Disabling a powerful electrical current-carrying parts, transformers or power lines fragment does not guarantee complete protection of people working on separate elements of the electrical systems of the lesions.On disconnected from the power supply section may be an unintended induced high voltage.To eliminate human exposure to unforeseen factors applied additional means of protection - Grounding portable, does not allow him to appear on the zone setting voltage hazardous to human values.
function portable earthing system consists in reducing to zero values or a random direction suddenly arisen because of someone else's error voltage.In fact, this remedy is a short to ground, or shorted area.In addition afte
of portable ground ↑
portable earthing system consists of 3 main parts, is:
- conductive component;
- contact portion;
- insulating element or several insulating elements.
on design features, portable security systems are divided into the rodless, rod and rod with units of metal.
rodless design includes:
- as part of a flexible conductive wire;
- contact portion, consisting of clamps, clamps with binding phase;
- insulating portion formed of a flexible tether to manage and maintain.
The composition Rod grounding portable device includes:
- conductive component is made of a flexible wire;
- contact phase clamps, clamps, ferrules;
- insulating rod made of a dielectric material.
of the portable device ground classified as a metal rod functioning systems are:
- conductive bar with the links of a metal having an electrical connection with a flexible wire;
- clamp terminal, connected to the clamp with a metal element;
- insulating dielectric rod is connected with the conductive component of the system, as well as with files.
These systems are available in three collective protection and single-phase.The three-phase portable devices with a single ground conductor is carried shorting and ground three phases.Single-phase devices are used to protect personnel working on powerful electrical installations with voltages exceeding operational 110 sq.This is justified by too great a distance between the phases, which is why the protection system can be very long and heavy.
systems for portable ground are used to protect people performing repair and installation workoverhead lines (VL) electric current transmission and distribution electrical installations (EDM).
systems for overhead lines portable earthing ↑
order to ensure safety during maintenance and upgrade work on overhead power lines applied in basically two types of single and three-phase portable earthing.
- devices equipped with solid insulating rod.They are set at work with lifts, towers, and when used to lift the manhole to the workplace and claws.
- grounding-carrying component with a rod consisting of conductive metal links.They are used when repairs of high voltage transmission lines are underway with traverses.They release them in a single-phase embodiment, since the length of the bar together with the metal parts differs too much weight.Single-phase devices provide a minimum load on the hands of the worker.
Protection for work on distribution installations ↑
induced lesions in from neighboring circuits or erroneously applies a voltage to the device to help eliminate distribution of portable earthing differ on the specifics of the installation in the switchgear.Installation of phase clamps can be made on cylindrical or spherical tips on bus bars, or at the location of the fuses.Structurally, all the devices are identical, the installation location to conduct regulated activities and the specific features of the service installation.
list of requirements for protective systems ↑
Safe to use, no inconvenience in installation, creating an impenetrable barrier to the risks portable equipment meets the following requirements:
- impeccable dynamic strength.Clamps should not break the effort linemen.
- Thermal stability to the called ground fault current.Elements of the device must not be burnt, melted, overheated from exposure to extremely high temperatures, otherwise burnt and ends there oplavivshihsya high voltage.
compounds in portable earthing conductors do welding or opressovaniem.If the wires are connected by means of bolts, fastening duplicated for strength brazing.Grounding with soldering without additional fixing elements are not allowed to use because the solder will melt.For the same reason, implying overheating short-circuit, portable earthing copper wires are not insulated.
Requirements for the imposition ground ↑
For technical regulations installing portable grounding is made on elements of all phases is fully disconnected from the power supply section.Disabling is done at all points in the connection, from which would flow stress also taking into account the reverse transformation.
each side of the grounding superimposed one that is sufficient to ensure electrical safety.Perhaps the separation of land from the live parts by means of disconnectors, circuit-breakers, can be separated by the removal of the fuse.
between the place of application of temporary ground must be a visible gap separating the device from the live parts with unexpunged voltage.The distance between the current-carrying components, which remained under stress, and the site should work to ensure the safety.
portable earthing installation in closed distribution systems is carried out on live parts in areas designated for the location of this particular means of security.They were purified from the paint and the outline represent black stripes.
Notice.Peeled paint space intended for the connection of portable systems to the protective earth wiring must be adapted to clamp fixing device or fitted with clamps.
If the electrical design for compelling reasons can not be imposed portable grounding necessary to further important measures to enhance the safety criteria.Prevent accidental or erroneous supply voltage, you can use the fence upper knife contacts or rigid insulation pads, rubber caps, you can use the drive locking device to lock isolator.
Installing portable devices ground ↑
Before applying the ground, carried out by installing insulating rods, make sure there is no voltage.According to the standards involved in the installation and dismantling of temporary ground by two men.Before checking the presence or absence of voltage grounding should be connected to terminal "Earth."
attention.In the hands of artists who are setting the bar should be insulating gloves.
important.It is forbidden to use conductors that are not designed to perform the ground.It is impossible to connect the wires by twisting.
- Connects grounding wire and grounding wire.
- voltage indicators checked his absence from the current-carrying elements.
- on live parts from all feed into the process, but disabled during repairs sides alternately using rods superimposed clips.
- mount is also produced by means of the bar.
Notice.When using a rod can not be performed fixing clamps can be mounted manually, but only the dielectric gloves (only when the work on installations with pressure to 110).Dielectric gloves are necessary for the implementation of virtually all activities from the overlay to the removal of the grounding of the portable device.
Installation portable remedies perform, standing on the floor of the shop or on the ground, sitting on the stairs, preferably made of wood or other dielectric.Climb the installation or design to verify the absence of voltage is strictly prohibited.
important.Voltage is not imposed on the conductors only when the ground connection.You can not immediately after the voltage prior to application of the ground and after the dismantling of the ground to touch the electrical components without any special protective equipment.
How to remove portable grounding ↑
To remove the grounding system the list of works in the reverse order.Any work carried out only in the gloves of the dielectric material.First, the device is removed from the live parts, then produce disconnection from the grounding devices.
All work related to the repair and modernization of electrical installations are dangerous.Failure to comply often turns tragic consequences.Ignoring means of collective electrical, should not expose themselves to unnecessary risks.