances.

Mobile Substations
Substations are often designed for three single-phase transformers
so that, where they are connected in delta on the incoming side, they can
operate in open delta in the event of failure of one of the units. In some
instances, a spare single-phase transformer is installed at the substation
so that, in the event of failure of one of the transformers, a replacement
can be made readily.

With the advent of lighter transformers and improved transportation
equipment, it has proven practical to mount a three-phase
transformer and associated switching and surge arresters on a trailer
especially designed for that purpose. Such a mobile substation can be
readily transported to a substation where a failure has occurred. The
terminal arrangements of both the mobile substation and the fixed
substation are so designed that often service can be restored more
quickly than by reconnecting the spare unit (which no longer need be
provided).

The mobile substation not only can be effective where the failure
may involve more than one transformer, but can service a number of
substations in a more economical fashion than the installation of spare
transformers at many, if not all, substations. Further, it may also be installed
as a separate, temporary substation, picking up portions of the
load of one or more substations whose facilities may be overloaded.

Read More - Substations

Protective Devices

For the distribution system to function satisfactorily, faults on any
part of it must be isolated or disconnected from the rest of the system as
quickly as possible; indeed, if possible, they should be prevented from
happening. The principal devices to accomplish this include fuses, automatic
sectionalizers, reclosers, circuit breakers, and lightning or surge
arresters. Success, however, depends on their coordination so that their
operations do not conflict with each other.


Fuses
Time-Current Characteristic
A fuse consists basically of a metallic element that melts when “excessive”
current flows through it. The magnitude of the excessive current
will vary inversely with its duration. This time-current characteristic
is determined not only by the type of metal used and its dimensions
(including its configuration), but also on the type of its enclosure and
holder. The latter not only affect the melting time, but, in addition, affect
the arc clearing time. The clearing time of the fuse, then, is the sum
of the melting time and the arc clearing time.

Fuse Coordination
The number, rating, and type of the interrupting devices shown
in Figure 4-3 depend on the system voltage, normal current, maximum
fault current, the sections and equipment connected to them, and other
local conditions. The devices are usually located at branch intersections
and at other key points. When two or more such devices are employed
in a circuit, they will be coordinated so that only the faulted portion will
be de-energized. In Figure 4-28 fuse D must clear before sectionalizer C,
and C must clear before recloser B. Likewise, fuse G must clear before
F, F before E, and both E and B before A. At the transformer locations,
fuse M must clear before D, and N before G. All of these devices must be
coordinated; i.e., their ratings should provide for carrying normal load
currents and for responding correctly to a fault.

Fault current will flow from the source to the fault through the
various devices in its path. The magnitude of this fault current will depend
on the impedance (resistance for dc circuits) between the source
and the point of fault, or roughly, on the distance between them. When
a fault is distant from the source, the impedance of this part of the circuit
is high and the fault current is low; when the fault is close to the source,
the fault current is high.

At the coordinating point farthest from the source, therefore, the
fuse will have the lowest rating consistent with the maximum normal
load at this point; at the other coordinating points along the path of the
current the fuses will have increased ratings as they are closer to the
source. These are indicated in Figure 4-15 and Table 4-3. The characteristics
of these fuses must also coordinate with those of other protective
devices in the same path and with those of the circuit breaker at the
source.


Repeater Fuses
Line fuses are sometimes installed in groups of two or three (per
phase), known as repeater fuses, having a time delay between each two
fuse units. When a fault occurs, the first fuse will blow and the second
fuse will be mechanically placed in the circuit by the opening of the first;
if the fault persists, the second fuse will blow; if there is a third fuse, the
process is repeated. If the fault is permanent, all of the fuses will blow
and the faulted part of the circuit will be de-energized. New fuses must
be installed to restore the line to normal.
Where capacitors are applied to feeders for power factor correction,
fuses chosen to protect the line from the bank (and vice versa) must also
coordinate with sectionalizing and other devices in the circuit back to the
source.


Transformer Fuses
Fuses on the primary side of distribution transformers serve to disconnect
the transformer from the circuit not only in the event of a fault
in the transformer or on the secondary, but also when the normal load
on the transformer becomes so high that failure is imminent. Fuses on
the secondary side protect the transformer from faults or overloads on
the secondary circuit it serves.

The characteristics of a primary fuse are a compromise between
protection from a fault and protection from overload, yet the fuse also
has to coordinate with other fuses on the line. One attempt at a solution
is the completely self-protected (CSP) transformer, in which the primary
fuse, with characteristics based only on protection against fault, is situated
within the transformer tank (and, to differentiate, is called a link)
while overload protection is accomplished by low-voltage circuit breakers
(instead of fuses) on the secondary side of the transformer that are
also situated within the tank. The circuit breakers, once open, however,
must be reclosed manually.

Fuses are provided on the line side of the protectors on low-voltage
secondary networks. These are backup protection in the event the protector
fails to open during back feed from the network into the primary
when it is faulted or deliberately grounded.
Secondary fuses, known as limiters, are also provided at the juncture
of secondary mains to isolate faulted sections of the secondary
mains and to prevent the spread of burning in conductors (usually in
cables) where sufficient fault current does not exist to burn them clear
in a small portion of the mains.

Automatic Line Sectionalizers
Automatic line sectionalizers are connected on the distribution
feeder in series with line and sectionalizing fuses; they are also in series
with and electrically farther from the source than reclosers or circuit
breakers with reclosing cycles. These devices are decreasing in usage,
but many exist on distribution systems.

