ATB distribution center: bringing warehouses out of the shadows
ATB is a chain of grocery stores that has been on the Ukrainian market since 1993. It has its own logistics system using regional distribution centers.
For a new distribution center in the town of Vasishchevo, near Kharkiv, we created a complex energy-efficient solution for lighting and electricity distribution, which ensured comfort and increased work efficiency.
Our task was to design and build a system of efficient distribution of electricity and lighting. We were based on the general requirements of ATB regarding the reliability of engineering systems and our own principles of building efficient electrical systems.
Before starting the design, we carefully studied the technological process of the distribution complex, initiated a dialogue with related organizations, pre-agreed on the principles of construction of all engineering networks, and thus obtained the concept of power supply and lighting. Our approach to the efficiency of engineering networks took into account the following key elements:
- The total cost of all systems at the construction stage: the cost of the equipment, the term and the cost of its installation.
- Total cost of ownership: electricity costs, ongoing maintenance and repairs.
- Impact on safety and labor productivity during technological operation.
As a result, we received a Distribution Center of a completely new engineering and aesthetic class. It used more effective solutions compared to those generally accepted in the industry:
the total cost of the estimate is 25-30% lower than the industry averages, per 1m2;
the term of construction of electrical and light engineering systems was reduced by almost half;
engineering reliability of solutions has significantly increased;
the quality of the systems has increased, including due to the use of materials and components exclusively from European and North American brands.
Even at the pre-project stage, we ensured almost seamless cooperation of the participants in the construction engineering process.
Our specialists studied the world experience in the construction of light scenes of logistics centers and took into account the specific experience of the customer regarding the operation of distribution centers.
When preparing for lighting design, we took into account the wishes of workers and managers, since neglecting the impact of light on the emotional state, concentration and attentiveness often leads to negative consequences: staff turnover, an increase in operational errors and even accidents.
With this in mind, we created a lighting scheme that not only technically met lighting standards, but also contributed to increased safety and work productivity. Zones with different technological operations had different types of lamps, optical systems and different powers in order to adapt the levels of illumination, uniformity, and color rendering to technological needs.
Having adopted the experience of operating similar distribution centers, we took into account numerous features: from the placement of cable routes and lamps to the prevention of condensation in electrical appliances of cold zones of the complex. In addition, our power distribution concept also involved the creation of a specification for a company that manufactured a transformer substation.
For the design and construction of the distribution center, we applied the “process synchronization” approach. The key principles of building the systems were fixed at the very beginning, and the main electrical design took place in parallel with the construction. This reduced the total period of implementation of the works by at least half, and also made it possible to immediately receive project documentation that corresponds to the actual object. The Tesla Gigafactory, for example, is being built using the same approach.
Logistics complexes of this class have two independent power inputs. There are two main types of load switching organization between them. Operation from one of the branches as the main and switching to backup or simultaneous load of both. We chose the method of parallel operation of both transformers with a load of 50% of the power and the division of the low-voltage part of the TP into two parts. Thus, in case of loss of voltage on one of the power supply branches, automatic input of reserve and redistribution is applied — the second input is loaded at 100%.
The simultaneous operation of the complex from two inputs is much more reliable, because they do not work at full power. The service life of such transformers is longer, and the time to switch in case of power loss is insignificant.
Such objects always require a guaranteed supply of electricity, most often through diesel generators. After all, in case of loss of voltage at two inputs, the electrical system must ensure uninterrupted functioning of the technological cycle.
After analyzing the scenarios of the use of engineering systems connected to the guaranteed power supply, we came to the conclusion that it is advisable to use two synchronized diesel generators instead of one. At the moment when backup power needs to be applied, they are turned on at the same time, but all the power is distributed to the first one, and the second one works at minimum load. This decision increased the reliability of the system and significantly reduced fuel consumption.
When building the automatic input of reserve on the DES, we took into account that not all systems need a backup guaranteed power supply, and the time to switch to a backup power source is not critical for a number of systems. That’s why we divided the various systems into 6 AVR devices: ventilation equipment, refrigeration, charging stations, emergency lighting, server and computer equipment, fire extinguishing pumps. We also adjusted the switching sequence in such a way that the starting of the systems did not occur simultaneously and did not overload the operation of the diesel generator.
Abandoning the general AVR and dividing it into 6 separate devices significantly increased the reliability of the system and its maintainability.
