250 Kva Oil-filled Transformer

The 250 kVA Oil Immersed Transformer represents a critical threshold in power distribution, often serving as the dedicated power source for standalone facilities or facility wings. Unlike smaller pole-mounted units, this transformer is engineered to manage substantial continuous currents (approx. 360A at 400V) with superior thermal stability.

One of the distinct advantages of this oil immersed transformer over dry-type alternatives is its high thermal inertia. The specific heat capacity of the mineral oil allows the unit to absorb and dissipate heat generated during temporary overload spikes-common in industrial motor startups-without triggering immediate temperature alarms.

At the 250 kVA capacity level, mechanical strength becomes paramount. We utilize LV Foil Winding Technology for the low-voltage coils, a significant upgrade from the wire-wound technique used in smaller transformers.

• Zero Axial Forces: By winding the full width of the coil with copper or aluminum foil, we effectively balance the ampere-turns. This means that during a short-circuit event, the axial forces (which can tear a transformer apart) are virtually eliminated.
• Cooling Efficiency: The foil structure eliminates internal air gaps found in wire windings. This maximizes the contact area between the conductor and the insulation paper, improving heat transfer to the surrounding oil in this immersed transformer design.

To ensure longevity, the tank is equipped with essential monitoring devices. A dial-type oil thermometer allows operators to visualize the top-oil temperature directly. For enhanced safety, we integrate a pressure relief valve that activates if internal pressure exceeds safe limits (typically 0.30 - 0.35 bar) due to a fault, preventing tank rupture.

Pressure relief valve installed on 250 kVA oil transformer for

explosion protection.

The 250 kVA unit is the "workhorse" size for specific facility feeds:
1. Schools and Hospitals: Providing reliable power for lighting, HVAC, and sensitive medical equipment.
2. Small Factories: Ideal for powering a specific production line with multiple motors.
3. Shopping Centers: Dedicated supply for refrigeration units and escalator systems.

250 kVA oil immersed transformer providing reliable power

supply for commercial buildings and schools.