When a fault occurs on the circuit beyond the sectionalizer, the
fault current initiates a fault-counting relay that is coordinated with the
characteristics of the fuses and other devices. Each time the circuit is deenergized
(from reclosers or circuit breakers), the relay moves toward
the trip position; just before the final operation that will lock out the
recloser or circuit breaker if the fault persists, the sectionalizer will trip
(while no fault current is flowing) and open the circuit at that point,
removing the fault and permitting the circuit breaker or recloser to close
and reset into its normal position; service is thus restored to the rest of
the circuit up to the location of the sectionalizer. If the fault is of a temporary
nature and is cleared before the reclosing devices complete their
operations, the sectionalizer will reset to its normal position after the
circuit is reenergized.

Sectionalizers are rated on continuous current-carrying capacity,
minimum tripping and counting current, and maximum momentary
fault current, as well as for maximum system voltage, load-break current,
and impulse voltage or basic insulation level (BIL).
More than one sectionalizer can be connected in series with a reclosing
device. The sectionalizer nearest the reclosing device can be set
to operate after (say) three operations while the more remote one is set
for (say) two such operations.
Sectionalizers are relatively low-cost devices; they are not required
to interrupt fault current although fault current flows through them.
They may be operated manually and are considered the same as loadbreak
switches.

Reclosers
Reclosers are essentially circuit breakers of lower capacity, both as
to normal current and interrupting duty. They are usually installed on
major branches of distribution feeders in series with other sectionalizing
devices; they perform the same function as repeater fuses connected in
the circuit or circuit breakers at the substation.

Circuit Breakers—Relays
Where the fault current is beyond the ability of a fuse or recloser to
interrupt it safely, or where repeated operation within a short period of
time makes it more economical, a circuit breaker is used. The ability of
circuit breakers has been touched upon earlier; their time-current characteristics,
however, are dependent on the protective relays associated with
them and must be coordinated with those of down-line reclosers, fuses,
and other protective devices.

Overcurrent Relays
Overcurrent relays close their contacts to actuate the circuit that
causes the circuit breaker to open or close when the current flowing in
them reaches a predetermined value.

Instantaneous
Without time delay deliberately added, the relay will close its
contacts “instantaneously,” i.e., in a relatively short time, in the nature
of 0.5 to perhaps 20 cycles. To prevent frequent operation of the breaker
from transient, nonpersistent conditions, undesirably high settings may
be applied to the relay.


Directional Relays
Directional relays are essentially overcurrent relays to which an
element similar to a wattmeter is added, both sets of contacts being in
series. The overcurrent element will operate to close its contacts regardless
of the direction of flow of power in the line; the wattmeter element
will tend to turn in one direction under normal flow of power and in
the reverse direction when power flows in the opposite direction. Hence,
both sets of contacts must be closed and power flowing in a given direction
before the relay will operate. Both elements may be combined into
one so that only a single set of contacts is required.


Differential Relays
Differential relays operate on the difference between the current entering
the line or equipment being protected and the current leaving it.
As long as the incoming current and the outgoing current are essentially
equal, the relay will not operate. A fault within the line or equipment,
however, will disturb this equilibrium, and the relay will operate to trip
the supply circuit breaker or breakers on both sides of the line or equipment
being protected. This type of relay is used to protect buses, transformers,
and regulators at the substation. Since the voltages at which
these operate may be high, current transformers installed on both sides
of the equipment, with proper ratios in the case of transformers, supply
the currents to the relay.


Surge or Lightning Arresters
The function of a surge or lightning arrester is to limit the voltage
stresses on the insulation of the equipment being protected by permitting
surges in voltage to drain to ground before damage occurs. The
surges in voltage generally are caused by lightning (either by direct
stroke or by induction from a nearby stroke) or by switching.

Arresters consist of two basic components: a spark gap and a nonlinear
resistance element (for a valve type) or an expulsion chamber (for
an expulsion type). When a surge occurs, the spark gap breaks down
or sparks over, and permits current to flow through the resistance (or
chamber) element to ground. Since the arrester at this point presents a
low-impedance path, a large current, referred to as 60-cycle follow current,
flows through the arrester. The nonlinear resistance, at the higher voltages,
will tend to restrict this current and eventually cause it to cease to flow;
here, the magnitude of the follow current is independent of the system
capacity.

The expulsion chamber will confine the arc, build up pressures
that eventually blow out the arc, and cause the follow current to cease to
flow; here, the follow current is a function of the system capacity and the
expulsion chamber must be suitably designed. After each such operation,
the arrester must be capable of repeating this operating cycle.

Insulation Coordination
It must be kept in mind that while the arrester is operating, the
surge voltage is also “attacking” the insulation of the line or equipment
it is protecting; the arrester, however, drains the high voltage to ground,
reducing its magnitude, before sufficient time has elapsed to damage the
insulation of the line or equipment.
Insulation characteristics, therefore, can be expressed as functions
of voltage and the time it is impressed. This is usually shown as a volttime
curve, known as the impulse level, and represents the voltage and
its duration the equipment can withstand.
The arrester also has a volt-time curve that indicates the voltage
and time at which the spark gap begins to break down and permit the
passage of the surge to ground.

