Installations of electric welding (cutting, surfacing) by melting

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Encyclopedia of radio electronics and electrical engineering / Electrician

Section 7. Electrical equipment of special installations

Electrical installations. Installations of electric welding (cutting, surfacing) by melting

Free technical library

Encyclopedia of radio electronics and electrical engineering / Rules for the installation of electrical installations (PUE)

Comments on the article

7.6.45. The passages between single-station sources of welding current - converters (static and motor-generator) of fusion welding (cutting, surfacing) installations - must be at least 0,8 m wide, between multi-station ones - at least 1,5 m, the distance from single- and multi-station welding current sources must be at least 0,5 m from the wall.

The passages between groups of welding transformers must be at least 1 m wide. The distance between welding transformers located next to each other in the same group must be at least 0,1 m.

The welding current regulator (if it is made in a separate shell) should be installed next to the welding transformer or above it. Installation of a welding transformer above the current regulator is not allowed.

7.6.46. The passages on each side of the rack for performing manual welding work on large parts or structures must be at least 1 m wide. Tables for small welding work can be adjacent on one side directly to the wall of the cabin; on other sides there must be passages at least 1 m wide. In addition, in the welding workshop (on site) passages must be provided, the width of which is set depending on the number of workers, but not less than 1 m.

7.6.47. The passages on each side of the automatic submerged arc welding installation of large products, as well as gas shielded arc welding, plasma, electron beam and laser welding installations must be at least 1,5 m wide.

7.6.48. To supply current from the welding current source to the electrode holder of a manual arc welding (cutting, surfacing) installation or to the direct-action plasma arc torch of a plasma cutting (welding) installation, a flexible wire with rubber insulation and a rubber sheath must be used. The use of wires with insulation or sheathing made of flame retardant materials is not permitted.

7.6.49. Electrical wiring of installations and devices intended for arc welding of critical structures: ship sections, load-bearing structures of buildings, bridges, aircraft, rolling stock of railways and other vehicles, vessels, boilers and pipelines for pressures of more than 5 MPa, pipelines for toxic substances and etc., must be made with wires with copper conductors.

7.6.50. Flexible and rigid wires, as well as, where possible, steel or aluminum buses of any profile of sufficient cross-section, welding plates, racks and welded structure (see also 7.6.48 and 7.6.51).

In electric welding installations with portable and mobile welding transformers, the return wire must be insulated in the same way as the direct wire connected to the electrode holder.

Elements used as a return wire must be securely connected by welding or using bolts, clamps or clamps.

7.6.51. In installations for automatic arc welding, if necessary (for example, when welding circular seams), it is possible to connect the return wire to the product being welded using a sliding contact of an appropriate design.

7.6.52. The use of metal building structures of buildings, pipelines and process equipment, as well as grounding network conductors, is not allowed as a return wire.

7.6.53. Electrode holders for manual arc welding and cutting with metal and carbon electrodes must meet the requirements of current standards.

7.6.54. The open circuit voltage of the welding current source of arc welding installations at the rated voltage of the supply electrical network should not exceed 100 V for direct current sources (average value) and for alternating current sources (rms value):

80 V - for automatic arc welding installations with a rated welding current of 630 A;
120 V - for automatic arc welding installations with a rated welding current of 1600 A;
140 V - for automatic arc welding installations with a rated welding current of 2000 A.

In the welding current circuit, short-term voltage peaks are allowed when the arc breaks, lasting no more than 0,5 s.

7.6.55. To excite the arc in arc welding (cutting) installations without first closing the welding circuit between the electrode and the workpiece and to increase the stability of the arc, the use of high-frequency converters (oscillators) is allowed.

To increase the stability of an alternating current arc, it is allowed to use pulse generators in arc welding (cutting) installations, which sharply increase the voltage between the electrode and the welded product at the moment of re-excitation of the arc. The pulse generator should not increase the open circuit voltage of the welding transformer by more than 1 V (rms value).

7.6.56. The rated voltage of electric motors and electrical devices located on the portable parts of electric welding machines and semi-automatic machines should be no higher than 50 V AC or 110 V DC. Electric motors and electrical devices of alternating current must be connected to the mains through a step-down transformer with a grounded secondary winding or through an isolating transformer that is part of the welding device. The housings of electric motors and electrical devices may not be grounded. Electric motors and electrical devices located on parts of stationary and mobile electric welding machines mounted on stationary installations may be powered from a 220 and 380 V AC network or from a 220 and 440 V DC network with mandatory grounding of their cases, which must be electrically insulated from parts galvanically connected to the welding circuit.

