1 Classes 7200, 7300, 7400. MARCH, 1995. Medium Voltage Transformers Specification Guide Medium Voltage Transformers Table of Contents PAD-MOUNTED SUBSTATION. Page 5 Page 13. PAD-MOUNTED .. 5 PAD-MOUNTED transformers, SUBSTATION liquid-filled transformers Description .. 5 liquid-filled and dry-type, are best are ideal for use in light to medium Applicable Standards .. 5 suited for commercial applications industrial applications. Specifications Pad-mounted in public access areas and where Liquid-Filled Transformers .. 6 underground service is required. Design Life Specifications VPI Pad-mounted Dry-Type Transformers .. 8 20 years* standard rectangular Design Life Liquid-Filled Application.
2 10 construction optimizes the dielectric 20 years* compact, low profile value of the insulating fluid. design and rectangular construction provide years of service. LIQUID-FILLED, SUBSTATION .. 13 Environmental Information Description .. 13. Environmental Information Sealed tank construction Applicable Standards .. 13. Sealed tank construction on fluid-filled Suitable for some poor environments Specifications .. 14. Application .. 16 units Special waste disposal considerations Special waste disposal considerations for fluid-filled units for fluid-filled units POWER-DRY .. 21 Ratings Description .. 21. Ratings 225 10,000 kVA (fan cooling allows Applicable Standards.)
3 21 higher kVA ratings). 75 5,000 kVA. Specifications .. 22. to 46 kV primary to 46 kV primary Application .. 24. 120 C insulation temperature limit 120 C insulation temperature limit UNI-CAST .. 27 Cost of Ownership Cost of Ownership Description .. 27 Low initial costs Low initial costs Applicable Standards .. 27. Some cost associated with Some cost associated with Specifications .. 28 maintenance to ensure proper maintenance to ensure proper Application .. 30 fluid levels on liquid-filled units fluid levels Virtually no maintenance on dry-type units POWER-CAST .. 33. Description .. 33. Applicable Standards .. 33. Specifications Cast Coil Substation Transformer .. 34.
4 Application .. 36. * Design life is a function of operating conditions and maintenance. This does not constitute any expressed or implied warranty. 2. POWER-DRY UNI-CAST POWER-CAST . Page 21 Page 27 Page 33. POWER-DRY dry-type transformers UNI-CAST transformers combine POWER-CAST transformers provide meet requirements for commercial the best of cast-coil construction with the rugged durability needed for harsh applications such as multiple-floor power-dry Engineering . UNI-CAST environments where chemical fumes, buildings and rooftop installations. transformers are best suited for light dust, or vibration may be present in to medium industries such as food industries such as automotive, shipping, and beverage, high-technology, and rapid transit.
5 Design Life pharmaceuticals, and pulp and paper. 20 years* compact, barrel-wound rectangular construction for long Design Life service life. Circular windings Design Life 40 years* cast-coil construction provide higher BIL ratings. 30 years* cast-coil primary winding coupled with standard copper construction provides long-lasting windings provides long-lasting durability. Circular windings infused durability. Cast primary and Environmental Information with epoxy improve short circuit secondary windings are designed Intended for relatively clean strength. with superior mechanical environments reinforcement throughout the full No fluids translates to low fire risks length of the coils.
6 Environmental Information No special waste disposal Intended for relatively clean considerations Environmental Information environments, but can be used in Excellent replacement for PCB-filled some harsher environments Intended for the harshest and gas-filled transformers environments where long-term No fluids translates to low fire risks dependability is a must. No special waste disposal Ratings considerations No fluids translates to low fire risks 67 1333 kVA single-phase Excellent replacement for PCB-filled No special waste disposal transformers considerations 225 5000 kVA three-phase (fan cooling allows higher kVA ratings). Excellent replacement for PCB-filled transformers to 25 kV primary Ratings 220 C insulation temperature limit 500 3,000 kVA (fan cooling allows higher kVA ratings) Ratings to 35 kV primary 500 10,000 kVA (fan cooling allows Cost of Ownership 185 C insulation temperature limit higher kVA ratings).
7 Low initial costs to 46 kV primary Virtually no maintenance 185 C insulation temperature limit Cost of Ownership Moderate cost when long life expectancy is considered Cost of Ownership Virtually no maintenance Investment in reliability lowers the overall cost over its long life span Virtually no maintenance * Design life is a function of operating conditions and maintenance. This does not constitute any expressed or implied warranty. 3. Notice Words and figures in brackets are alternatives; select only one. Metric Conversion Inches (in) x = millimeters (mm). Factors Square inches (sq in; in2) x = square millimeters (mm2). Cubic inches (cu in; in 3) x = cubic centimeters (cc; cm 3).
8 Feet (ft) x = meters (m). Pound inches (lb in) x = Newton meters (N m). Pounds per square inch (psi) x = atmospheres (atm). 4. Pad-Mounted Transformers FPO. Description Three-phase, pad-mounted transformers, for use on underground power distribution systems, meet modern design requirements for flexibility, and provide a visually pleasing installation. Construction allows installation in locations accessible to the general public without the need for protective fencing or vaults. These units are ideally suited for apartment buildings, schools, hospitals, shopping centers, commercial buildings, or industrial sites. Standard liquid-filled sizes range from 75 5,000 kVA with primary ratings from 2,400V to 46,000V.
9 For dry-type units, standard sizes range from 225 750 kVA with primary rating from 2,400V to 15,000V. These designs meet all applicable industry standards of ANSI, NEMA, CSA, and IEEE. Applicable A. ANSI Specifications for Distribution Fuse Disconnecting Switches, Fuse Supports, Standards and Current-Limiting Fuses. B. IEEE Standard General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers (ANSI). C. IEEE Standard General Requirements for Dry-Type Distribution and Power Transformers. D. ANSI Requirements for Pad-Mounted, Compartmental-Type, Self-Cooled, Three-Phase Distribution Transformers with High Voltage Bushings; 2,500 kVA and Smaller: High Voltage, 34,500 GrdY/19,920 Volts and Below; Low Voltage, 480 Volts and Below Requirements.
10 E. ANSI Standard for Transformers Pad-Mounted, Compartmental-Type, Self-Cooled, Three-Phase Distribution Transformers for use with Separable Insulated High Voltage Connectors: High Voltage, 34,500 GrdY/19,920 Volts and Below; 2,500 kVA and Smaller. F. ANSI Switchgear and Transformers, Pad-Mounted Equipment Enclosure Integrity. G. ANSI Requirements for Ventilated Dry-Type Distribution Transformers, 1 500 kVA Single-Phase and 15 500 kVA Three-Phase, with High Voltage 601 34,500 Volts, Low Voltage 120 600 Volts. H. IEEE Requirements for Ventilated Dry-Type Power Transformers, 501 kVA. and Larger Three-Phase, with High Voltage 601 34,500 Volts, Low Voltage 208Y/120 . 4,160 Volts.