The insulation characteristic of the line or equipment being protected
must be at a higher voltage level than the volt-time characteristic of the
arrester protecting it; indeed, a sufficient voltage differential must be provided
to ensure safe and positive protection. Figure 4-23 illustrates typical
curves and their relationship. While the impulse level of the line or equipment
must be high enough that the arrester provides adequate protection,
it should be as low as practical to hold down insulation costs.

Basic Insulation Level (BIL)
The coordination of insulation requires the establishment of a
minimum level above which are the components of a system and below
which are the protected devices associated with those components. A
joint committee of electrical engineers, utilities, and manufacturers adopted
basic insulation levels which define the impulse voltages capable
of being withstood by insulation of various insulation classes: “Basic
impulse insulation levels are reference levels expressed in impulse crest
voltages with a standard wave not longer than 1.5 by 40 microseconds.
Apparatus insulation as demonstrated by suitable tests shall be equal to
or greater than the basic insulation level.”

The standard 1.5- by 40-μs wave selected simulates lightning
surges, which are more prevalent than switching surges, and are more
readily reproduced in the laboratory.


Arrester Connection
Arresters should be placed as close to the equipment to be protected,
and the lengths of the connections to the line and to the ground
should be kept as short, as possible. That is because these connections
offer relatively high-impedance paths to voltage surges, so that large
currents flowing through them could cause a voltage drop in them
which, added to the surge voltage, could impose additional stress on
the insulation of the equipment being protected. Moreover, on longer
lines, such surges can be “reflected,” essentially doubling the value of
the surge voltage.

Short leads and minimum distance between the arrester and equipment
protected are desirable for all arrester applications. Further, if the
equipment being protected has a ground, that ground and the arrester
ground should be interconnected to relieve any potential stress that may
develop from the voltage drop across the ground impedance.

Arresters should be connected to the primary side of distribution
transformers and to capacitors, underground risers, and other
equipment; at certain points on long primary lines; and at reclosers in
substations. One arrester should be connected to each phase. For station
circuit breakers, transformers, outdoor regulators, and reclosers
situated on primary lines, arresters should preferably be connected to
both incoming and outgoing sides of such equipment. Voltage ratings
of arresters should take cognizance of whether the systems are delta or
wye, grounded or ungrounded, and of the voltage distortions resulting
from an accidental ground on one phase.

Read More - Protective Devices

Arti K3 di Bidang Teknik Sipil

 Dalam rangka memperingati bulan Keselamatan dan Kesehatan Kerja (K3), pada tanggal 20 Pebruari 2010 Menteri Pendidikan Nasional RI, Prof. Dr. Ir. H. Mohammad Nuh, DEA dan Menteri Tenaga Kerja dan Transmigrasi RI, Ds. H. A. Muhaimin Iskandar, M. Si., tampil bersama sebagai pembicara dalam seminar nasional bulan K3 (Keselamatan dan Kesehatan Kerja) di ITS, Surabaya. Seminar dengan tema "Peningkatan Sumber Daya Manusia Bidang Keselamatan dan Kesehatan Kerja (K3) melalui Institusi Pendidikan Tinggi untuk Mewujudkan Indonesia Berbudaya K3", diikuti oleh para mahasiswa dan dosen, serta utusan perusahaan.
 
Mendiknas tampil lebih dulu dengan membawakan topik "Peran Pendidikan Tinggi dalam Memutus Mata Rantai Kemiskinan dan Mendukung Pembudayaan Keselamatan dan Kesehatan Kerja." Selanjutnya Menakertrans membawakan topik yang tidak kalah menarik yaitu "Tantangan Global SDM Bidang Keselamatan dan Kesehatan Kerja dan Peran Pendidikan Tinggi dalam Menghadapinya." Dalam hal ini, Mendiknas sangat mendukung penuh program pembudayaan K3 yang dicanangkan oleh Menakertrans sehingga terdapat korelasi yang kuat antara keduanya.

Penerapan K3 sangat penting terhadap kesejahteraan pekerja, nilai investasi, kualitas, kuantitas produk, kelangsungan usaha perusahaan, serta daya saing sebuah negara.

            Sebelumnya pada tahun 2009 telah dilakukan kesepakatan antara Menteri Pekerjaan Umum dan Menakertrans tentang Pakta Komitmen K3 Departemen PU. Pada saat itu Menteri PU menilai bahwa Keselamatan adalah kebutuhan utama setiap individu dalam menjalankan aktifitas, termasuk dalam melakukan pekerjaan konstruksi. Oleh sebab itu ia menyatakan:”Keselamatan adalah Hakekat kehidupan”. Hasil kajianpun membuktikan bahwa pembangunan konstruksi merupakan salah satu bagian sektor pembangunan yang memiliki risiko tinggi dalam hal keselamatan kerja.

Atas dasar itu, Menteri PU mengajak semua pihak terkait untuk memberi perhatian yang sungguh-sungguh terhadap K3 khususnya dilingkup pekerjaan konstruksi. Sebagai bukti dukungannya, Menteri PU telah menerbitkan Permen PU No.09/PRT/M/2008 tentang Pedoman Sistem Manajemen Keselamtaan dan Kesehatan Kerja (SMK3) Konstruksi Bidang Pekerjaan Umum. 

