National Bank of Serbia
A consortium between Logstrup global partner, Log Design, and their partner Elgra Vision was awarded the contract for NBS (National Bank of Serbia) transformer substation reconstruction based on the „design and build“ conditions. Log Design was responsible for designing and equipment purchasing, while Elgra Vision was responsible for on-site electrical works.
National Bank of Serbia
Founded in 1884, The National Bank of Serbia is the central bank of Serbia and the sole issuer of Serbian banknotes and coins. From the very beginning, the bank was considered to be a modern banking institution. Today, the NBS data center supports all the banking and financial transactions within Serbia. At the time this project was carried out, the existing MV switchgear and LW switchboards had been in operation for 30 years.
During the tender process, Log Design had the possibility to go for one official inspection to the National Bank of Serbia in order to investigate all variables at the site. What they found was that the transformer substation is 10/0.4 kV, with 6 transformers with a rated power of 1000kVA. Two diesel generator sets of 630kVA are sources for standby power supply. Log Design's scope of supply was planning and executing the replacement of the existing MV switchgear and LV switchboards. The new design had to conform with the existing space and openings in the slab, as well as with existing exhaust ducts. As the NBS needed to be live at all times during the working week, all measurements had to be done without switching off the power supply. All the measurements in the substation for designing and purchasing purposes have been done under the voltage presence, without switching off the power supply.
Work was only allowed during the weekend since the NBS data center supports all the banking and financial transactions within Serbia. In the first two weekends, it was only permitted to work from Saturday morning to Sunday afternoon. Sunday evening, the NBS data center and entire office building must be in operation. After the first two weekends, our government published a state of emergency because of the COVID19 pandemic which limited working hours to Saturday from 7 a.m. up to 7 p.m. In spite of this, Log Design successfully replaced the switchboards for transformers T5 and T6 and DG set switchboard within less than 12 hours, as well as MV switchgear.
Live during inspection and installation
This project rendered the system integrator with multiple challenges in terms of keeping the original switchgear live during the entirety of the project -from scoping and inspection to final installation. A preeminent part of this project was that the National Bank of Serbia should be able to support banking and financial transactions while the 30-year-old switchgear was replaced. Additionally, the new switchgear had to fit into the same space as the old switchgear so the measurements had to be right on spot. Due to the modularity and many options for withdrawal units, Logstrup was able to supply low voltage switchgear that made this possible. The flexibility that the Logstrup Modular System offers, combined with the eminent engineering work from our global partner, resulted in switchgear that ensures a reliable power grid and power distribution so the National Bank of Serbia can keep on supporting their clients all around Serbia. Under these circumstances, Log Design supplied: • MV switchgear (11 panels) • LV switchboard for transformers T1 and T2 (In=2000A, 9 panels, 3 ACBs, 24 drawer units 160-400 amps) • LV switchboard for transformers T3 and T4 (In=2000A, 9 panels, 4 ACBs, 24 drawer units 160-400 amps) • LV switchboard for transformers T5 and T6 (In=2000A, 9 panels, 4 ACBs, 24 drawer units 160-400 amps) • LV switchboard for DG sets G1 and G2 (In=1000A, 7 panels, 3 ACBs, 31 drawer units 160-400 amps) • LV switchboard for safety and fire fighting systems (In=800A, 1 panel, 3 ACBs, 6 drawer units 160-400 amps) All ACBs are withdrawable and all drawers are WDU-A type. Additionally, all ACBs and MCCBs are advanced ABB breakers with Modbus communication and metering functions and we have designed and provided SCADA system for remote surveillance and control of transformer substation.
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