Electrical system inspection service

Electrical system inspection service

Why is periodic electrical system inspection extremely necessary?

Electricity has become an indispensable part of all fields today. However, the design and use of electricity today are also facing very dangerous risks. According to the report of the Ho Chi Minh City Fire Police, 76% of fires are caused by electrical short circuits.

Therefore, using electricity effectively as well as ensuring safety, and avoiding unexpected incidents that cause great damage to people and machinery is very necessary.

A. OTECH’s Electrical System Inspection Service

Understanding that problem, the team of experienced engineers of OTECH company has launched the service package “Comprehensive electrical system inspection” with the aim of:

• Determining the current status of your electrical system according to international standards and Vietnam standards (TCVN). From there, propose solutions to improve the reliability of the electrical system.
• Analyzing issues related to safety – grounding system.
• Analysis of backup power systems and procedures for handling power interruptions.
• Evaluate the selection of equipment in the power system according to short-circuit current.
• Evaluate the coordination of protection between levels.
• Measure and identify partial discharge (PD) phenomena on the medium-voltage system.
• Measure and identify overheating and overload phenomena on the system using infrared cameras.
• Evaluate problems related to power quality and solutions to overcome them.
• Evaluate the status and operating conditions of equipment.
• Evaluate problems related to the use of labor protection, existing maintenance methods and professional training for factory employees.

B. Implementation method

To provide a comprehensive picture of the customer’s power system, OTECH company offers the following steps for analysis and evaluation.

I. Analysis of electrical system structure issues:

1. Analysis of the customer’s grounding system structure

IEC 60364 standard stipulates grounding for the system. According to TCVN and in practice, most low-voltage electrical systems are connected according to the TN – C – S diagram, also known as the 3-phase 5-wire diagram.

With this diagram, the PE wire and the neutral wire (N) will run independently and have only one common connection point at the source. However, in reality, we still encounter the phenomenon of PE and N wires being connected repeatedly at the following points. This will cause the current from the neutral wire N to flow to the PE wire. At that time:

• The current on the PE wire increases.
• The ground fault protection occasionally operates but the cause is unknown.

With a team of engineers with many years of experience, OTECH company will help customers check issues related to the neutral point and the grounding system. Thereby ensuring the system operates safely and stably.

2. Check issues related to short circuits and equipment selection.

Nowadays, we can easily encounter electrical equipment that is only selected based on rated current and rated voltage, forgetting about short circuit current.

When choosing a closing device, we need to pay more attention to the short circuit breaking current of the device. The short circuit breaking current of the device must be greater than the maximum short circuit current passing through the device. Short circuit calculations are performed according to IEC 60909 standard to ensure the safety of the system when the device can easily cut off when an incident occurs.

3. Protection coordination calculation

Protection coordination calculation helps to selectively act when an incident occurs, avoiding wrong actions or actions beyond the level. When an incident occurs in an area, the equipment in that area will be isolated. It does not affect other load branches.

4. Partial discharge measurement (PD)

Partial discharge measurement (PD) is a solution to assess the discharge status on medium voltage cabinets.

The cause of partial discharge phenomena is due to the aging of insulation equipment, usually due to environmental impact. Partial discharge can be divided into two types:

• Surface discharge due to dust accumulation, and aging of insulation.
• Internal discharge of equipment due to air bubbles, and defects inside the product. Early detection of partial discharge phenomena will help customers completely prevent incidents before they occur.

5. Check for overheating phenomena with infrared cameras.

Nowadays, most production lines and buildings must ensure continuous power supply. It is very difficult or almost impossible to stop the system from performing periodic maintenance work.

The solution of using infrared cameras to assess overheating and overload phenomena, if any, it will help customers be more proactive in maintenance work, promptly preventing heat and explosion incidents before they occur.

6. Assessing issues related to power quality

The final step in Circular 39 of the Ministry of Industry and Trade and IEEE 1159-2004 clearly stipulates issues related to harmonics and power quality in the power system. Harmonics or power quality issues cause phenomena such as overheating of equipment, and trip protection devices of unknown causes, seriously affecting production and business activities.

Using specialized measuring equipment, OTECH’s team of engineers will help customers assess issues related to harmonics and power quality on the system.

From the results of that analysis, we will propose solutions to solve the above problems.

7. Determine issues related to the operating conditions of the equipment

Issues related to old, discontinued equipment and solutions for replacement.

Physical condition of the equipment.

Equipment operating conditions such as temperature, humidity, dust, and chemicals that oxidize equipment.

III. inspection of company health and safety policy and procedures

• PPE
• Maintenance plan
• Safety training issues
• Relevant technical documents

C. Detailed report

The detailed report of the “Comprehensive Electrical System inspection” solution package will include the following items:

• Abnormal findings in the electrical system.
• Short circuit reports and equipment selection in the system.
• Protection coordination calculation reports.
• Reports on partial discharge measurements on the MV system.
• Reports on overheating phenomena on the LV system.
• Reports on power quality problems and solutions to overcome them.
• inspection of the working environment conditions of the equipment.
• Proposals for maintenance and repair plans.
• Proposals for upgrading and replacement solutions to ensure the safe and stable operation of the electrical system.
• Proposals for backup equipment, training plans for staff, drawings, and documents required for the system.

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For more information about the electrical system inspection service, please contact:

OTECH JOINT STOCK COMPANY

• Hotline: 1800 9472
• Phone number: (+84) 28 6686 3565
• Email: service@otech.com.vn
• Address: 02 Street 15, Van Phuc 1 Residential Area, Hiep Binh Phuoc Ward, Thu Duc City, Ho Chi Minh City, Vietnam.