Rhenium Alloys,Tungsten Rhenium Wire,Rhenium Alloys Composition,Tungsten Rhenium Alloy Density Shaanxi Xinlong Metal Electro-mechanical Co., Ltd. , https://www.cnxlalloys.com
What is the power distribution equipment system? How to debug the power distribution equipment system
**First, the Power Distribution Equipment System Introduction**
Power distribution systems are essential components in electrical engineering, typically referred to as distribution rooms, distribution cabinets, or distribution boxes. These devices are used for measuring and controlling electrical energy and consist of busbars, switchgear, protective devices, and measuring instruments. The layout must meet operational requirements, ensure ease of maintenance, and guarantee safety for both personnel and surrounding equipment. They are commonly located in power plants, substations, and other similar facilities.
In electrical projects, the installation of a power distribution box (or panel) without any adjustable components does not require commissioning. However, if a distribution box in each user room is equipped with electromagnetic switches, leakage protectors, or other adjustment components, it may need commissioning. If the manufacturer has already calibrated these components according to standard parameters, the installation unit and user can directly use them without self-adjustment, and no commissioning cost will be incurred.
For systems that require commissioning after installation, the construction and installation unit should perform the necessary debugging. This process must follow technical specifications, be documented, and costs calculated based on established quotas. During the bidding phase, since specific electrical equipment like distribution boxes may not yet be ordered, it is difficult to determine in advance whether the installation company will handle the commissioning. This uncertainty can lead to discrepancies in bid pricing, causing confusion among bidders. Therefore, it is recommended that, for such projects, the commissioning fee for the distribution system be temporarily included in the budget, clearly stated in the budget statement or contract, and adjusted later during project settlement.
Electrical commissioning is a complex and technically demanding task that requires high professional expertise. It is important to take the cost of each electrical professional seriously and make every effort to master the necessary skills.
**Second, the Content of Electrical Commissioning for the Power Supply and Distribution System**
The electrical commissioning of a power distribution system includes both the primary circuit (such as circuit breakers, isolating switches, current transformers, and reactors) and the secondary circuit (such as relay protection and measuring instruments). This commissioning process typically considers general relay protection devices, such as overload and short-circuit protection, but excludes special protection and automatic device testing.
Commissioning of the power distribution system applies to busbar connections, busbar sections, and circuit breaker circuits. If busbar protection is installed, the busbar section breaker circuit must be commissioned separately, in addition to the main power distribution system. Commissioning of special protection devices—such as power direction protection, distance protection, and high-frequency protection—and automatic devices like standby power input and automatic reclosing is not included in the standard commissioning process. If these are used, they should be listed separately, matching the number of "systems" in the power distribution setup.
The commissioning of 380V and 3–6kV motor feed circuits (such as switchgear or switchboards) is included in the motor inspection and commissioning list. Transformer incoming lines (including factory transformers) to voltage distribution equipment at different levels are not considered part of the power distribution system; their commissioning is included in the transformer system. High-voltage power distribution equipment from the factory should be quoted from the 6kV main distribution busbar (if no transformer is used), and the power distribution system commissioning should be listed separately.
**Third, Commissioning Instructions for Transmission and Distribution Systems**
The commissioning of the power distribution system is calculated based on the "system" concept. The quantity calculation rule is determined by the number of circuit breakers that meet all of the following conditions: rated current of 100A or higher, not a transformer high/low side circuit breaker or motor control box, and not only used for maintenance isolation. Each unit project must calculate at least one loop of the power supply system for commissioning.
Commissioning below 10kV applies to power distribution circuits, such as from the power distribution device to the distribution box. However, the power supply from the distribution box to the motor is included in the motor system commissioning. The power supply system commissioning includes cable tests, insulation resistance testing, and circuit breaker and relay protection testing.
General instruments like voltmeters and ammeters, along with protection transformers, are included in the corresponding power distribution system commissioning. Metering instruments and transformers are verified by the power supply department, and their costs are accounted for accordingly. Switchgear and cable tests are already included in the power distribution system commissioning, so no further calculations are needed. Motor-powered cable and switchgear tests are included in the motor system commissioning. Dense busway commissioning to the power distribution system is also included in the power distribution system commissioning, while dense busway between distribution cabinets is counted under busbar commissioning. Transformer outlet dense busway commissioning is included in the transformer system and not separately calculated.
Commissioning is calculated per circuit breaker on one side. If there are circuit breakers on both sides, it is calculated as two systems. For power supply circuits with debugging components such as instruments, relays, or electromagnetic switches (excluding knife switches and fuses), commissioning is calculated accordingly. Mobile appliances and household devices connected via sockets are not counted if they are pre-adjusted by the manufacturer and do not require user adjustments.
In residential, school, office, hotel, and commercial buildings, the commissioning of distribution equipment depends on the power supply mode. Distribution rooms, boxes, cabinets, and main lighting distribution boxes with debugging components must follow the appropriate sub-assembly of “Distribution Equipment System Commissioning.†Even if electromagnetic switches are installed in user rooms, if the manufacturer has already calibrated them, no commissioning is required. Meter verification for civil use is handled by the power supply department, and no separate commissioning fees are charged.
**Fourth, How to Commission the Transmission and Distribution Equipment System**
High-voltage power distribution cabinets are calculated based on the number of sets used, with the quota professionally set. Low-voltage power distribution cabinets are not counted individually but are included in the commissioning quota below 1kV, covering all low-voltage power supply circuits. The power supply from the low-voltage distribution equipment to the distribution box is included, while the power supply from the distribution box to the motor is covered under the motor system commissioning.
The commissioning of the power distribution system includes full testing, such as cable testing and porcelain bottle pressure resistance. Circuit breakers and busbar section breakers in the power supply bridge circuit are considered independent power supply systems. The quota is calculated per circuit breaker on one side. If there are circuit breakers on both sides, it is counted as two systems. If a distribution box contains only a knife switch, fuse, or air switch without debug components, it is not counted as a commissioning system.