How Low Is the Partial Discharge Level in a 750 kVA Three Phase Dry Type Cast Resin Power Transformer with Vacuum Casting Technology

For engineers and procurement specialists, the partial discharge (PD) level is a non‑negotiable quality indicator in a 750 kVA Three Phase Dry Type Cast Resin Power Transformer. LUGAO manufactures these units using advanced vacuum casting technology, routinely achieving PD levels below 10 picocoulombs (pC) – significantly lower than the industry standard of 20‑50 pC for conventional cast resin designs.

Why Vacuum Casting Dramatically Lowers PD

Traditional casting traps micro‑air voids inside the resin. Under high voltage, these voids ionize and create partial discharges. LUGAO’s vacuum casting process removes air before curing, eliminating internal cavities. The result is a 750 kVA Three Phase Dry Type Cast Resin Power Transformer with exceptional dielectric strength and operational reliability.

Benefits of Ultra‑Low Partial Discharge

• Prevents progressive insulation degradation – PD as low as 50 pC will erode resin over time. At <10 pC, erosion is negligible.

• Reduces unplanned downtime – Fewer field failures mean lower maintenance costs.

• Meets strict IEC 60076‑11 standards – LUGAO units exceed the required PD limits for high‑reliability applications (hospitals, data centers, industrial plants).

750 kVA Three Phase Dry Type Cast Resin Power Transformer – FAQ

Q1: What is the maximum acceptable partial discharge level for this transformer according to IEC standards?

A1: IEC 60076‑11 states that for cast resin transformers rated above 3 kV, the partial discharge level should not exceed 20 pC at 1.3 times the phase‑to‑earth voltage during routine tests. LUGAO‘s 750 kVA Three Phase Dry Type Cast Resin Power Transformer consistently measures below 10 pC, providing a 50% safety margin below the maximum allowed value. This ensures superior long‑term insulation health even under voltage surges or harmonic‑rich loads.

Q2: How does temperature and humidity affect partial discharge levels in service?

A2: Partial discharge levels can rise with increased temperature or moisture absorption. In standard cast resin designs, humidity above 80% may temporarily raise PD by 5‑10 pC. LUGAO uses hydrophobic epoxy resins and post‑curing cycles that keep PD below 15 pC even at 90% relative humidity and 120°C winding temperature. This stability makes the 750 kVA Three Phase Dry Type Cast Resin Power Transformer ideal for tropical climates or unventilated electrical rooms.

Q3: How can I verify the PD level of a transformer before purchase?

A3: Request the factory routine test report according to IEC 60076‑11. A reliable manufacturer will perform PD measurements using a calibrated detection system at 1.3 x rated voltage. LUGAO provides for every 750 kVA Three Phase Dry Type Cast Resin Power Transformer a certified test protocol showing actual PD levels, applied test voltage, and background noise levels. You may also request witnessed testing at LUGAO’s facility before shipment.

Take the Next Step

Choosing a transformer with proven low partial discharge means choosing decades of trouble‑free operation. Contact LUGAO today for a datasheet, a sample test report, or a quotation tailored to your voltage and vector group requirements. Our engineers are ready to support your project globally.