2000 KVA Oil Filled Transformer

At 2,000 kVA the transformer stops being a catalogue item. Below this rating most buyers line up two data sheets and take the cheaper one. At this size the numbers start pushing each other around: the impedance you accept sets the fault current your switchgear has to interrupt, the cooling class decides how much load you can carry through the hottest week of the year, and the losses you sign off run on an electricity bill for the next two and a half decades.

The 2000 KVA Oil Filled Transformer is built at our works in Baoding, Hebei, in sealed-tank and conservator designs, with corrugated or radiator tanks depending on the rating and the site. This page covers the 33 kV / 400 V ONAN build in detail. Other voltage classes up to 33 kV come off the same core-and-coil designs, against a project specification rather than a catalogue number.

Oil-filled units in the assembly bay before dispatch

Standard ratings and currents

Primary	Secondary	Primary current	Secondary current	Cooling	Typical duty
10 kV	400 V	115.5 A	2,886.8 A	ONAN / ONAF	Plant MV/LV substation
11 kV	415 V	105 A	2,782 A	ONAN	Utility distribution, EPC packages
22 kV	415 V	52.5 A	2,782 A	ONAN / ONAF	Long MV feeders, mining
33 kV	400 V	35 A	2,886.8 A	ONAN	33 kV step-down (this page's build)

Currents are calculated at rated power and rated voltage: I = S / (√3 × V). Two of these numbers move, and both cause trouble when they are discovered late. Drop the secondary from 415 V to 400 V and the LV current climbs from 2,782 A to 2,887 A - often enough to push you into the next busbar size and a different breaker frame. Raise the primary from 10 kV to 33 kV and the HV current falls to 35 A, while the insulation level, clearances and oil volume all rise. A 33 kV unit is not a 10 kV unit with a different nameplate on it.

Outline drawing accompanying the quotation - confirm mounting centres and clearances against it

Dual-secondary, split-winding and non-standard impedance versions are built to order. Tell us your actual secondary voltage before we quote: 400 V and 415 V look interchangeable on a tender, and they are not.

Why oil-filled at this rating

The oil does two jobs. It carries heat from the windings out to the tank wall or the radiator bank, and it insulates the live parts from each other and from earth. The second job is the one buyers forget. Oil has several times the dielectric strength of air, so inside a sealed tank the clearances at 33 kV can be a fraction of what an air-insulated design needs. The core and coils end up smaller, and so does the footprint.

ONAN covers most of what we ship at this size: the oil circulates by natural convection and the tank surface does the radiating. If your duty cycle has long peaks above nameplate, order the tank ONAF-capable now and run it ONAN. The fan bank adds roughly a quarter more capacity out of the same core and coils the day you need it, and both the fans and the extra tank stiffness have to be designed in from the start - so ask at enquiry stage, not after the plinth is poured.

What you give up is containment. An oil-filled unit needs a bunded plinth, oil retention and fire separation from occupied buildings. Where none of those are available (a shopping centre basement, a tunnel, a hospital), a dry-type unit is the right answer, and we build those in the same works. For an outdoor yard or a dedicated substation room, oil-filled is cheaper per kVA, quieter, repairable on site by your own team, and considerably more forgiving of sustained overload.

Tank details: HV bushings, gas relay, pressure relief valve, oil temperature gauge

The parameters that decide whether the unit lasts

Impedance (%Z). This unit is built to 6 %. That figure is not a quality score, it is a design choice with consequences. At 6 % the 400 V busbar sees a fault current of roughly 48 kA. Trim the impedance below 5 % and the same busbar sees nearly 58 kA - the difference between a 50 kA and a 65 kA breaker frame, and between one switchgear package and the next one up. Check the quoted impedance against your breaker rating before you accept any offer, including ours.

Losses. Every unit ships with a routine test report showing measured no-load and load loss, and both belong in your evaluation. They do not weigh equally: at this rating the no-load component runs twenty-four hours a day for the life of the transformer, whether the plant is producing or not, so its cost is easy to underestimate at tender stage. If your specification carries a loss capitalisation formula, send it over and we will quote the grade that wins on 25-year total cost rather than the cheapest unit on day one.

Temperature rise. Oil-immersed units at this rating are normally designed to 55 K / 60 K. Those figures assume site ambient at or below 40 °C and installation at or below 1,000 m. Above either - a Gulf coast yard, a mine at 1,800 m - loading has to be corrected under IEC 60076-2. Tell us at enquiry stage, not at commissioning: correcting it later means a de-rated transformer or a second cooling stage.

Vector group. For a 33/0.4 kV step-down the usual arrangement is Dyn11 with the neutral brought out. Confirm it against your single-line diagram, because it decides what your earth-fault protection sees.

