Acceptance and supervision of electrical works
To ensure the quality of the work, the monitoring and acceptance is very important. This work must be done closely and throughout from the beginning to the completion of the work:
I. STEPS FOR ACCEPTANCE OF ELECTRICAL WORKS
Consists of 3 steps:
- Step 1: Cold acceptance of materials, equipment, and work volume before connecting to the power grid system.
- Step 2: Acceptance and energizing the work.
- Step 3: Acceptance and handover of the project.
II. COOLING WORKS:
Legal documents include:
- List of materials and equipment.
- Equipment factory inspection sheet.
1. Testing and acceptance of medium voltage lines:
- Check poles, column foundation, anchor foundation, anchor wire, grounding.
- The beams, porcelain, grounding flags of the poles, the base of the poles, the distance between the live part and the grounding part.
- Check the cross-sectional measurement and DC resistance of the conductor.
- Check the line corridor.
- Check elevation, phase-earth distance.
- Circuit breakers, cutters, measuring points
2. Substation acceptance test:
- Inspect columns, column foundations, beams, supports, operating platforms, climbing ladders.
- Check valve lightning protection, self-falling fuse, fuse-link rated current.
- Checking the transformer includes: oil level, desiccant, pressure tap, machine face gasket, oil discharge umbilicus, radiator impeller.
- Check the power cable connecting from the transformer to the low voltage cabinet.
- Check low voltage cabinets include:
+ Power metering system, circuit diagram.
+ The total and branch circuit-breakers: check the closing and breaking operations, the allowable breaking current value.
+ Check the working grounding system, low voltage lightning escape system.
- Check the TBA grounding system.
3. Testing and acceptance of low-voltage lines:
- Check poles, column foundations, anchors, anchor wires, grounding, line accessories such as clamps, clamps.
- Check and measure the cross-sectional and DC resistance of the conductors and power cables in the meter box.
- Check the metering system.
- Check the line corridor.
- Check elevation, phase-earth distance.
4. Testing and acceptance of switchgear:
4.1. Testing and acceptance of segment cutting station:
- Check the input and output porcelain.
- Check the distance between live parts and earth.
- Check the ground value.
- Check closing and cutting operations.
- Check relay system, control cabinet.
4.2. The work of acceptance of the load knife:
- Check the arc extinguishing chamber.
- Check the distance between live parts and earth.
- Check the ground value.
- Check closing and cutting operations.
- Check the drive system.
4.3.Isolation knife acceptance test:
- Check blade contact.
- Check the distance between live parts and earth.
- Check the ground value.
- Check closing and cutting operations.
- Check the drive system.
III. ELECTRICAL COLLECTION WORKS:
After overcoming all the shortcomings detected in the cold acceptance step, which means that the whole project has met the operating standards and conformed to the design, the hot acceptance test of the project will be carried out.
Acceptance and energization of the works for the purpose of comprehensively general inspection of the work to see if it ensures the operational specifications of the works, to see if there are any shortcomings and errors that the cold acceptance test did not detect. out.
When taking over and energizing, it is mainly checking and observing technical parameters of equipment and power grid shown on the metering system and protective relay system.
1. Acceptance and energization of medium voltage lines:
- Check all equipment on the line to ensure power-on conditions.
- Close the power and check the line and attached equipment within 24 hours.
2. Testing and acceptance of energizing substations:
- Check all substation equipment to ensure power-on conditions
- Power on the transformer without load for 72 hours.
3. Acceptance and energization of low voltage lines:
- Check all equipment on the line to ensure power-on conditions
- Close the power line without load for a period of 24 hours.
- After the investor completes all the procedures such as the power purchase agreement and legal procedures, the new project can be energised and officially operated commercially.
- When the work has not been handed over, it is temporarily handed over to the forest management and operation unit.
IV. ACCEPTANCE HANDLING WORK OF CONSTRUCTION ASSETS:
After energizing for 24h or 72h safe acceptance and after clearing all shortcomings, the construction unit will hand over the work and guide the operation to the operation management department to receive from the investor.
The parties who sign to confirm the safe energizing and load testing work agree to complete the acceptance test and put the work into operation. The investor is responsible for managing and operating in accordance with the electrical equipment process, according to the equipment operating instructions of the manufacturer.