              Menurutnya, Peraturan Menteri itu merupakan kebijakan pemerintah dalam rangka membudayakan K3 di sektor konstruksi Indonesia. Hal itu menunjukkan bahwa instansi yang dipimpinnya selaku pembina konstruksi memiliki tugas, tanggungjawab dan wewenang dalam mengupayakan secara maksimal penerapan K3 dalam penyelenggaraan bidang pekerjaan umum. Lebih lanjut Menteri PU meminta kepada segenap jajarannya untuk melaksanakan dan memahami 7 butir kebijakan yang tercantum dalam Pakta Komitmen K3 Departemen PU yang telah ditandatanganinya bersama mitra kerjanya tersebut. 7 butir kebijakan itu antara lain berbunyi:”memastikan SMK3 guna mengurangi, mengeliminasi dan menghindari resiko kecelakaan dan sakit akibat kerja.”  

              Sementara itu, pada kesempatan yang sama Menakertrans Erman Suparno juga menyerukan akan arti pentingnya K3 dalam dunia jasa konstruksi. Bahkan beliau mengajak kepada pihak-pihak yang kompeten dibidang konstruksi untuk terus menggalakkan dan selalu meningkatkan penerapan K3. ”Bicara pekerjaan kita adalah bagian dari pekerja itu sendiri. Jadi bukan dalam arti  yang sesungguhnya tapi bagian dari kerja,” ungkapnya.

              Lebih lanjut dinyatakan bahwa komitmen adalah kuncinya. Komitmen adalah implementasi dari komitmen itu sendiri agar pihak yang terkait di dalamnya bersama-sama meningkatkan K3 dalam budaya kerja. Dari sisi ekonomi K3 merupakan bagian dari proses pembangunan ekonomi kita. Penerapan budaya K3 dinilai mampu menurunkan angka kasus kejadian kecelakaan kerja dengan drastis setiap tahunnya. Misalnnyan, pada tahun 2008 tercatat 58 ribu kasus kecelakaan, sedangkan tahun-tahun sebelumnya kecelakaan kerja mencapai 120 ribu kasus.  Berdasarkan angka penurunan ini membuktikan bahwa penerapan K3 dalam proyek konstruksi dipandang sangat penting.

 Kebutuhan membangun hubungan industrial, bukan semata-mata dilihat dari besarnya upah pekerja saja, melainkan juga perhatian yang diberikan pemerintah terhadap keselamatan pekerjanya. Hal ini didasarkan kepada Pasal 4 Undang-undang nomor 13 Tahun 2003 yang antara lain menyebutkan:”pemerintah memberikan perlindungan kepada tenaga kerja dalam mewuju kesejahteraan tenaga kerja.”

             Dengan demikian penyedia jasa konstruksi perlu mengetahui dan memahami tugas dan kewajiban dalam penyelenggaraan K3 Konstruksi Bidang Pekerjaan Umum, sehingga dapat mencegah terjadinya kecelakaan kerja konstruksi dan penyakit akibat kerja konstruksi serta menciptakan lingkungan kerja yang aman dan nyaman, yang pada akhirnya akan meningkatkan produktivitas kerja. Para Pelaku Konstruksi, baik itu Pengguna Jasa maupun Penyedia Jasa harus benar-benar memahami akan pentingnya K3, karena kecelakaan kerja tidak hanya dapat menimpa para pekerja, akan tetapi dapat pula menimpa pihak-pihak lain yang tidak terlibat dalam pekerjaan tersebut. Penyedia Jasa Konstruksi harus menerapkan prinsip-prinsip K3 Konstruksi dengan benar agar kecelakaan kerja dan penyakit akibat kerja konstruksi dapat dihindari atau setidaknya diminimalisir sekecil mungkin.

Read More - Arti K3 di Bidang Teknik Sipil

Tujuan K3

Secara umum, kecelakaan selalu diartikan sebagai kejadian yang tidak dapat diduga. Kecelakaan kerja dapat terjadi karena kondisi yang tidak membawa keselamatan kerja, atau perbuatan yang tidak selamat. Kecelakaan kerja dapat didefinisikan sebagai setiap perbuatan atau kondisi tidak selamat yang dapat mengakibatkan kecelakaan.

Berdasarkan definisi kecelakaan kerja maka lahirlah keselamatan dan kesehatan kerja yang mengatakan bahwa cara menanggulangi kecelakaan kerja adalah dengan meniadakan unsur penyebab kecelakaan dan atau mengadakan pengawasan yang ketat. (Silalahi, 1995)

Keselamatan dan kesehatan kerja pada dasarnya mencari dan mengungkapkan kelemahan yang memungkinkan terjadinya kecelakaan. Fungsi ini dapat dilakukan dengan dua cara, yaitu mengungkapkan sebab-akibat suatu kecelakaan dan meneliti apakah pengendalian secara cermat dilakukan atau tidak.

Menurut Mangkunegara (2002, p.165) bahwa tujuan dari keselamatan dan kesehatan kerja adalah sebagai berikut:
a. Agar setiap pegawai mendapat jaminan keselamatan dan kesehatan kerja baik secara fisik, sosial, dan psikologis.
b. Agar setiap perlengkapan dan peralatan kerja digunakan sebaik-baiknya selektif mungkin.
c. Agar semua hasil produksi dipelihara keamanannya.
d. Agar adanya jaminan atas pemeliharaan dan peningkatan kesehatan gizi pegawai.
e. Agar meningkatkan kegairahan, keserasian kerja, dan partisipasi kerja.
f. Agar terhindar dari gangguan kesehatan yang disebabkan oleh lingkungan atau kondisi kerja.
g. Agar setiap pegawai merasa aman dan terlindungi dalam bekerja

Read More - Tujuan K3

PENGANTAR PENDIDIKAN KESELAMATAN DAN KESEHATAN KERJA (K3)

Latar Belakang

          Cuplikan informasi dari artikel yang dimuat media Solo Pos tertanggal 12 Januari 2010 sebagaimana tertulis dibawah ini memberikan gambaran terkini kondisi penerapan K3 di Indonesia.

