CRGO Silicon Steel Core
Constructed from high-permeability cold-rolled grain-oriented (CRGO) silicon steel sheet imported from France and Japan. Stepped core assembly minimizes no-load losses, excitation currents, and acoustic humming.
Substation Equipment
Distribution Transformers
Heavy-duty oil-immersed distribution transformers engineered for high electrical efficiency, minimum operational losses, and exceptional lifespan under tropical operating conditions.
Made to project specification
Verified Operating Ratings
- primary Voltage
- 11 kV
- secondary Voltage
- 415 / 220 V
- frequency
- 50 Hz
- phase
- 3 Phase
- cooling Systems
- ONAN (Oil Natural Air Natural) / ONAF (Oil Natural Air Forced)
- insulation Class
- Class A
- design Standards
- IEC 76, BS 171, ANSI C57.12, VDE 0532
Engineering & Manufacturing Architecture
Electrolytic Copper Windings
Manufactured using high-conductivity electrolytic copper with pinhole-free super enameled wire for HV windings and pure cellulose paper insulated copper strips for LV windings.
Seam-Welded Radiators & Heavy Tank
Fabricated from high-grade sheet steel with a rigid bottom and oil drainage outlet. Radiators are formed in-house with seam, MIG, and TIG welding, chemically degreased, and pressure tested for zero leakage.
Corrosion-Resistant Multi-Coat Finish
Tanks are sandblasted to international standards before applying a zinc-etching primer and two heavy protective coats, achieving a minimum thickness of 140 microns.
Precision Tap Changer
Fitted with off-circuit tap changers from Come (Italy) built with high-grade igneous insulating board or synthetic resin mould, allowing precise voltage adjustment.
Accredited In-House Routine Testing
Every unit is tested in our BSTI and BUET approved laboratory for insulation resistance, turns ratio, induced overvoltage, load and no-load losses, and oil breakdown voltage.
Standard & Optional Protection Accessories
Buchholz Relay
Installed between tank and conservator to detect internal electrical faults and gas build-up, with micro-switch contacts rated at 5A 250VAC.
DGPT2 Hermetic Relay
Ideal for hermetically sealed designs to monitor gas discharge, temperature, and internal pressure surges in transformers >500 kVA.
Pressure Relief Valve
Spring-loaded valve that opens briefly during internal pressure surges and automatically reseals to protect tank integrity.
Silica Gel Breather
Unidirectional dehydrating breather with liquid silicon oil seal preventing moisture ingress into the insulating oil.
Magnetic Oil Level Indicator
Dual permanent magnet transmission displaying oil levels in the conservator without risk of oil leaks.
Dial Thermometer with Contacts
Max-pointer temperature gauge scaled up to 120°C with adjustable alarm and trip electrical contacts.
BSTI & BUET Approved Testing Protocol
Final tests executed strictly in accordance with IEC 76 on completely assembled transformers in our accredited facility.
Routine Tests (100% Units)
- ✓ Insulation Resistance Test
- ✓ Induced Over-Voltage Test
- ✓ Separate Source Voltage Withstand Test (HV & LV)
- ✓ Turns Ratio, Polarity & Phase Relationship Test
- ✓ HV & LV Winding Resistance Test
- ✓ No-Load Current & No-Load Loss Measurement
- ✓ Full-Load Current & Full-Load Loss Test
- ✓ Load Loss at Rated Current & Frequency
- ✓ Percentage Impedance Verification
- ✓ Core Insulation Test
- ✓ Insulating Oil Dielectric Strength & Tan-Delta Test
- ✓ Tap Changer Functional Test
Type Tests (Per Production Lot)
- • Temperature Rise Test
- • Short-Circuit & Overload Withstand Test
- • Acoustic Noise Level Test
- • Oil Leakage Pressure Test
Engineering Specification Matrix
Distribution Transformers Specifications
Scroll horizontally →
| Capacity (kVA) | No-Load Loss (W) | Full-Load Loss (W) | Impedance (% Imp) | Regulation (% at UPF) | Efficiency (% at UPF) | Height H (cm) | Length L (cm) | Width W (cm) | Oil (Liters) | Weight (kg) |
|---|---|---|---|---|---|---|---|---|---|---|
| 100 | 245 | 1700 | 4.0 | 1.62 | 98.05 | 132 | 100 | 63 | 180 | 650 |
| 150 | 320 | 2412 | 4.0 | 1.40 | 98.17 | 145 | 105 | 88 | 220 | 900 |
| 200 | 435 | 2550 | 4.0 | 1.20 | 98.37 | 150 | 112 | 93 | 230 | 975 |
| 250 | 520 | 3265 | 4.0 | 1.22 | 98.48 | 158 | 123 | 95 | 270 | 1100 |
| 315 | 580 | 4500 | 4.0 | 1.15 | 98.38 | 157 | 120 | 97 | 350 | 1250 |
| 400 | 722 | 5420 | 5.0 | 1.10 | 98.44 | 162 | 123 | 98 | 390 | 1450 |
| 500 | 865 | 6275 | 5.5 | 1.05 | 98.57 | 165 | 124 | 102 | 325 | 1725 |
| 630 | 920 | 7740 | 6.0 | 0.98 | 98.62 | 170 | 136 | 103 | 500 | 1970 |
| 750 | 1150 | 8850 | 6.0 | 0.94 | 98.66 | 185 | 155 | 112 | 625 | 2250 |
| 800 | 1300 | 9800 | 6.0 | 0.90 | 98.61 | 225 | 170 | 113 | 650 | 2575 |
| 1000 | 1650 | 11600 | 6.5 | 0.99 | 98.67 | 215 | 185 | 115 | 800 | 2850 |
| 1250 | 1820 | 12300 | 6.5 | 0.95 | 98.87 | 225 | 190 | 116 | 1000 | 3725 |
| 1500 | 2100 | 13275 | 6.5 | 0.87 | 98.97 | 230 | 200 | 120 | 1200 | 4300 |
| 2000 | 2650 | 16470 | 6.5 | 0.83 | 98.04 | 250 | 210 | 135 | 1450 | 4750 |
| 2500 | 3140 | 19700 | 7.0 | 0.82 | 99.08 | 285 | 220 | 150 | 1800 | 5600 |
| 3000 | 4500 | 24500 | 7.0 | 0.82 | 99.08 | 290 | 230 | 160 | 2000 | 6000 |
* All dimensions include conservator tank. Dimensions and weights are subject to ±5% variation in line with ongoing engineering improvements.
Assembly & Hardware Details
Engineering Publication • 20-Page Comprehensive Edition
Download the Complete Pacific Powertech Technical Catalog
Access complete engineering schematics, power transformer loss tables, switchgear dimensions, and automation panel specifications in our official 20-page reference catalog.