Tap range. ±2 × 2.5 % off-circuit tapping is standard, which covers everyday supply drift and has nothing to maintain. Ask for an OLTC only if you genuinely have to regulate while the plant is running. It adds cost, oil volume, a control cabinet and a maintenance item for the life of the unit.

Manufacturing and testing

Our site covers 33,300 m² with 260 employees and an annual capacity above 1,000 MVA. Eighteen engineers handle design and type-test work. Cores are step-lapped from cold-rolled grain-oriented silicon steel, and windings are copper, vacuum-dried before oil filling. Tanks are welded and pressure-tested, and every unit is oil-filled and leak-tested before it is crated.

Coil winding, vacuum drying and high-voltage testing, all in-house

The 2000 KVA Oil Filled Transformer leaves the works with a routine test report to IEC 60076-1: winding resistance, ratio and vector group, no-load loss and no-load current, impedance voltage and load loss, applied voltage and induced voltage. Lightning impulse, temperature rise, short-circuit and noise measurements are available as type tests, with third-party witnessing if your contract requires it. ISO 9001:2015 covers the process, and CE, UL and RoHS documentation is issued on request.

Quality management, CE conformity and product certification held by the works

Recent work out of the same works includes 8 × 160 kVA units to Laos, 5 × 100 kVA to Iran, 30 × 200 kVA to Oman, and a custom 4,000 kVA 11/0.415 kV unit with side outgoing lines for a customer in South Africa - different ratings, same process.

Custom unit with side outgoing lines, built for a customer in South Africa

Core cutting, winding, assembly and test equipment on our own floor

How an order moves through the works, from contract review to final inspection

Packing, lead time, warranty

MOQ is one unit. Standard export packing is a seaworthy wooden crate with the transformer braced to the base plate. Pallets and rack frames are available if the site has a crane limit. Lead time is quoted per order: for a standard rating on an existing design it is measured in weeks, not months. Warranty is 24 months. OEM and ODM are available, including your nameplate, your drawing numbers and your test report format. Technical support runs 7×24, before the order as well as after it.

Export packing: braced to the base, then closed in a seaworthy case

What to send for a firm quotation

Nine items and we can quote without another round of emails:

1. Rated power (confirm 2,000 kVA) and number of phases
2. Primary and secondary voltage, and whether the LV neutral is brought out
3. Frequency: 50 Hz or 60 Hz
4. Vector group, if your specification fixes it
5. Impedance, if your specification fixes it
6. Loss limits, or your loss capitalisation formula
7. Indoor or outdoor, and the clearances you have on site
8. Site ambient temperature, altitude and seismic zone
9. Applicable standard, and any third-party inspection requirement

FAQ

How many amps is a 2000 kVA transformer?
On the 33 kV / 400 V build the primary current is 35 A and the secondary current is 2,886.8 A. Move the primary to 11 kV and it rises to 105 A; move the secondary to 415 V and the LV current drops to 2,782 A. The LV figure is the one that sizes your busbar, so fix it before the switchgear is ordered.

Is 2000 kVA the same as 2 MVA?
Yes - the same rating, written two ways. If a specification mixes the two terms, check whether the secondary voltage has moved as well. The 2 MVA oil-immersed transformer built in the same works is this unit under its other name.

How much does it weigh, and what floor space does it need?
Both are issued on the approved outline drawing for your specific build, because tank type, radiator area and oil volume all move them. Ask for that drawing at enquiry stage and pour the plinth against it. A 33 kV unit of this rating is taller and heavier than the same rating at 10 kV, so a generic figure is not a safe basis for foundations or crane capacity.

Can it be installed indoors?
Yes. The standard unit is built for indoor installation, and most of ours go into a dedicated substation room. That room still needs oil containment and fire separation under your local code. If containment is impossible, take the dry-type route instead.

Do you issue test reports before shipping?
Yes. Routine test reports come from our own works and ship with the unit. Third-party witness testing can be arranged through your nominated inspection body if the contract calls for it.

Get a priced offer

A 2000 KVA Oil Filled Transformer is sized to your fault level, your ambient and your load profile, not against a list price. Send us those three, even as rough numbers, and you will get a priced offer together with a preliminary outline drawing. If you are still weighing 10 kV against 11 kV, or wondering whether to buy a 2.5 MVA transformer now for load you expect in three years, say so - we will tell you which one suits your site rather than which one is easier for us to build.

Baoding Zhongyi Electric Corporation · MOQ 1 unit · 24-month warranty · 7×24 technical support · Send your specification and we will come back with a price