Insulating rod: types, description, purpose

The electrician is one of the most dangerous professions. In order to maximize the safety of personnel, the company provides its overalls and footwear with protection from electric arc. To this, personal protective equipment (PPE) and a professional power tool are also provided . Particular attention is paid to work under stress and at altitude. For this, workers are provided with additional equipment with protective properties from the electric arc. These include safety harnesses, ladders, mats. One of the interesting devices, which can be attributed to the means of individual protection and to tools, is an insulating rod.

What does it do? This type of equipment allows you to work with electrical installations that are under voltage, but not more than 550 kV. Depending on the functionality, these tools are divided into two main types. There is an operating and measuring rod. Their features we will discuss later in this article.

Design features

The tool is a stalk, which can be divided into three segments. It is a handle, an insulating, and also a working part. Such a tool for an electrician can be assembled or telescopic. The main thing is to provide the insulating element with a strong link grip. For this, special metal fasteners can be used, but their total length should not exceed five percent of the length of the insulating part.

The working tip is made of metal or some dielectric material and, depending on the purpose, can have a different shape and functional.

The insulation part is made of materials that do not conduct current. For example, it can be ebonite, bakelite, wood and others. By technology they are thoroughly boiled in linseed or hemp oil, dried. After that, the top is covered with an insulating varnish to protect it from penetration of moisture inside.

The handle is usually made of the same material as the insulating part. A restrictive ring must be arranged between these sections, which, during operation, will prevent the hand and the insulating section from touching. The limiter should protrude at least ten millimeters and have a height of at least three millimeters.

The total length of the rod according to state standard number 20494-2001 ("Insulating rod operational and elements of portable grounding - technical conditions") depends on the voltage of the electrical installation on which work is performed.

In installations with voltages greater than 350 kV, tools are used for the operation of two electricians using a supporting device.

Main settings

Weight of equipment for the work of one person should not exceed eight kilograms. The force per arm for measuring rods should not exceed 80N, for other species up to 160N. The length of the insulating part and the handle depends on the voltage value, according to GOST 20494-2001.

Scope of the elements

Work under stress with a rod can be carried out in closed electrical installations, or outdoors, but in dry weather. Never use this appliance in rainy, snowy weather or during fog, frost. In such weather conditions, there is a high risk of electric shock, which in some cases can lead to fatal consequences.

With the help of this tool, operations are carried out with disconnectors, replacement of fuses, installation of discharger parts, checking isolations on power lines and substations, applying overlapping grounding, using as a means of relieving an injured person from electric current, and making measurement work.

The modifications and possibilities of each species should be considered in more detail.

Operational bar

There are four types of basic functionality:

• SHO (operational isolating). Used for a large number of works due to a replaceable head. Applied to electrical installations with voltages up to 220 kV with direct or alternating current.
• SCO (rescue). With its help, you can rescue a person from the zone of electric shock with a voltage of up to 110 kV. Emergency measures for release increase the chances of reanimating the victim.
• SHOW (insulating rod universal). Used in electrical installations of similar SHO. At the same time, the maximum number of replaceable working parts increases the functionality.
• SPD (grounding overlap). Also used on electrical installations with voltage up to 220 kV with direct or alternating current. This device allows you to approach areas with residual voltage or partial shutdown of the installation. At the expense of working with SPZP the amount of electric trauma is significantly reduced.

The operational bar allows you to perform the necessary work under tension. This eliminates the risk of electric shock. The main thing is to observe the rules of operation, testing and testing of PPE.

«Mites»

Separate position should be isolated insulating pliers. The element allows replacement of fuses in electrical installations up to 1 kV and higher. They are also used to remove heads and fences in installations up to 350 kV inclusive. It is possible to replace this type of equipment with a universal operating rod, with a suitable working head.

The size and weight of this equipment should provide a comfortable work for one person. The insulating part and the handle must be made of materials having dielectric and antistatic properties.

The mites themselves can be made of electrically insulating materials or metal. On metal sponges should be put on oil-and-petrol resistant tubes in order to ensure that the work does not damage the surface of the cartridges.

The length of the insulating mites also depends on the voltage value:

• With a voltage of 1-10 kV, the length of the insulating section is 450 mm, the grips are 150 mm.
• At a voltage of 10-35 kV the length of the insulation section is 750 mm, the handles are 200 mm.

Measuring

Using this professional power tool, it became possible to determine the jumps, the voltage drop on the parts of the electrical installation in the normal operating mode. There are two methods: by measuring the temperature of the contacts or by directly measuring the voltage jumps.

The measuring head is a spark gap configured in the laboratory. The minimum allowed value is set. The working head, through a parallel connection to the area under test, with the help of indicators, indicates the presence or absence of voltage. It is important that at the time of monitoring the electrical installation is in the normal operating mode.

