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 within a guaranteed 36-week worst case. 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. When the order needs new UL (cULus) or CSA certification, delivery is guaranteed within 36 weeks — against the one-to-four-year lead times common in the merchant market.
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