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S20-M Series Oil-Immersed Transformers

162 Models available

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S20-M Oil-Immersed Transformers

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S20-M Series - Premium Energy-Efficient Sealed Oil-Immersed Transformers (Level 20 Efficiency)

The S20-M series represents the highest energy efficiency class for oil-immersed transformers, achieving Level 20 rating with exceptional performance. Rated 10–5000 kVA, 0.48–35 kV primary and 0.208–0.48 kV secondary, mineral-oil insulation with 65 K temperature rise. Suitable for utility distribution networks, substations, solar farms, and industrial power systems.

Model Number Breakdown

20Performance level designation, corresponds to Level 20 energy efficiency standard
SThree-phase power transformer
MSealed construction, maintenance-free design
162+
Available Models
Instant Selection & Quote Calculator
Engineering Calculators

Key Features

  • Level 20 energy efficiency rating (premium class)
  • Minimal energy losses
  • Advanced sealed construction
  • Optimal for modern power grids

Applications

  • Smart grid infrastructure
  • High-efficiency power distribution
  • Modern utility systems
  • Premium commercial applications

TECHNICAL DRAWING

Model: S20-M-250/10/0.48 | Type: Oil-immersed transformer | Capacity: 250 kVA

FRONT ELEVATION

Oil level1U1V1W2U2V2W2NTAPN.P.180mm240mm

ELECTRICAL SCHEMATIC

HV WINDING (Delta)1U1V1WLV WINDING (Star)2U2V2W2NDelta-Wye (IEEE Std)

EFFICIENCY vs LOAD

90%95%98%99%0%25%50%75%100%≈99%load %efficiency %

SIDE VIEW

Oil level135mm

TOP VIEW

1U1V1W2U2V2W2N135mm

TERMINAL BLOCK

HV TERMINAL BLOCK1U1V1W1N1PELV TERMINAL BLOCK2U2V2W2N2PE2122Terminal block configurationTin-plated copper busbar

CORE & WINDING

OIL / TANKHV winding/bushingINSULATIONLV winding/bushingIron coreconcentric cross-section
LEGEND:
Iron core
HV winding/bushing
LV winding/bushing
Dimension line