Jakarta–Pemerintah mencatat sepanjang 2009 telah terjadi sebanyak 54.398 kasus kecelakaan kerja di Indonesia. Angka tersebut mengalami tren menurun sejak 2007 yang sempat mencapai 83.714 kasus dan melorot pada 2008 yang hanya 58.600 kasus. Menteri Tenaga Kerja dan Transmigrasi Muhaimin Iskandar mengaku, kasus kecelakaan kerja di Indonesia masih relatif tinggi bila dibandingkan dengan negara lain. “Oleh karena itu saya himbau kepada seluruh Gubernur, Bupati, maupun Walikota melakukan upaya konkrit pelaksanaan K3 (Keselamatan dan Kesehatan Kerja) untuk mengurangi angka kecelakaan kerja,” kata Muhaimin di sela-sela Upacara Hari Keselamatan dan Kesehatan Kerja Nasional di kantor Gatot Subroto, Jakarta, Selasa (12/1). Dari lebih dari 50 ribu kasus kecelakaan kerja tahun lalu, sebanyak 20.086 kasus tergolong pelanggaran K3 dan sebanyak 107 kasus sedang masuk proses penyidikan (Berita Acara Pemeriksaan-BAP). Untuk mengurangi angka kecelakaan kerja, menurut Muhaimin, juga akan dikaji kembali formulasi untuk membangun tripartit di bidang pengawasan ketenagakerjaan. Hal ini untuk mengantisipasi kurangnya jumlah pengawas pekerjaan, dan kurangnya partisipasi pihak-pihak yang menjaga dan mengawasi sesuai standar dalam UU No. 1 tahun 1970 dan UU No. 13 tahun 2003. “Dengan tripartit pengawasan akan memudahkan pengawasan dan memudahkan pelaporan, penindakan, serta pembinaan kepada pelanggar dari sistem dan UU Ketenagakerjaan,” ujarnya. Menurut data Depnakertrans, sepanjang tahun 2009, terdapar 18.244 unit Satgas K3, 440 Perusahaan Jasa Keselamatan dan Kesehatan Kerja (PJK3), 5 perusahaan Badan Audit K3, 1.120 perusahaan yang menerapkan Sistem Manajemen Keselamatan dan Kesehatan Kerja (SMK3), dan sebanyak 2.524 perusahaan yang nihil kecelakaan kerjanya. Dalam upacara peringatan 100 tahun K3 yang diperingati pada bulan ini, Muhaimin menyerahkan bantuan 20 mobil tanggap darurat K3 masing-masing untuk, Provinsi Sumatra Utara, Riau, Sumatra Selatan, Bengkulu, Lampung, Banten, Jawa Barat, DKI Jakarta, Jawa Tengah, DIY, Jawa Timur, Bali, Kalimantan Selatan, kalimantan Timur, Sulawesi Selatan, Kabupaten Bekasi, Kabupaten Madiun, Kabupaten Sidoarjo, Kota Balikpapan, dan Ditjen Binwasnaker.//

Keselamatan dan kesehatan kerja difilosofikan sebagai suatu pemikiran dan upaya untuk menjamin keutuhan dan kesempurnaan baik jasmani maupun rohani tenaga kerja pada khususnya dan manusia pada umumnya, hasil karya dan budayanya menuju masyarakat makmur dan sejahtera.

Sedangkan pengertian secara keilmuan adalah suatu ilmu pengetahuan dan penerapannya dalam usaha mencegah kemungkinan terjadinya kecelakaan dan penyakit akibat kerja. (Alfarisi,2007)
Keselamatan dan kesehatan kerja (K3) tidak dapat dipisahkan dengan proses produksi baik jasa maupun industri. Perkembangan pembangunan setelah Indonesia merdeka menimbulkan konsekwensi meningkatkan intensitas kerja yang mengakibatkan pula meningkatnya resiko kecelakaan di lingkungan kerja.

Keselamatan dan kesehatan kerja merupakan salah satu upaya perlindungan kerja yang ditujukan kepada semua potensi yang dapat menimbulkan bahaya, agar tenaga kerja dan orang lain yang ada di tempat kerja selalu dalam keadaan selamat dan sehat serta semua sumber produksi dapat digunakan secara aman dan efisien.

Keselamatan kerja berkaitan dengan resiko yang dihadapi tenaga kerja ditempat kerja yang disebabkan oleh kecelakaan yang terjadi di dalam tempat kerja tersebut. Resiko itu mencakup semua jenis resiko termasuk yang disebabkan oleh bahan kimia.

Kesehatan kerja berkaitan dengan kemungkinan ancaman terhadap kesehatan tenaga kerja di tempat kerja selama waktu kerja yang normal.

