Renovation and upgrading of the existing power supply system of the Business Center

Feb 9, 2022

This project was implemented in three stages. At the first stage, we conducted an inspection of the existing power supply system. At the second stage, we selected an optimal solution to address the main issues identified during the inspection. And we also made a design and coordinated the project and estimates with the customer. At the third stage, we implemented the project. Please see a step-by-step implementation of the project below.

The results of the inspection of the power supply system of the BC building

Necessary for the life support of the building. Such as:

  1. The main distribution board is fuse-based. According to the owner of the business center, the disadvantage of this board is the need to ask an electrician for maintenance, since in the event of a blown fuse, it can be replaced by a qualified electrician only. An electrician visit to replace the blown fuse takes quite a long time, which pauses the activities of tenants;
  2. The fuse ratings are not selected correctly in relation to the cross section of the outgoing cable lines. The maximum permissible fuse current, in some cases, is several times higher than the maximum permissible cable current, i.e., if the line is overloaded for a long time, the fuse will not blow, but the cable is overheated, and cable insulation can melt or ignite;
  3. Poorly made installation;
  4. The electrical circuit of the board is missing;
  5. Cable tags are missing, outgoing lines are not marked.

Photo 1. The main distribution board (MDB) of the building

Tenants’ distribution board (DB 1) (Photo 2):

  1. This board completely lacks differential protection to protect people from electric shock and from fire. This protection is necessary as required by fire safety regulations and regulations for electrical installations;
  2. The automatic circuit breaker ratings are not selected correctly in relation to the cross section of the outgoing cable lines. The maximum permissible automatic circuit breaker current, in some cases, is higher than the maximum permissible cable current, i.e., if the line is overloaded for a long time, the automatic circuit breaker will not break, but the cable is overheated, and cable insulation can melt or ignite;
  3. Poorly made installation;
  4. The electrical circuit of the board is missing;
  5. Cable tags are missing, outgoing lines are not marked.

Photo 2. Tenants’ distribution board (DB 1)

Tenants’ distribution boards (DB 2, DB 3) (Photo 3):

  1. This boards completely lack differential protection to protect people from electric shock and from fire. This protection is necessary as required by fire safety regulations and regulations for electrical installations;
  2. The automatic circuit breaker ratings are not selected correctly in relation to the cross section of the outgoing cable lines. The maximum permissible automatic circuit breaker current, in some cases, is higher than the maximum permissible cable current, i.e., if the line is overloaded for a long time, the automatic circuit breaker will not break, but the cable is overheated, and cable insulation can melt or ignite;
  3. There are no electricity meters for tenants;
  4. Poorly made installation;
  5. The electrical circuit of the board is missing;
  6. Cable tags are missing, outgoing lines are not marked.

Photo 3. Tenants’ distribution boards (DB 2, DB 3)

Automatic transfer switch (ATS) board (Photo 4):

  1. This board is designed to automatically switch to a backup diesel generator in the event of a voltage loss from the city central mains and to automatically switch off the generator and resume power from the central mains;
  2. At the time of inspection, the board was disassembled, not working;
  3. Poorly made installation;
  4. The electrical circuit of the board is missing;
  5. Cable tags are missing, outgoing lines are not marked.

Photo 4. Automatic transfer switch (ATS) board

Backup diesel generator set (DGS) (Photo 5):

  1. According to the existing connection diagram, a DGS must fully supply the entire business center with electricity. During the inspection, it was revealed that the DGS capacity is not enough for the entire business center;
  2. DGS grounding circuit is missing;
  3. Poorly made installation;
  4. Connection diagram is missing;
  5. Cable tags are missing, outgoing lines are not marked.

Photo 5. Backup diesel generator set (DGS)

General comments made during the inspection:

  1. BC grounding circuit is missing;
  2. There is no uninterruptible power supply for security and fire alarm systems, CCTV;
  3. There is no protection against high and low voltages, phase distortion, overvoltage at the main terminal (BC power supply line from the city mains);
  4. The BC reception is powered from the tenant’s wall outlet circuit, therefore, the electricity bills from the reception are paid by the tenant.

Solution

We have selected the optimal solution to address the identified issues, with due regard to the financial capacities of the customer:

  1. Replace the main distribution board (MDB) with a new modern factory-built custom-made board based on our design. The new board has a built-in automatic transfer switch (to diesel generator), protection against high and low voltages, overvoltage protection, indication of input phases, and automatic circuit breakers (see MDB drawing);
  2. Replace the tenants’ distribution board (DB 1) with a new modern factory-built custom-made board based on our design (see DB 1 drawing);
  3. Install electricity meters in individual wall-mounted enclosures for tenants’ distribution boards (DB 2, DB 3);
  4. Install additional controlled switches to disconnect air conditioning units, snowmelt systems when the BC is powered by a diesel generator. Thus, we have reduced the total power of the BC to the nominal power of the existing diesel generator;
  5. Install a grounding system for a diesel generator;

MDB drawing

MDB drawing

For AQTech website

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