There are three main types:

• SHIU. In this device, it is possible to change the distance between the electrodes, which allows the most accurate measurement data.
• SHI. In such devices, an arrow micro-ammeter with an additional resistance of up to 160 megaohms is installed. Depending on the method of measurement, a set of test leads with conductors is changed on the work site, which are connected to the clamps. Probes are placed on a controlled insulator, a parallel connection occurs. The arrow of the microammeter shows the result of the measurements.

The device is used for the second method. The test probes are installed to measure the temperature at the contacts.

• Electrical clamps. It is a current transformer with a detachable magnetic circuit. For the primary winding, a conductor with a measured current is used, and the secondary is closed to a measuring device, either switch or digital.

Operational conditions

The insulating rod should be used in an external environment with a temperature regime from minus 45 ° C to plus 40 ° C at a relative humidity of 98% at 25 ° C.

Do not use appliances:

• Not having the appropriate certificates, and not passed the test, respectively, not meeting the safety standards.
• Defective. Such devices must be repaired. After that tests were carried out. And only on the received data the decision on the further use or recycling of the device is made.
• At high humidity. In wet weather.
• With the use of supports (ladders) for measuring work.

Work on electrical installations is allowed for workers who have the appropriate tolerances. Each employee must be equipped with a complete set of PPE, including dielectric gloves, dielectric boots, protective clothing with electric arc protection, safety goggles and a respirator. All this will help to protect the worker from electric trauma as much as possible.

Before work, the insulating rod must be visually inspected. If a fault is found, it must be replaced by another instance.

In operation, mechanical tests are not carried out. Can be planned and unplanned when the device falls, flaws are detected. Preliminary, the device is repaired.

Testing

Since work on an electrical installation is classified as hazardous, the tool for an electrician is carefully inspected and monitored. Moreover, depending on the equipment at the manufacturing plant, tests are carried out. According to GOST 20494-2001 they can be:

• Acceptance. Carry out for each product.
• Periodic. Every bar should be exposed.
• Typical. Three samples of the same species are selectively tested. It will be necessary to conduct all kinds of tests.

All testing activities are carried out by the manufacturer with the help of specially trained people who have a certain level of admission and who have been trained and certified. These operations must be performed in a timely manner, the life and health of the electrician depends on this.

The list of tests:

• Visual control. Verification of completeness, marking, packaging. The availability of the required documentation and compliance with the required safety is checked.
• Verification of compliance with factory drawings. Produced with the help of measuring instruments, there must be a complete match of the parameters.
• Checking the electrical insulation for strength. Generate a voltage of an alternating current of an industrial frequency by a single application for not more than five minutes. In this case, increasing the voltage to 1/3 of the value can be arbitrary. Further increase should be smooth. The working and insulating parts of the rod are inspected. In the event that it is not possible to carry out the test with a full measuring section, then this part of the rod is checked by pieces. If breakdowns, local heating from dielectric losses, surface discharges are not detected, then it is considered that the product has successfully passed the test.
• Tear test. One end of the rod is fixed, the other with a load or winch subjected to an allowable load. The test was successful in the absence of visible damage.
• Bending test. The product is fixed horizontally at two points near the restrictive ring and the end of the handles. The rod sample was tested in the absence of visible damage.
• Checking the greatest effort on hand. The horizontally fixed rod is fixed with two points - the front (50 mm from the restrictive ring) and the rear (50 mm from the end of the handle) supports. Measurement is carried out on the front support and the indicator should not exceed 160N. The isolating rod up to 1000V is not subjected to this kind of tests.

If the result is negative, repeat the procedure with a large number of samples. In the event that the data is repeated, the entire product is seized and the production of a new batch is prohibited until the causes of negative indicators are clarified and eliminated. In such situations, the test stamp is crossed out with a red line.

All tests are performed in accordance with the regulations in force. For operational devices, tests are performed every two years, for measuring instruments - once a year.

Choice of equipment

In order for the employee to be provided with a properly selected PPE and tool, the relevant government standards and norms should be studied. This will help to choose the right kit for each type of work.

The price fixed on insulating rods will play an important role for the consumer in the matter of choosing the device. On average, it is 500 rubles. But do not chase cheap devices. It is necessary to carefully study the warranty obligations of the manufacturer and the package of documents provided to them. All products must pass pre-sale tests and have a corresponding stamp.

The result

In conclusion, I would like to note that the modern world does not think of itself without electricity. So, you can not do without measuring bars. It is hard to imagine what will happen if the supply of electricity is cut off all over the world. Probably, there will be chaos and panic. Therefore, it is necessary to treat with great respect and respect people serving electric installations, and the appropriate authorities to provide them with all necessary means of individual protection.

So, we found out what a technical tool like an isolating rod is.