Kesehatan kerja melibatkan tidak hanya tenaga kerja, tetapi mencakup aspek yang berkaitan dengan kondisi di tempat kerja seperti kebersihan, suhu, sirkulasi udara/ventilasi, penerangan, kesehatan pribadi, serta pemaparan dari bahan kimia.

Kecelakaan kerja meliputi semua kecelakaan di industri atau tempat kerja. Potensi-potensi yang dapat menimbulkan bahaya dapat berasal dari:

1. Alat-alat kerja, bahan-bahan, energi, mesin-mesin.
2. Lingkungan kerja.
3. Sifat pekerjaan.
4. Cara  kerja.
5. Proses produksi.

Keberadaan alat-alat kerja, bahan-bahan, energi dan mesin-mesin yang semakin hari bertambah kompleks serta beraneka ragam, cara kerja yang kurang baik karena kurang pengalaman dan keterampilan, dapat memperberat dan memperbesar resiko kerja berupa kecelakaan dan berbagai penyakit akibat kerja.

Read More - PENGANTAR PENDIDIKAN KESELAMATAN DAN KESEHATAN KERJA (K3)

Korelasi K3 dan Produktivitas Kerja

K3 dapat melakukan pencegahan dan pemberantasan penyakit akibat kerja, misalnya kebisingan, pencahayaan (sinar), getaran, kelembaban udara, dan lain-lain yang dapat menyebabkan kerusakan pada alat pendengaran, gangguan pernapasan, kerusakan paru-paru, kebutaan, kerusakan jaringan tubuh akibat sinar ultraviolet, kanker kulit, kemandulan, dan lain-lain. Norma kerja berkaitan dengan manajemen perusahaan.

K3 dalam konteks ini berkaitan dengan masalah pengaturan jam kerja, shift, kerja wanita, tenaga kerja kaum muda, pengaturan jam lembur, analisis dan pengelolaan lingkungan hidup, dan lain-lain. Hal-hal tersebut mempunyai korelasi yang erat terhadap peristiwa kecelakaan kerja.

Eksistensi K3 sebenarnya muncul bersamaan dengan revolusi industri di Eropa, terutama Inggris, Jerman dan Prancis serta revolusi industri di Amerika Serikat. Era ini ditandai adanya pergeseran besar-besaran dalam penggunaan mesin-mesin produksi menggantikan tenaga kerja manusia. Pekerja hanya berperan sebagai operator.

Penggunaan mesin-mesin menghasilkan barang-barang dalam jumlah berlipat ganda dibandingkan dengan yang dikerjakan pekerja sebelumnya. Revolusi IndustriNamun, dampak penggunaan mesin-mesin adalah pengangguran serta risiko kecelakaan dalam lingkungan kerja.

Ini dapat menyebabkan cacat fisik dan kematian bagi pekerja. Juga dapat menimbulkan kerugian material yang besar bagi perusahaan. Revolusi industri juga ditandai oleh semakin banyak ditemukan senyawa-senyawa kimia yang dapat membahayakan keselamatan dan kesehatan fisik dan jiwa pekerja (occupational accident) serta masyarakat dan lingkungan hidup.

Pada awal revolusi industri, K3 belum menjadi bagian integral dalam perusahaan. Pada era in kecelakaan kerja hanya dianggap sebagai kecelakaan atau resiko kerja (personal risk), bukan tanggung jawab perusahaan.

Pandangan ini diperkuat dengan konsep common law defence (CLD) yang terdiri atas contributing negligence (kontribusi kelalaian), fellow servant rule (ketentuan kepegawaian), dan risk assumption (asumsi resiko) (Tono, Muhammad: 2002). Kemudian konsep ini berkembang menjadi employers liability yaitu K3 menjadi tanggung jawab pengusaha, buruh/pekerja, dan masyarakat umum yang berada di luar lingkungan kerja.Dalam konteks bangsa Indonesia, kesadaran K3 sebenarnya sudah ada sejak pemerintahan kolonial Belanda.

Misalnya, pada 1908 parlemen Belanda mendesak Pemerintah Belanda memberlakukan K3 di Hindia Belanda yang ditandai dengan penerbitan Veiligheids Reglement, Staatsblad No. 406 Tahun 1910. Selanjutnya, pemerintah kolonial Belanda menerbitkan beberapa produk hukum yang memberikan perlindungan bagi keselamatan dan kesehatan kerja yang diatur secara terpisah berdasarkan masing-masing sektor ekonomi.

Beberapa di antaranya yang menyangkut sektor perhubungan yang mengatur lalu lintas perketaapian seperti tertuang dalam Algemene Regelen Betreffende de Aanleg en de Exploitate van Spoor en Tramwegen Bestmend voor Algemene Verkeer in Indonesia (Peraturan umum tentang pendirian dan perusahaan Kereta Api dan Trem untuk lalu lintas umum Indonesia) dan Staatblad 1926 No. 334, Schepelingen Ongevallen Regeling 1940 (Ordonansi Kecelakaan Pelaut), Staatsblad 1930 No. 225, Veiligheids Reglement (Peraturan Keamanan Kerja di Pabrik dan Tempat Kerja), dan sebagainya.

Kepedulian Tinggi Pada awal zaman kemerdekaan, aspek K3 belum menjadi isu strategis dan menjadi bagian dari masalah kemanusiaan dan keadilan. Hal ini dapat dipahami karena Pemerintahan Indonesia masih dalam masa transisi penataan kehidupan politik dan keamanan nasional. Sementara itu, pergerakan roda ekonomi nasional baru mulai dirintis oleh pemerintah dan swasta nasional.

