Improving the reliability of electrical equipment in industrial enterprises

Experience with the operation of electrical equipment of industrial enterprises shows that its actual service life and the time of operation until failure are 1.5 — 3 times less than the standard ones. All causes of premature failure of electrical equipment can be divided into three groups.

The first group is external causes. These include: a general shortage of electrical products, a shortage of specialized equipment, a low level of equipment repair, poor quality of electricity at electrical receivers, difficult working conditions, installation defects, lack of reliable protection of electrical receivers from emergency modes (up up to 75% of electric motors do not have reliable overload protection).

The second group of reasons is related to the implementation of project works.These are errors in the selection of electrical equipment in terms of design, operating modes and environmental conditions, wrong choice of protection, errors in substantiating the personnel structure, determining the equipment reserve fund.

The third group of causes is directly due to the activities of electrical services and personnel servicing machines and mechanisms used in production. This should include: insufficient staff and insufficient qualifications of electricians, violations of the rules for technical operation of electrical equipment, irregular maintenance and ongoing repairs, unsatisfactory operating conditions of electrical equipment created through the fault of service personnel (water penetration into mechanisms, pollution, etc.), poor technical equipment of electrical services.

Improving the reliability of electrical equipment is achieved through a number of organizational and technical measures.

Damage from power outages to electricity consumers can be reduced by coordinating the time and duration of planned outages, reducing the time for repairs of electrical equipment by power supply organizations by using progressive work methods, drawing up network schedules, rational use of labor, machines and mechanisms.

Increasing the reliability of power systems can be achieved by using deep entry, increasing the reliability and durability of electrical networks and, first of all, line insulators.An effective means is the sectionalization and use of backup power plants to supply the most critical users during emergency conditions. It should be remembered that such measures as using a reserve and reducing the length of radial lines are not always economically justified.

Increasing the reliability of electrical equipment, tools, and automation equipment can be accomplished primarily by placing electrical equipment in separate rooms that protect it from the harmful effects of the environment. It is recommended to seal the covers of electric motors, use special inhibitors, carry out preventive drying of the insulation of the windings of electric machines with the help of portable thyristor devices during breaks in operation.

Designs for electrical installations of industrial enterprises should be improved.

In electrical networks, it is necessary to improve the quality of the supply voltage and reduce its asymmetry. At the same time, the controlled electric drive should become the next step in the development of machines and mechanisms. It is recommended to purchase electric motors complete with starting protection and control mechanisms.

Issues of protection of electrical equipment from emergency modes are among the main ones for increasing its reliability and durability. It is recommended to replace thermal relays with two-phase protection elements with three-phase thermal relays. This will increase the reliability of the protection of electric motors in case of voltage imbalance.

It is necessary to introduce more widely special protections (phase-sensitive protection, built-in temperature protection, etc.), which, if correctly configured, will reduce the damage due to the failure of the windings of electrical machines by 25-60%. For more information on special types of protection, see here: Selecting the type of motor protection

It should be noted that it is difficult to select and configure protections in production conditions. This is due to the uneven loading of machines, metal-cutting machines and mechanisms, the wrong choice of electric motors in some cases, a strong influence of the external environment on the parameters of electric motors and starting protective devices. In such a situation, it is advisable to configure the protection of electric drives and other equipment at the installation site, if possible.

To increase the service life of electrical wiring in rooms with a polluted environment, it is recommended to carry out in channels with sealing of the outlets, to connect the wires by twisting and subsequent welding or pressing, use insulating tape of PVC type with pre- and post-wrapping of the structure with perchlorovinyl varnish. It is recommended to cover the metal structures with an anti-corrosion coating.

One of the important directions for increasing the reliability of electrical equipment is the timely and high-quality implementation of preventive measures organized by the electrical service. The available domestic and foreign experience shows that the planned preventive repair system of electrical equipment (PPR) is a fairly progressive form of maintenance and repair.

The economic efficiency of organizing the work of electrical engineering services according to this principle has been confirmed. Unfortunately, the SPR system is not widely used. The main direction for improving the existing system of maintenance of electrical equipment is the transition to a new strategy of maintenance of the current state... An indispensable condition for the use of such systems is the creation and implementation of diagnostic devices that allow solving the problem of monitoring the parameters of an electrical product by operating time and predicting the time of repair measures.

See also on this topic: What factors affect the reliability of electrical equipment