800 Kva Oil-filled Transformer

The 800 kVA Oil Immersed Transformer acts as a critical substation node for large-scale infrastructure, effectively bridging the gap between medium voltage distribution and low voltage consumption. While smaller units are common, achieving a truly maintenance-free lifespan at this capacity requires advanced engineering.

We manufacture this unit as a premium oil immersed hermetically sealed type transformer. Unlike traditional designs that rely on a breathing conservator, this model completely isolates the 600+ liters of insulating oil from the atmosphere. This is achieved not just by sealing, but by engineering a tank capable of handling significant internal pressure variations caused by the thermal expansion of such a large volume of oil.

At 800 kVA, the physical forces exerted on the tank walls during full-load operation are substantial.

• Reinforced Corrugation: To maintain the seal, we use extra-deep corrugated fins made from heavy-gauge steel. These act as dynamic expansion joints, absorbing the oil volume changes (approx. 10% volumetric change from cold to hot) without fatiguing the steel seams.
• Nitrogen Cushion Option: For specific high-variation climates, we can include a nitrogen gas cushion under the cover of this oil immersed hermetically sealed type transformer. This compressible gas layer absorbs pressure spikes, ensuring the internal pressure remains within the safe operating limits of the gaskets (typically <0.35 bar).

As transformers grow in size, noise and losses become more pronounced.

• Low-Loss Core: We utilize laser-scribed Silicon Steel sheets to manage eddy current losses. This ensures that the no-load loss conforms to the strict Eco-design Tier 2 regulations, keeping standby energy costs low.
• Sound Dampening: To counter the magnetostriction hum typical of an 800 kVA unit, the core is clamped with non-magnetic steel frames and rests on anti-vibration pads inside the tank, keeping noise levels typically below 58-60 dB.

Given the capital value of an 800 kVA asset, we equip it with integrated safety devices:

1. DGPT2 (Detection of Gas, Pressure, and Temperature): A compact protection block often installed on sealed units to monitor gas accumulation, internal pressure, and oil temperature simultaneously.
2. HV Bushings: Upgraded to porcelain or composite resin with extended creepage distances for polluted industrial environments.

• Large Commercial Facilities: Serves as the main incomer for shopping malls or large office blocks, where the load profile includes central HVAC chillers.
• Industrial Feeder: Installed in indoor or outdoor substations to power a specific factory section, capable of sustaining continuous loads of approx. 1150 Amps.
• Renewable Energy: Used as a step-up unit for 0.8 MW solar inverter stations.

800 kVA oil immersed transformer powering a large commercial

shopping mall complex.