800 kVA Oil-Immersed Distribution Transformer

800 kVA Oil-Immersed Distribution Transformer is specified for 800 kVA oil-immersed distribution service. It uses ONAN cooling. Engineering details address scaling Up Maintenance-Free Power, construction, application context, and electrical data for project selection.

Scaling Up Maintenance-Free Power

For this 800 kVA rating, scaling up maintenance-free power affects how the transformer is selected, protected, and operated in the field.

• It 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 rating 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.

Structural Integrity & Tank Engineering

The structural integrity and tank engineering details below highlight design choices that matter during continuous distribution service.

• At 800 kVA, the physical forces exerted on the tank walls during full-load operation are substantial.
• Reinforced Corrugation: To maintain the seal, the design uses 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.

Efficiency and Sound Control

These efficiency and sound control points connect the electrical rating with grid conditions, downstream equipment, and maintenance expectations.

• As transformers grow in size, noise and losses become more pronounced.
• Low-Loss Core: the design uses 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.

Active Protection Systems

These active protection systems points connect the electrical rating with grid conditions, downstream equipment, and maintenance expectations.

• Given the capital value of an 800 kVA asset, we equip it with integrated safety devices: 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.
• HV Bushings: Upgraded to porcelain or composite resin with extended creepage distances for polluted industrial environments.

Typical Installation Contexts

Application guidance links the transformer rating with the substations, industrial loads, and site conditions where it is normally used.

• Large Commercial Facilities: Serves as the main incomer for shopping malls or large office blocks, where the load profile includes central HVAC chillers.
• 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.

Electrical and Mechanical Data

The electrical data summarizes the main values needed for project comparison and project comparison.

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