K3 baru menjadi perhatian utama pada tahun 70-an searah dengan semakin ramainya investasi modal dan pengadopsian teknologi industri nasional (manufaktur). Perkembangan tersebut mendorong pemerintah melakukan regulasi dalam bidang ketenagakerjaan, termasuk pengaturan masalah K3.

Hal ini tertuang dalam UU No. 1 Tahun 1070 tentang Keselamatan Kerja, sedangkan peraturan perundang-undangan ketenagakerjaan sebelumnya seperti UU Nomor 12 Tahun 1948 tentang Kerja, UU No. 14 Tahun 1969 tentang Ketentuan-ketentuan Pokok Mengenai Tenaga Kerja tidak menyatakan secara eksplisit konsep K3 yang dikelompokkan sebagai norma kerja.Setiap tempat kerja atau perusahaan harus melaksanakan program K3.

Tempat kerja dimaksud berdimensi sangat luas mencakup segala tempat kerja, baik di darat, di dalam tanah, di permukaan tanah, dalam air, di udara maupun di ruang angkasa.

Pengaturan hukum K3 dalam konteks di atas adalah sesuai dengan sektor/bidang usaha. Misalnya, UU No. 13 Tahun 1992 tentang Perkerataapian, UU No. 14 Tahun 1992 tentang Lalu Lintas dan Angkutan Jalan (LLAJ), UU No. 15 Tahun 1992 tentang Penerbangan beserta peraturan-peraturan pelaksanaan lainnya.

Selain sekor perhubungan di atas, regulasi yang berkaitan dengan K3 juga dijumpai dalam sektor-sektor lain seperti pertambangan, konstruksi, pertanian, industri manufaktur (pabrik), perikanan, dan lain-lain.

Persaingan global tidak hanya sebatas kualitas barang tetapi juga mencakup kualitas pelayanan dan jasa. Banyak perusahaan multinasional hanya mau berinvestasi di suatu negara jika negara bersangkutan memiliki kepedulian yang tinggi terhadap lingkungan hidup. Juga kepekaan terhadap kaum pekerja dan masyarakat miskin. Karena itu bukan mustahil jika ada perusahaan yang peduli terhadap K3, menempatkan ini pada urutan pertama sebagai syarat investasi.

Read More - Korelasi K3 dan Produktivitas Kerja

Pengertian dan Ruang Lingkup Kesehatan dan keselamatan kerja (K3)

Keselamatan dan kesehatan kerja (K3) merupakan instrumen yang memproteksi pekerja, perusahaan, lingkungan hidup, dan ma-syarakat sekitar dari bahaya akibat kecelakaan kerja. Perlindungan tersebut merupakan hak asasi yang wajib dipenuhi oleh perusahaan. K3 bertujuan mencegah, mengurangi, bahkan menihilkan risiko kecelakaan kerja (zero accident).

Penerapan konsep ini tidak boleh dianggap sebagai upaya pencegahan kecelakaan kerja dan penyakit akibat kerja yang menghabiskan banyak biaya (cost) perusahaan, melainkan harus dianggap sebagai bentuk investasi jangka panjang yang memberi keuntungan yang berlimpah pada masa yang akan datang.

Menurut Sumakmur (1988) kesehatan kerja adalah spesialisasi dalam ilmu kesehatan/kedokteran beserta prakteknya yang bertujuan, agar pekerja/masyarakat pekerja beserta memperoleh derajat kesehatan yang setinggi-tingginya, baik fisik, atau mental, maupun sosial, dengan usaha-usaha preventif dan kuratif, terhadap penyakit-penyakit/gangguan –gangguan kesehatan yang diakibatkan faktor-faktor pekerjaan dan lingkungan kerja, serta terhadap penyakit-penyakit umum.

Keselamatan kerja sama dengan Hygiene Perusahaan.

Kesehatan kerja memiliki sifat sebagai berikut :

a. Sasarannya adalah manusia

b. Bersifat medis.

Pengertian sehat senantiasa digambarkan sebagai suatu kondisi fisik, mental dan sosial seseorang yang tidak saja bebas dari penyakit atau gangguan kesehatan melainkan juga menunjukan kemampuan untuk berinteraksi dengan lingkungan dan pekerjaannya.

Paradigma baru dalam aspek kesehatan mengupayakan agar yang sehat tetap sehat dan bukan sekedar mengobati, merawat atau menyembuhkan gangguan kesehatan atau penyakit. Oleh karenanya, perhatian utama dibidang kesehatan lebih ditujukan ke arah pencegahan terhadap kemungkinan timbulnya penyakit serta pemeliharaan kesehatan seoptimal mungkin.

Status kesehatan seseorang, menurut blum (1981) ditentukan oleh empat faktor yakni :
1. Lingkungan, berupa lingkungan fisik (alami, buatan) kimia (organik / anorganik, logam berat, debu), biologik (virus, bakteri, microorganisme) dan sosial budaya (ekonomi, pendidikan, pekerjaan).
2. Perilaku yang meliputi sikap, kebiasaan, tingkah laku.
3. pelayanan kesehatan: promotif, perawatan, pengobatan, pencegahan kecacatan, rehabilitasi, dan
4. genetik, yang merupakan faktor bawaan setiap manusia.

