Oil-Immersed Distribution Transformer

S20 / S22 · 0–35 kV series

Oil-immersed transformers for utility, industrial and renewable networks. The parameters below show the 12 kV distribution example.

Rated power: 30–2500kVA
High voltage: 6–11kV
Frequency: 50 / 60Hz

Ratings and dimensions

12 kV oil-immersed distribution transformer — Series photographs show different specifications. Parameters on this page: 12 kV distribution.

Series photographs show different specifications. Parameters on this page: 12 kV distribution.

12 kV parameter example

35 kV and below oil-immersed transformers are core equipment in the power system, widely used in urban and rural grid transformation, industrial and mining enterprises, new-energy generation and construction.

Mainstream products reach the national secondary energy-efficiency standard (S20 series): no-load loss 20–30% lower than the traditional S13 type and load loss 10–15% lower.

Ratings and dimensions

12 kV distribution — ratings and dimensions

Rated power (kVA)	No-load loss (kW)	Load loss (kW)	No-load current (%)	Short-circuit impedance (%)	Overall dimensions (mm)						Weight (kg)
Rated power (kVA)	No-load loss (kW)	Load loss (kW)	No-load current (%)	Short-circuit impedance (%)	L	W	E	S	A	B	Weight (kg)
30	0.065	0.455	1.2	4	630	380	600	190	400	660	350
50	0.080	0.655	1.04	4	730	400	680	200	400	660	400
63	0.090	0.785	0.96	4	750	430	690	215	400	660	570
80	0.105	0.945	0.96	4	780	430	700	215	400	660	600
100	0.120	1.140	0.88	4	800	450	730	225	400	660	650
125	0.135	1.360	0.88	4	850	490	750	245	400	660	700
160	0.160	1.665	0.8	4	950	550	900	275	400	660	830
200	0.190	1.970	0.8	4	1050	600	930	300	660	660	900
250	0.230	2.300	0.72	4	1080	600	950	300	660	660	1000
315	0.270	2.760	0.72	4	1200	750	1000	375	660	660	1210
400	0.330	3.250	0.64	4	1350	880	1190	440	660	660	1450
500	0.385	3.900	0.64	4	1400	910	1230	455	660	660	1680
630	0.460	4.460	0.48	4.5	1500	950	1270	475	660	660	1980
800	0.560	5.400	0.48	4.5	1830	1220	1270	580	820	820	2470
1000	0.665	7.415	0.48	4.5	1790	1290	1380	610	820	820	2680
1250	0.780	8.640	0.4	4.5	1820	1350	1450	620	820	820	3110
1600	0.940	10.44	0.4	4.5	1960	1480	1500	680	820	820	3850
2000	1.085	13.18	0.32	5	2020	1450	1550	690	820	1070	4600
2500	1.280	15.27	0.32	5	2090	1510	1290	700	820	1070	5550

PEI complies with EU Tier 2 requirements under (EU) 2019/1783 and (EU) No 548/2014.

Outline drawing

Dimension letters on the drawing correspond to the columns of the ratings table. Overall dimensions are for reference only; the official drawings provided by Tianyu prevail.

Design and performance

Functional features

High efficiency: Cold-rolled silicon steel with 45° full-mitre joints and amorphous-alloy options; no-load loss reduced by more than 30%.
Sealed tank: Fully sealed corrugated oil tank prevents leakage and suits harsh outdoor environments.
Short-circuit strength: Body structure designed to withstand sudden short-circuit impact.
Intelligent O&M: Remote monitoring with telesignalling, telemetry, teleregulation and telecontrol.
Maintenance-free: Suspended-core-free design reduces maintenance cost.
Aluminium core option: Aluminium-core design for new-energy projects reduces life-cycle carbon emissions.

Product advantages

Foil-wound LV coils: Whole series uses low-voltage copper-foil winding for short-circuit resistance well above industry level.
Lower lead resistance: Insulating LV clamps reduce lead resistance in oil by 10–15%; load loss 1–3% below the industry advanced level.
Standardised design: Step-by-step standardised design for rapid design, production and delivery.
Anti-corrosion: Acid washing, phosphating and three-proof paint; anti-corrosion up to C5-H.

Application scope

Outdoor electrical substation with transformers, switchgear and overhead power lines

PowerDistribution network upgrades, civil power supply, substations, renewable-energy grid connection.
IndustryFactory distribution rooms and large power-equipment supply.
TransportationPublic infrastructure, electric traction and lighting supply.
ConstructionCommercial plazas, communication buildings, residential areas, temporary supply.
Power generationLarge motors, circulating water pumps, induced-draft fans and other auxiliaries.

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Need a rating that is not listed?

Send the capacity, voltage ratio, vector group, impedance and site conditions. Engineering confirms the design against the approved project specification.

Certificates and reports