75kVA Three Phase Pad Mounted Transformer

Technical Specifications

75kVA Three Phase Pad Mounted Transformer

Technical Specifications

Accessories

Customization Optional

75kVA Three Phase Pad Mounted Transformer

Zisheng transformers offer pad mounted transformer a wide range of optional features to meet the diverse needs of electrical systems. The optional specifications for a 75kVA Three Phase Pad Mounted Transformer may include various customizable features to meet specific operational needs. These options typically involve different voltage ratings (both high and low voltage), various enclosure protection levels (such as IP55 or NEMA 3R), and cooling methods (like ONAN for optimal temperature rise management). Safety upgrades like bayonet fuses, expulsion fuses, lightning arresters, or wildlife protection address specific risks, while fluid options extend to natural ester for elevated fire safety and environmental benefits. These personalized choices enhance efficiency, surge protection, and installation flexibility, providing utilities with a dependable transformer optimized for underground three-phase power delivery.

Additional options may include customizable load connection types (Delta-Delta, Wye-Wye, Delta-Wye), advanced protection devices (overload and short-circuit protection), and smart monitoring systems for real-time performance tracking. Furthermore, customers may select enhanced durability options, corrosion-resistant coatings for harsh environments, and reduced noise designs. These specifications allow the transformer to be tailored to specific applications and environmental conditions, ensuring reliable and efficient operation. These broad customizations establish the 75kVA three phase pad mounted transformer as a versatile, high-performance option, ensuring regulatory adherence, reduced lifecycle expenses, and superior reliability in pad-mounted underground networks for commercial, retail, and light industrial uses.

Packing and Shipping

75kVA Three Phase Pad Mounted Transformer

Zisheng three-phase transformers are designed to be securely packaged for sea freight transport, ensuring safe delivery across long distances. For this purpose, the 75kVA Three Phase Pad Mounted Transformer is typically packed and shipped to ensure its protection during transportation and to comply with international shipping standards. The transformer is securely placed on a sturdy wooden pallet or skid to prevent any movement during transit. It is then wrapped with weather-resistant plastic or shrink wrap to protect it from moisture, dust, and other environmental factors. For additional safety, the transformer may be enclosed in a wooden crate or reinforced container, especially for long-distance or international shipments.
Shipping is usually done via flatbed trucks or containers, depending on the destination and transport logistics. The packaging is designed to protect the transformer from mechanical damage, such as impacts or vibrations, while maintaining its integrity. All relevant shipping labels, including the weight, dimensions, and handling instructions, are clearly marked on the packaging to ensure smooth handling upon arrival. If shipping internationally, customs documentation and export packaging requirements will also be addressed to facilitate hassle-free clearance.
Sustainability guides packing selections, favoring responsibly sourced, recyclable wood and consolidated loading to lower carbon emissions. Attached impact and tilt recorders log transit conditions, supporting arrival verifications and efficient claim resolution. Optional accessories such as arresters, fuses, or gauges are crated separately with detailed inventories for onsite reconciliation. Proven carriers specializing in pad-mounted gear obtain required permits and follow rigorous safety measures across land and sea routes.
Post-delivery assistance includes pad foundation recommendations, detailed unpacking protocols, fluid refill guidelines, and connection torque specifications. Coordination with local teams facilitates safe installation and rapid energization. This thorough logistics process safeguards transformer quality, accelerates commissioning, and enables seamless deployment in underground three-phase commercial power infrastructures.

Manufacturer Test

75kVA Three Phase Pad Mounted Transformer

Progress test

Zisheng manufacture pad mounted transformer have the strict quality control from the raw material stage, Each 75 kVA transformer undergoes a series of routine tests before it leaves the factory, in strict adherence to the ANSI/IEEE C57.12.90 standard. These tests are critical to ensuring the transformer's performance and safety. The routine tests consist of the following:
Ratio tests on each connection.
(b) Polarity verification.
(c) Assessment of no-load losses at 105% rated voltage, corrected to 85°C.
(d) Evaluation of exciting current at 105% rated voltage.
(e) Measurement of load losses and impedance at rated current, conducted on the rated voltage connection, and corrected to 85°C. It's important to note that this test is performed on the high-voltage connection that exhibits the highest measured loss value.
(f) Applied voltage tests.

