ET3 / ET1 — dry-type LV power transformers up to 2 500 kVA, including water-cooled and with the APS pre-magnetizing system
Country: Poland · Model: ET3 / ET1
Dry-type low-voltage power transformers ET3 (three-phase, 40–2 500 kVA) and ET1 (single-phase, up to 100 kVA) for voltage up to 1 100 V. Cooling is natural, forced air or water, and the windings are copper or aluminium. They are installed on railways, in the oil and gas and heavy industries, in renewable energy and in power electronics circuits.
- Power
- ET3: 40–2 500 kVA; ET1: 0.05–100 kVA
- Voltage
- < 1 100 V
- Frequency
- 50/60 Hz (LV line: 16.7–1 000 Hz)
- Cooling
- AN; optional AF and WF (water)
Technical specifications
| Power | ET3: 40–2 500 kVA; ET1: 0.05–100 kVA |
|---|---|
| Voltage | < 1 100 V |
| Frequency | 50/60 Hz (LV line: 16.7–1 000 Hz) |
| Cooling | AN; optional AF and WF (water) |
| Insulation class | F or H |
| Windings | aluminium or copper |
| Protection rating | IP00, IP23, IP44, IP54, IP66; NEMA 3/3R, 4/4X |
| Climate | C1/E0 onshore; C2/E1 marine/mountain; F1 optional |
| Standards | PN-EN 60076-11, EN/IEC 60726; UL (component, up to 80 kVA) |
Replacement for
TSZI, TSZ 0.38/0.23 kV (dry low-voltage), OSM1-0.063…4 kVA (single-phase), OSO; TSZ 0.4/0.4 kV up to 2500 kVA — general type
selected by purpose and main parameters, please confirm with the manager
Replacement pages: ОСМ1-0,063, ОСМ1
Specifications are taken from the manufacturer’s technical documentation. Updated .
Description
The magnetic core is built of electrical steel, the windings are impregnated by the vacuum pressure impregnation (VPI) method, so the unit withstands higher temperature and humidity. The line covers frequencies from 16.7 to 1 000 Hz, and the factory has produced more than 370 000 LV units. The standard vector group is Dyn5, insulation class F or H. Each transformer has lifting eyes, mounting brackets and earthing clamps, and the number of taps and the position of the terminals are set by the customer. Protection ratings range from IP00 to IP66, also NEMA 3/3R and 4/4X. In the water-cooled version an insulated cooler lies inside the windings, which according to the manufacturer reduces the unit volume by up to 30 % and carries up to 95 % of heat losses into the water. The AF/WF version with a water–air heat exchanger makes the transformer up to 20 % lighter. The APS (Advanced Pre-Magnetizing System) option pre-magnetizes the core through resistors and removes the magnetizing inrush current, so in weak networks and on generator supply there are fewer voltage dips and false protection trips. Compliance with PN-EN 60076-11 and EN/IEC 60726. UL certifies three-phase transformers up to 80 kVA and insulation systems of classes 155 (F) and 180 (H) per UL 1446.
How to choose
First determine the number of phases and the power. The ET3 covers 40–2 500 kVA, the ET1 is used up to 100 kVA. Then choose the cooling. AN suits when there is space and ventilation, and AF or WF are needed where size and weight are critical. For outdoors or dust take an IP54–IP66 enclosure. For rectifiers there are separate transformers, for railway signalling circuits the ET3KOL and ET1KOL, for operating rooms the ET1MED and ET3MED.
Request a price and lead time
ET3 / ET1 — dry-type LV power transformers up to 2 500 kVA, including water-cooled and with the APS pre-magnetizing system. We reply within one business day.
Or email office@usk.ua or call +38 (044) 339-50-20.
FAQ
What power and voltage do ET3 and ET1 transformers have?
Three-phase ET3 are made from 40 to 2 500 kVA, single-phase ET1 up to 100 kVA. Winding voltage is up to 1 100 V, and the standard vector group is Dyn5.
Can a water-cooled transformer be ordered?
Yes, the WF version has an insulated cooler made of copper or aluminium tube or aluminium panels inside the windings. The manufacturer declares up to 95 % of heat losses carried into the water.
What is the APS option in a dry-type transformer for?
It pre-magnetizes the core through resistors and eliminates the magnetizing inrush current at switching on. This reduces voltage dips and false protection trips in weak networks.
Which protection ratings are available for ET3?
IP00, IP23, IP44, IP54 and IP66, as well as NEMA 3/3R and 4/4X. Temperature sensors, wheels and vibration isolators can be ordered in addition.
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Need a price, lead time or replacement?
Send us a request and we will confirm the configuration, lead time and delivery terms. We reply by email.