The whole scope of electrical installation works is split into four stages.
First stage - arrangement and preparation for electrical installation works. At this stage following activities must be carried out before starting work at Site: work execution plan completed, working documentation for electrical installation work received; engineering and technical workers and foremen have familiarized themselves with the working documentation, cost sheets and organizational and technical solutions of the work execution plan. Following has to be approved: delivery schedules for equipment, products and materials with regard to technological sequence of works, list of electrical equipment to be installed with the involvement of installation vendor’s supervision personnel, conditions for transporting heavy and large-sized electrical equipment to the installation site. Premises must be prepared and accepted for accommodating teams of workers, engineering and technical personnel, for production base, as well as for storing materials and tools with provisions for labor protection, fire safety and environmental protection. Civil part of the electrical equipment installation site must be accepted under an acceptance certificate and during work activities all measures must be taken for labor protection, fire safety and environmental protection as per applicable rules and regulations.
Second stage - electrical installation works are usually split into two steps. Step one - supporting structures are mounted inside buildings and facilities for the installation of electrical equipment and busbars, hidden electrical wiring is routed, grounding networks and external cable networks are installed. All these procedures must be carried out simultaneously with the main civil work (as per combined schedule). Second step consists of direct installation of electrical equipment, routing cable, wires and busbars to required points. Electrical units should be installed as complete blocks when equipment is delivered in prefabricated modules which do not require straightening, cutting, drilling or other fitting operations and adjustment during installation.
Third stage - commissioning activities. Commissioning is a range of activities which includes inspection, adjustment and testing of electrical equipment in order to ensure the electrical parameters and modes specified by the project. Commissioning of electrical devices is carried out in four steps. During the first (preparation) step, the commissioning company must: develop commissioning execution plan; give their observations to client on the electrical installation works execution plan, identified in the course of developing the commissioning execution plan; prepare a set of metering equipment, test equipment and fixtures. During second step the commissioning company tests the installed electrical equipment while individual devices and functional groups are energized from test circuits. This work step can be combined with electrical installation works at Site. Start of commissioning work at this step is determined by the degree of readiness of civil and installation works: in electrical rooms, all civil work, including finishing, must be completed, all openings, wells and cable channels must be closed, lighting, heating and ventilation completed, electrical equipment must me completely installed and grounded. During third step of commissioning - individual tests of electrical equipment are carried out. The beginning of this step is considered to be the start of the operating mode at this electrical unit, after which commissioning should be related to the work performed in operating electrical units. During this step the commissioning company adjusts the parameters, protection settings and characteristics of electrical equipment, tests the control, protection and alarm circuits, as well as idle electrical equipment in preparation for individual testing of process equipment. During fourth step of commissioning integral testing of electrical equipment is carried out as per approved plans. During this step commissioning is aimed at setting up the interaction of electrical circuits and electrical equipment systems in various modes. Fourth step of commissioning is considered completed after the electrical equipment reaches electrical parameters and modes set by the project, which ensure stable technological process for manufacture of the first product batch in the amount set for the initial period of gaining the design capacity of this facility. The commissioning company work is considered completed subject to a signed commissioning acceptance certificate.
Final stage of the range of electrical installation works is the acceptance test and handover of the facility for operation. Before handover for operation the electrical installation companies create a technical commission from among their engineering and technical workers and experienced foremen. The technical commission is headed by the chief engineer of the company. The technical commission checks the quality of the electrical installation works on the facility to be handed over for operation and creates a punch list. After faults and defects have been remedied, the electrical installation company acting as contractor gives a written notice to the general contractor about the readiness of the electrical units of the facility for presentation to the working commission. Working commissions are appointed by the decision of the Client. Working commissions include representatives of the Client - the chairman of the commission, the general contractor, subcontractors, the operating company, the general designer, the state sanitary supervision authorities, the state fire supervision authorities, etc. After the working commission has carried out the necessary checks (in accordance with SNiP 3.01.04-87), the final acceptance into operation by the state acceptance commission is carried out. Acceptance for operation of completed facilities by state acceptance commissions is formalized by Certificates.
For cables with voltage of 0.4 kV experience padded and shifted the cables before switching on and after maintenance. Test cables for voltage up to 1 kV for the balance sheet not regulated. Therefore, tests are carried out in accordance with the EMP and pteep once in 1-2 years.
For cables with voltage of 6-10kV:
Line up to 60 m in length, which is the conclusions from transformer substations to overhead lines, may not to experience.
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