2500kva TNB Compact Substation for Malaysia

Project Location: Malaysia

Equipment Type: TNB Compact Substation (CSS) / Prefabricated Substation

Capacity: 2500 kVA

Voltage Rating: 11 kV / 0.415 kV (11,000V to 415V/240V, 50Hz)

Standards Compliance: TNB Technical Specifications, MS IEC 62271-200, IEC 60076

Project Background

With the rapid expansion of manufacturing and logistics hubs in Malaysia, a major industrial park developer required a high-capacity, reliable power distribution solution to support heavily loaded factory operations.

The project presented tight physical space limitations and a aggressive commissioning schedule. Furthermore, the local power grid, managed by Tenaga Nasional Berhad (TNB), mandates strict compliance regarding equipment safety, transformer loss parameters, switchgear protections, and grid interconnection interfaces.

To meet these requirements without undergoing lengthy, space-consuming civil substation building construction, the EPC contractor turned to TSTY for a customized 2500 kVA TNB Compact Substation (CSS) turnkey solution.

Engineering & Customization Highlights

1. Standardized Voltage & Grid Integration

The unit was configured precisely to meet the Malaysian medium-voltage distribution standard:

Primary Voltage (HV Side): 11 kV (50 Hz), fed via a high-reliability Ring Main Unit (RMU) featuring SF6/Clean Air insulation, motorized switches, and standard TNB-compatible cable termination compartments.

Secondary Voltage (LV Side): 415 V (3-Phase 4-Wire System) / 240 V (Single-Phase), fitted with air circuit breakers (ACB) and molded case circuit breakers (MCCB) configured for multi-feeder distribution to downstream factory sub-panels.

Transformer Core: 2500 kVA oil-immersed / dry-type transformer with low-loss core steel, custom-built to match TNB’s efficiency and impedance benchmarks.

2. Tropical Climate Resistance (IP54 Enclosure)

To ensure long-term operation in coastal areas without corrosion or insulation deterioration, tsty employs heavy-duty outdoor structural protection:

1.5mm Seamless One-Piece Enclosure: Manufactured with high-precision cold-press molds, eliminating original weld seams, ensuring uniform stress distribution, and completely preventing structural cracking and water/dust ingress.

C3–C5 Double-Layer Powder Coating: Implements a five-step protection process, including 220–250μm sandblasting and double-layer powder coating, with over 20,000 hours of salt spray testing, providing a lifespan three times that of standard painted enclosures.

IP54/IP65 Multi-Sealing Structure: Internally sealed doors, double-T interlocking door frames (with 4 transverse reinforcing ribs), and continuous EPDM sealing gaskets effectively isolate monsoon rainstorms and high humidity from the outside.

100% Stainless Steel Hardware: Stainless steel hinge pins (for 180° full opening of the enclosure lid) and stainless steel external bolts completely eliminate the risk of rust and jamming during long-term maintenance.

3. Space-Saving Modular Enclosure

Integrating HV Switchgear, a 2500 kVA Transformer, and LV Distribution Panels into a single factory-tested enclosure reduced the physical footprint by over 45% compared to a traditional brick-and-mortar substation.

4. Low Loss and Maximum Heat Dissipation

The continuous full-load operation of a 2500 kVA transformer in Malaysia during the summer demands exceptional thermal management and material integrity:

100% Pure Copper Windings: Zero aluminum wire and zero copper-clad aluminum, resulting in excellent conductivity, low internal resistance, and outstanding thermal stability under heavy-load motor starting shocks.

Optimized Cooling Oil Paths (2.5cm Spacing): The oil path spacing has been reduced from 5cm to 2.5cm, resulting in denser oil circulation and more uniform heat distribution. According to the Monsinger Law, insulation life doubles for every 6–8°C decrease in operating temperature.

Active Cabin Ventilation: The transformer compartment is equipped with axial flow fans, increasing ventilation by 30% to ensure continuous operation without overheating and tripping during afternoon high-temperature peaks.

5-Lead Safety Upgrade: The number of high-voltage leads has been increased from 3 to 5, significantly improving short-circuit withstand capability and overload safety margin.

High-Quality New Silicon Steel Sheets: The core laminations are stored in an RGV automated warehouse to prevent mechanical impact, maintaining low iron loss and low operating noise.

Key Technical Specifications

Project Execution & Impact

Factory Acceptance Testing (FAT): Prior to shipment, the 2500 kVA compact substation underwent full routine and type-testing compliance checks to ensure smooth inspection by local Malaysian electrical engineers.

Rapid On-Site Installation: Arriving as a fully pre-wired, self-contained unit, on-site work was limited to civil foundation placement and cable jointing. Installation time was reduced from weeks to 3 days.

Successful TNB Grid Energization: The substation successfully passed local utility inspection and was connected to the TNB 11kV distribution grid, delivering stable 415V power to the industrial facilities on schedule.