7.6.57. The open-circuit voltage of the welding current sources of plasma processing installations at the rated network voltage should not be higher than:

500 V - for automatic cutting, spraying and plasma-mechanical processing installations;
300 V - for semi-automatic cutting or spraying installations;
180 V - for manual cutting, welding or surfacing installations.

7.6.58. Installations for automatic plasma cutting must have a lock that prevents bridging of the closing contacts in the power circuit of the switching device coil without an electric arc.

7.6.59. The mechanized plasma cutting process must be controlled remotely. The no-load voltage to the arc head before the appearance of the “standby” arc must be supplied by turning on the switching device when pressing the “Start” button, which does not have a self-locking device. The "Start" button should be locked automatically after the "pilot" arc is excited.

7.6.60. Welding current power supplies for electron guns of electron beam welding installations must have a spark gap installed between the output of the positive pole of the rectifier and its grounded body. In addition, to prevent breakdowns of the insulation of the low voltage circuits of the installation and the insulation in the supply electrical network to which the installation is connected, caused by induced charges in the primary windings of step-up transformers, capacitors or other protective measures must be connected between the terminals of the primary winding and the ground.

7.6.61. Electron beam welding installations must have protection from hard and soft X-rays, ensuring their complete radiation safety, in which the level of radiation in the workplace should not be higher than that allowed by current regulations for persons not working with sources of ionizing radiation.

See other articles Section Rules for the installation of electrical installations (PUE).

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

The world's tallest astronomical observatory opened 04.05.2024

Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>

Controlling objects using air currents 04.05.2024

The development of robotics continues to open up new prospects for us in the field of automation and control of various objects. Recently, Finnish scientists presented an innovative approach to controlling humanoid robots using air currents. This method promises to revolutionize the way objects are manipulated and open new horizons in the field of robotics. The idea of controlling objects using air currents is not new, but until recently, implementing such concepts remained a challenge. Finnish researchers have developed an innovative method that allows robots to manipulate objects using special air jets as "air fingers". The air flow control algorithm, developed by a team of specialists, is based on a thorough study of the movement of objects in the air flow. The air jet control system, carried out using special motors, allows you to direct objects without resorting to physical ... >>

Purebred dogs get sick no more often than purebred dogs 03.05.2024

Caring for the health of our pets is an important aspect of the life of every dog owner. However, there is a common assumption that purebred dogs are more susceptible to diseases compared to mixed dogs. New research led by researchers at the Texas School of Veterinary Medicine and Biomedical Sciences brings new perspective to this question. A study conducted by the Dog Aging Project (DAP) of more than 27 companion dogs found that purebred and mixed dogs were generally equally likely to experience various diseases. Although some breeds may be more susceptible to certain diseases, the overall diagnosis rate is virtually the same between both groups. The Dog Aging Project's chief veterinarian, Dr. Keith Creevy, notes that there are several well-known diseases that are more common in certain breeds of dogs, which supports the notion that purebred dogs are more susceptible to disease. ... >>

Random news from the Archive

The laser will take the missile away from the target 26.10.2010

Preparing for the wars of the present and future, the Americans do not get tired of developing means of protecting their military personnel. Helicopters are now successfully replacing cavalry, providing the transfer of troops over long distances. And they fight them with the help of small rockets equipped with a heat sensor to accurately hit the engine.

How to protect a helicopter from such a missile? Another method was proposed by University of Michigan professor Mohammed Islam, who founded his company and received a one million dollar grant from the army agency DARPA to create production.

At the heart of the protection is a supercontinuum fiber laser operating at medium infrared frequencies. Such lasers in the visible range emit light in a wide range of wavelengths. An infrared laser with a similar wide spectrum creates the illusion of a warm object, and the rocket flies towards this phantom, and not towards a real helicopter.

The laser created by Professor Islam, unlike other examples of such protection, has no moving parts, which reduces the price and increases reliability.

Other interesting news:

▪ The ozone layer is recovering

▪ The existence of the ninth planet is proved

▪ GTX Titan accelerator with cooling system from Gigabyte

▪ Interactive TV Hybridcast

▪ DDR3 Ultra Low Profile (ULP) Planar Mini-UDIMM 8 GB

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Parameters of radio components. Article selection

▪ article by Robert Browning. Famous aphorisms

▪ Why is aluminum foil glossier on one side than the other? Detailed answer

▪ article Leader of a group (theatrical, amateur), leader of an amateur association, leader of an orchestra (ensemble). Job description

▪ article Amplifier on the chip TDA2822, 2x0,65 watts. Encyclopedia of radio electronics and electrical engineering

▪ article Chipsets for building Spread Spectrum devices. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews