Power Equipment
Pad-mounted transformer sizes: 75 to 2500 kVA
Entogo builds three-phase pad-mounted distribution transformers in every standard rating from 75 to 2500 kVA: liquid-filled, dead-front units for 12.47 / 13.2 / 13.8 kV (15 kV class), 24.94 kV (25 kV class) and 34.5 kV (35 kV class) primaries stepping down to 208Y/120, 480Y/277 or 600Y/347 V at 60 Hz, designed and built to IEEE C57.12.34 / C57.12.28 and DOE 10 CFR 431 in Entogo's own factory. Engineered-to-order units ship in 16–24 weeks; UL (cULus) / CSA certification is available on request, and an order that needs new cULus/CSA certification ships within 36 weeks. Pick a rating below for its full-load and fault currents.
Full-load current by rating
Three-phase line current at rated load: amperes = kVA × 1000 ÷ (√3 × V). Primary currents assume the nominal system voltage; secondary currents are at the secondary line-to-line voltage.
| Rating | 208Y/120 V secondary | 480Y/277 V secondary | 600Y/347 V secondary | 12.47 kV primary | 13.8 kV primary | 24.94 kV primary | 34.5 kV primary |
|---|---|---|---|---|---|---|---|
| 75 kVA | 208 A | 90.2 A | 72.2 A | 3.5 A | 3.1 A | 1.7 A | 1.3 A |
| 112.5 kVA | 312 A | 135 A | 108 A | 5.2 A | 4.7 A | 2.6 A | 1.9 A |
| 150 kVA | 416 A | 180 A | 144 A | 6.9 A | 6.3 A | 3.5 A | 2.5 A |
| 225 kVA | 625 A | 271 A | 217 A | 10.4 A | 9.4 A | 5.2 A | 3.8 A |
| 300 kVA | 833 A | 361 A | 289 A | 13.9 A | 12.6 A | 6.9 A | 5.0 A |
| 500 kVA | 1,388 A | 601 A | 481 A | 23.1 A | 20.9 A | 11.6 A | 8.4 A |
| 750 kVA | 2,082 A | 902 A | 722 A | 34.7 A | 31.4 A | 17.4 A | 12.6 A |
| 1000 kVA | 2,776 A | 1,203 A | 962 A | 46.3 A | 41.8 A | 23.1 A | 16.7 A |
| 1500 kVA | 4,164 A | 1,804 A | 1,443 A | 69.4 A | 62.8 A | 34.7 A | 25.1 A |
| 2000 kVA | 5,551 A | 2,406 A | 1,925 A | 92.6 A | 83.7 A | 46.3 A | 33.5 A |
| 2500 kVA | 6,939 A | 3,007 A | 2,406 A | 116 A | 105 A | 57.9 A | 41.8 A |
Every rating links to its own page with fault-current tables, ratings at a glance and typical applications. The catalogue page for the product family is the Three-Phase Pad-Mounted Distribution Transformer.
Construction common to every rating
What is fixed across the range, and what is specified per project.
- Designed and built to IEEE C57.12.34 (three-phase pad-mounted) and C57.12.28 (enclosure integrity), tested per C57.12.90, CSA C88; 60 Hz.
- Primary 12.47 / 13.2 / 13.8 kV (15 kV class, 95 kV BIL), 24.94 kV (25 kV class, 125 kV BIL) or 34.5 kV (35 kV class, 150 kV BIL); secondary 208Y/120, 480Y/277, 240/120 or 600 V.
- Liquid-filled, ONAN, 65 °C average winding rise; mineral oil standard, FR3 natural ester optional; copper or aluminium windings.
- Dead-front, 200 A loadbreak bushing wells; loop-feed (6 bushings) or radial-feed (3 bushings); live-front on request.
- De-energized tap changer, ±2 × 2.5 % standard.
- Core-and-coil designed to DOE 10 CFR 431 minimum efficiency; amorphous-metal core optional for loss-evaluated bids.
- Tamper-resistant NEMA 3R cabinet, ANSI 70 green powder coat, pad-lockable.
- UL (cULus) / CSA certification available on request; minimum 36-month manufacturer warranty, extended terms on major power equipment per contract.
FAQ
Common questions
- What sizes do three-phase pad-mounted transformers come in?
- The standard three-phase ladder is 75, 112.5, 150, 225, 300, 500, 750, 1000, 1500, 2000 and 2500 kVA (IEEE C57.12.00), and Entogo builds pad-mounted units in every one of those ratings, with 3000 kVA available on request.
- How do I calculate the full-load current of a pad-mounted transformer?
- Full-load current in amperes = kVA × 1000 ÷ (√3 × line-to-line volts). A 500 kVA unit delivers about 601 A at 480 V, 1,388 A at 208 V and 481 A at 600 V; on a 12.47 kV primary it draws about 23 A. The table on this page lists every rating.
- Which primary and secondary voltages are available?
- Primaries: 12.47, 13.2 and 13.8 kV (15 kV class, 95 kV BIL), 24.94 kV (25 kV class, 125 kV BIL) and 34.5 kV (35 kV class, 150 kV BIL). Secondaries: 208Y/120, 480Y/277, 240/120 and 600 V. Every unit is 60 Hz; other combinations are built to order.
- How long does an Entogo pad-mounted transformer take to deliver?
- Pad-mounted transformers are engineered to order and ship from Entogo's own factory in 16–24 weeks — against the one-to-four-year lead times common in the merchant market. When the order needs new cULus/CSA certification, delivery is within 36 weeks.
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