In addition to the general requirements of reliability and compliance with fire regulations, our engineers had to arrange the system of input and distribution devices and AVR at the DES in such a way as to place it in a panel room with an area of 13 m2. Emergency lighting backup battery systems had to be installed nearby.
It was an almost impossible task, but we succeeded.
Emergency lighting is a mandatory part of the building lighting system. Most often, it is implemented with the help of battery units inside the lamps or individual additional lamps. The use of a large number of battery units is costly both during construction and during maintenance. They should be replaced every 2-3 years.
We completely abandoned the use of battery units located in emergency lighting fixtures and created a centralized battery system. This ensured uninterrupted power for the time when the switchover to the diesel generator is taking place. We also connected BMS — distribution and computer networks — to the central battery unit.
In this way, we increased the reliability of the system and significantly saved the construction budget, because there was no need to complete the lamps with batteries, in the amount of more than 500 pcs. We have approximately halved the cost of emergency lighting.
We understood that a large number of qualitative changes in engineering networks and communications will lead to the emergence of additional needs and wishes of the customer, which will require the laying of new networks. Anticipating this, the design and engineering team changed the approach to the construction of cable drainage systems. We laid a cable tunnel with a width of 1.5 m and a height of 1.8 m in the section from the switchboard to the main distribution well.
It was quite a difficult task to evenly illuminate the entire area, because the distance between the perimeter and the facade of the building reached 100 m. In this gap, we could not install lighting poles, because they are very easy to knock down, and it would be dangerous for drivers. Therefore, for outdoor lighting, we selected lamps with specific optics that provided the necessary levels of illumination.
A feature of conducting electrical installation work in logistics complexes is the performance of a significant number of operations at great heights using lifting mechanisms. This significantly increases the costs and deadlines of the project, so we began to look for the possibility of optimizing and reducing these operations.
The racking equipment in the ATB logistics center was up to 12 m high, and the height of the luminaires in the high area was 14.75 m. Traditionally, in this case, HIGH-BAY lamps are used for high spans, and an electrical tray with cables is laid between the racks, each lamp is connected separately through junction boxes.
When we analyzed the expediency of following this model, we realized that it has flaws:
- If several units of lifting equipment work simultaneously in the inter-rack space, shadows are formed at great heights, which are dangerous for technological operations.
- This model does not provide sufficiently uniform lighting at different heights and distances from the lamp. Such changes during a long work shift are very tiring for employees.
- At the installation stage, the standard approach requires a large number of operations and time: one inter-rack line (there were more than 40 of them) was installed within a week.
With deep engineering experience and our own lighting development and manufacturing capabilities, we modified one of our lines of lamps, which allowed us to completely abandon the laying of cable routes in the trays between the racks. We have developed a quick-to-install continuous line of lamps that meet the IP protection level required for warehouses. In this way, the installation time was reduced by 7-10 times, and the amount of materials for installation work was reduced by almost half. In total, the complex saved several million hryvnias.
To implement project tasks, we have developed a special modification of the NL Sires W line main light. It has a narrow-degree optical system covered with transparent glass, main 6-wire internal wiring, which allows you to group the inclusion of lights in the mode of 25, 50, 75, 100%. The lighting system has a separate power line, emergency lighting groups and IP65 degree of protection.
Luminaires are quickly mounted in the trunk line using prepared mechanical and electrical connections. Regardless of the height of their location – whether at 1.5 m or at 14 m – the vertical illumination of the surfaces is very uniform and equals 350-500 lux over the entire height of the racking equipment, which is the best level from the point of view of the efficiency of work processes and long-term concentration illumination
The design of the modified lamp allows repair work to be carried out without turning off the line. We simply disconnect the optical part of the lamp from the special mount and carry out repairs, which are very simple and quick.
Usinng such lamps, we got bright warehouses, at the level of office premises. At the same time, electricity consumption did not increase, it remained approximately the same as when using HIGH-BAY.
We worked on the project to the final stage for about 6-7 months, although it usually takes 14-20 months. This speed is due to the “synchronization of processes” and the fact that we independently cooperated with related organizations that installed tangential engineering networks: water supply and drainage, heating, air conditioning, ventilation, etc.
Thanks to the above solutions, we have reduced the number of corrections, revisions, and possible inconsistencies that contractors are constantly faced with.
Our complex energy-efficient solution for lighting and electricity distribution made it possible to reduce the construction period, guarantee the quality and reliability of engineering networks, increase the efficiency of workers and save the customer several million hryvnias.