Design Tests

All transformers will be tested after finishing the production, test items as follows:
♦ Insulation Power Factor
♦ Ratio, Polarity, and Phase Relation
♦ Winding Resistance
♦ Impulse Tests
♦ On load Loss Test
♦ No Load Loss Test
♦ Leak Test
♦ DC Insulation Resistance Test
♦ Transformer Turns Ratio/TTR (All Tap Voltages)
♦ Impedance Voltage & Load Loss (Rated Voltage)
♦ Polarity, 1-Ph / Phase Relation, 3-Ph (Rated Voltage)
♦ Excitation & No-Load Loss (Rated Voltage)
♦ Temperature Rise
♦ Dielectric Withstand (Hipot)

Transformer Factory Acceptance Test

Advancing through FAT for the 75kVA three phase pad mounted transformer, lightning impulse withstand at 60-150kV BIL (voltage-dependent) applies full and chopped waves to affirm insulation robustness. Sound level testing in acoustic isolation meets regulatory thresholds. Temperature rise under equivalent load simulation restricts top-oil and winding increases to 65°C. Accessory functionality checks pressure relief operation, gauges, tap changer mechanics, and parking stands. Sweep frequency response analysis verifies core and winding mechanical condition. Comprehensive test compilation follows IEEE C57.12.90, ANSI C57.12.34, and DOE protocols with calibration traceability, client witnessing, and prompt discrepancy resolution prior to final acceptance and shipment readiness. Load loss and impedance derive accurately from short-circuit testing for performance validation. Power frequency withstand imposes specified kV for one minute without disruption. Induced voltage assessment stresses turn insulation. Fluid evaluation confirms breakdown voltage above 40kV and minimal gas content.

Routine Test - Applied Voltage

Purpose of Testing

The purpose of testing the applied voltage is to verify the insulation strength of the transformer by applying a voltage higher than its normal operating level, ensuring it can withstand potential electrical stresses. This test helps identify any weaknesses or defects in the insulation system before the transformer is put into service.

Testing Equipment

Test equipment: High voltage tester (e.g. TTR, Hipot, etc.)
Voltage source: usually 1 kV, 5 kV, 10 kV, or customized according to customer needs
Temperature and humidity meter: used to record environmental conditions

Pre-Test Preparation

Disconnect the device from the power supply and make sure it is properly grounded and discharged.
Check the connection terminals and wiring to ensure that they are not loose or contaminated.
Test under suitable environmental conditions: relative humidity below 75% and no rain (recommended temperature: 20-30°C).

Test Progress

Connect the Test Instrument:
Properly connect the test equipment to the bushings or terminals of the device under test and ensure that all connection points are properly grounded.
Selecting the test voltage:
Select the appropriate applied voltage based on the rated voltage of the equipment.

Measure and Record

Start the test and record the following parameters:
Measuring leakage current
Applied voltage
Current stability
Any possible voltage fluctuations

Temperature Correction

If necessary, the measured data is temperature corrected to ensure that it corresponds to standard temperature conditions (usually 20°C).

Repeat Testing (if necessary)

Multiple tests were conducted on different windings (high voltage, medium voltage, low voltage) and bushings, and comparative analysis was performed.

Evaluation Criteria (Reference)

The test was normal and the equipment performed well (qualified)
The current value exceeded the allowable range and the equipment needs to be inspected or maintained (pending repair)
There was a serious fault or instability and the equipment could not continue to operate (unqualified)

Observing electrical behavior

Observe the electrical behavior of the device under test to ensure that there are no abnormal currents, arcing, noise, or electrical faults.

*These comprehensive tests ensure that each transformer meets performance standards and operates reliably under various conditions.