Demikian pula status kesehatan pekerja sangat mempengaruhi produktivitas kerjanya. Pekerja yang sehat memungkinkan tercapainya hasil kerja yang lebih baik bila dibandingkan dengan pekerja yang terganggu kesehatannya”.

Menurut Suma’mur (1976) Kesehatan kerja merupakan spesialisasi ilmu kesehatan/kedokteran beserta prakteknya yang bertujuan agar pekerja/ masyarakat pekerja memperoleh derajat kesehatan setinggi-tingginya baik fisik, mental maupun sosial dengan usaha preventif atau kuratif terhadap penyakit/ gangguan kesehatan yang diakibatkan oleh faktor pekerjaan dan lingkungan kerja serta terhadap penyakit umum. Konsep kesehatan kerja dewasa ini semakin banyak berubah, bukan sekedar “kesehatan pada sektor industri” saja melainkan juga mengarah kepada upaya kesehatan untuk semua orang dalam melakukan pekerjaannya.

Keselamatan kerja adalah keselamatan yang bertalian dengan mesin, pesawat, alat kerja, bahan, dan proses pengolahannya, landasan tempat kerja dan lingkungannya serta cara-cara melakukan pekerjaan (Sumakmur, 1993).

Keselamatan kerja memiliki sifat sebagai berikut :

a. Sasarannya adalah lingkungan kerja

b. Bersifat teknik.

Pengistilahan Keselamatan dan Kesehatan kerja (atau sebaliknya) bermacam macam ; ada yang menyebutnya Higiene Perusahaan dan Kesehatan Kerja (Hyperkes) dan ada yang hanya disingkat K3, dan dalam istilah asing dikenal Occupational Safety and Health.

Keselamatan kerja atau Occupational Safety, dalam istilah sehari hari sering disebut dengan safety saja, secara filosofi diartikan sebagai suatu pemikiran dan upaya untuk menjamin keutuhan dan kesempurnaan baik jasmaniah maupun rohaniah tenaga kerja pada khususnya dan manusia pada umumnya serta hasil budaya dan karyanya.

Dari segi keilmuan diartikan sebagai suatu pengetahuan dan penerapannya dalam usaha mencegah kemungkinan terjadinya kecelakaan dan penyakit akibat kerja.
Pengertian Kecelakaan Kerja (accident) adalah suatu kejadian atau peristiwa yang tidak diinginkan yang merugikan terhadap manusia, merusak harta benda atau kerugian terhadap proses.

Dewasa ini pembangunan nasional tergantung banyak kepada kualitas, kompetensi dan profesionalisme sumber daya manusia termasuk praktisi keselamatan dan kesehatan kerja (K3). Dari segi dunia usaha diperlukan produktivitas dan daya saing yang baik agar dapat berkiprah dalam bisnis internasional maupun domestik. Salah satu faktor yang harus dibina sebaik-baiknya adalah implementasi K3 dalam berbagai aktivitas masyarakat khususnya dalam dunia kerja.

Pengertian Hampir Celaka, yang dalam istilah safety disebut dengan insiden (incident), ada juga yang menyebutkan dengan istilah “near-miss” atau “near-accident”, adalah suatu kejadian atau peristiwa yang tidak diinginkan dimana dengan keadaan yang sedikit berbeda akan mengakibatkan bahaya terhadap manusia, merusak harta benda atau kerugian terhadap proses kerja.

Bagaimana K3 dalam perspektif hukum? Ada tiga aspek utama hukum K3 yaitu norma keselamatan, kesehatan kerja, dan kerja nyata. Norma keselamatan kerja merupakan sarana atau alat untuk mencegah terjadinya kecelakaan kerja yang tidak diduga yang disebabkan oleh kelalaian kerja serta lingkungan kerja yang tidak kondusif.

Konsep ini diharapkan mampu menihilkan kecelakaan kerja sehingga mencegah terjadinya cacat atau kematian terhadap pekerja, kemudian mencegah terjadinya kerusakan tempat dan peralatan kerja. Konsep ini juga mencegah pencemaran lingkungan hidup dan masyarakat sekitar tempat kerja.Norma kesehatan kerja diharapkan menjadi instrumen yang mampu menciptakan dan memelihara derajat kesehatan kerja setinggi-tingginya. 

Ruang Lingkup K3

Ruang lingkup hyperkes dapat dijelaskan sebagai berikut (Rachman, 1990) :

a. Kesehatan dan keselamatan kerja diterapkan di semua tempat kerja yang di dalamnya melibatkan aspek manusia sebagai tenaga kerja, bahaya akibat kerja dan usaha yang dikerjakan.

b. Aspek perlindungan dalam hyperkes meliputi :

1) Tenaga kerja dari semua jenis dan jenjang keahlian

2) Peralatan dan bahan yang dipergunakan

3) Faktor-faktor lingkungan fisik, biologi, kimiawi, maupun sosial.

4) Proses produksi

5) Karakteristik dan sifat pekerjaan

6) Teknologi dan metodologi kerja

c. Penerapan Hyperkes dilaksanakan secara holistik sejak perencanaan hingga perolehan hasil dari kegiatan industri barang maupun jasa.

d. Semua pihak yang terlibat dalam proses industri/perusahaan ikut bertanggung jawab atas keberhasilan usaha hyperkes.

Read More - Pengertian dan Ruang Lingkup Kesehatan dan keselamatan kerja (K3)