Specifications Range

All specifications and dimensions can be customized upon request

Model Selector

Key parametersModel Range
Capacity10–5000 kVA
HV Voltage (kV)10, 6, 35, 0.48
LV Voltage (kV)0.4, 0.48, 0.22, 0.208
Frequency (Hz)50, 60
Impedance (%)4, 4.5, 6, 7
CoolingONAN
EfficiencyClass 20
StandardIEC 60076, IEEE C57 / ANSI C84.1
ConnectionDyn11 (IEC), Delta-Wye (IEEE Std)
Insulation classA (105°C)
Allowed temperature rise65
Noise level≤33 dB(A), ≤34 dB(A), ≤35 dB(A), ≤36 dB(A), ≤37 dB(A), ≤38 dB(A)…
Tap Changer±2×2.5% Multi-tap, ±5% Single-tap, ±5×2.5% Multi-tap
No-load loss42–2139 W
Load loss255–25720 W
Select 2-3 models to compare
CompareModelCapacity (kVA)HV Voltage (kV)LV Voltage (kV)WeightDimensions
S20-M-10/10/0.410kVA100.4229 kg650×362×577 mm
S20-M-10/6/0.410kVA60.4229 kg650×362×577 mm
S20-M-10/35/0.410kVA350.4229 kg650×362×577 mm
S20-M-10/10/0.4810kVA100.48229 kg650×362×577 mm
S20-M-10/10/0.2210kVA100.22229 kg650×362×577 mm
S20-M-10/0.48/0.20810kVA0.480.208229 kg650×362×577 mm
S20-M-15/10/0.415kVA100.4247 kg675×382×596 mm
S20-M-15/6/0.415kVA60.4247 kg675×382×596 mm
S20-M-15/35/0.415kVA350.4247 kg675×382×596 mm
S20-M-15/10/0.4815kVA100.48247 kg675×382×596 mm
S20-M-15/10/0.2215kVA100.22247 kg675×382×596 mm
S20-M-15/0.48/0.20815kVA0.480.208247 kg675×382×596 mm
S20-M-20/10/0.420kVA100.4265 kg700×402×615 mm
S20-M-20/6/0.420kVA60.4265 kg700×402×615 mm
S20-M-20/35/0.420kVA350.4265 kg700×402×615 mm
S20-M-20/10/0.4820kVA100.48265 kg700×402×615 mm
S20-M-20/10/0.2220kVA100.22265 kg700×402×615 mm
S20-M-20/0.48/0.20820kVA0.480.208265 kg700×402×615 mm
S20-M-25/10/0.425kVA100.4288 kg784×443×634 mm
S20-M-25/6/0.425kVA60.4288 kg784×443×634 mm
S20-M-25/35/0.425kVA350.4288 kg784×443×634 mm
S20-M-25/10/0.4825kVA100.48288 kg784×443×634 mm
S20-M-25/10/0.2225kVA100.22288 kg784×443×634 mm
S20-M-25/0.48/0.20825kVA0.480.208288 kg784×443×634 mm
S20-M-30/10/0.430kVA100.4311 kg869×483×654 mm
S20-M-30/6/0.430kVA60.4311 kg869×483×654 mm
S20-M-30/35/0.430kVA350.4311 kg869×483×654 mm
S20-M-30/10/0.4830kVA100.48311 kg869×483×654 mm
S20-M-30/10/0.2230kVA100.22311 kg869×483×654 mm
S20-M-30/0.48/0.20830kVA0.480.208311 kg869×483×654 mm
S20-M-40/10/0.440kVA100.4370 kg884×491×673 mm
S20-M-40/6/0.440kVA60.4370 kg884×491×673 mm
S20-M-40/35/0.440kVA350.4370 kg884×491×673 mm
S20-M-40/10/0.4840kVA100.48370 kg884×491×673 mm
S20-M-40/10/0.2240kVA100.22370 kg884×491×673 mm
S20-M-40/0.48/0.20840kVA0.480.208370 kg884×491×673 mm
S20-M-50/10/0.450kVA100.4430 kg899×499×692 mm
S20-M-50/6/0.450kVA60.4430 kg899×499×692 mm
S20-M-50/35/0.450kVA350.4430 kg899×499×692 mm
S20-M-50/10/0.4850kVA100.48430 kg899×499×692 mm
S20-M-50/10/0.2250kVA100.22430 kg899×499×692 mm
S20-M-50/0.48/0.20850kVA0.480.208430 kg899×499×692 mm
S20-M-63/10/0.463kVA100.4480 kg944×519×727 mm
S20-M-63/6/0.463kVA60.4480 kg944×519×727 mm
S20-M-63/35/0.463kVA350.4480 kg944×519×727 mm
S20-M-63/10/0.4863kVA100.48480 kg944×519×727 mm
S20-M-63/10/0.2263kVA100.22480 kg944×519×727 mm
S20-M-63/0.48/0.20863kVA0.480.208480 kg944×519×727 mm
S20-M-80/10/0.480kVA100.4549 kg999×547×769 mm
S20-M-80/6/0.480kVA60.4549 kg999×547×769 mm
S20-M-80/35/0.480kVA350.4549 kg999×547×769 mm
S20-M-80/10/0.4880kVA100.48549 kg999×547×769 mm
S20-M-80/10/0.2280kVA100.22549 kg999×547×769 mm
S20-M-80/0.48/0.20880kVA0.480.208549 kg999×547×769 mm
S20-M-100/10/0.4100kVA100.4597 kg990×670×930 mm
S20-M-100/6/0.4100kVA60.4597 kg990×670×930 mm
S20-M-100/35/0.4100kVA350.4597 kg990×670×930 mm
S20-M-100/10/0.48100kVA100.48597 kg990×670×930 mm
S20-M-100/10/0.22100kVA100.22597 kg990×670×930 mm
S20-M-100/0.48/0.208100kVA0.480.208597 kg990×670×930 mm
S20-M-125/10/0.4125kVA100.4668 kg1079×579×846 mm
S20-M-125/6/0.4125kVA60.4668 kg1079×579×846 mm
S20-M-125/35/0.4125kVA350.4668 kg1079×579×846 mm
S20-M-125/10/0.48125kVA100.48668 kg1079×579×846 mm
S20-M-125/10/0.22125kVA100.22668 kg1079×579×846 mm
S20-M-125/0.48/0.208125kVA0.480.208668 kg1079×579×846 mm
S20-M-160/10/0.4160kVA100.4764 kg1045×685×965 mm
S20-M-160/6/0.4160kVA60.4764 kg1045×685×965 mm
S20-M-160/35/0.4160kVA350.4764 kg1045×685×965 mm
S20-M-160/10/0.48160kVA100.48764 kg1045×685×965 mm
S20-M-160/10/0.22160kVA100.22764 kg1045×685×965 mm
S20-M-160/0.48/0.208160kVA0.480.208764 kg1045×685×965 mm
S20-M-200/10/0.4200kVA100.4842 kg1120×750×1000 mm
S20-M-200/6/0.4200kVA60.4842 kg1120×750×1000 mm
S20-M-200/35/0.4200kVA350.4842 kg1120×750×1000 mm
S20-M-200/10/0.48200kVA100.48842 kg1120×750×1000 mm
S20-M-200/10/0.22200kVA100.22842 kg1120×750×1000 mm
S20-M-200/0.48/0.208200kVA0.480.208842 kg1120×750×1000 mm
S20-M-250/10/0.4250kVA100.4960 kg1189×829×1000 mm
S20-M-250/6/0.4250kVA60.4960 kg1189×829×1000 mm
S20-M-250/35/0.4250kVA350.4960 kg1189×829×1000 mm
S20-M-250/10/0.48250kVA100.48960 kg1189×829×1000 mm
S20-M-250/10/0.22250kVA100.22960 kg1189×829×1000 mm
S20-M-250/0.48/0.208250kVA0.480.208960 kg1189×829×1000 mm
S20-M-315/10/0.4315kVA100.41150 kg1350×930×1040 mm
S20-M-315/6/0.4315kVA60.41150 kg1350×930×1040 mm
S20-M-315/35/0.4315kVA350.41150 kg1350×930×1040 mm
S20-M-315/10/0.48315kVA100.481150 kg1350×930×1040 mm
S20-M-315/10/0.22315kVA100.221150 kg1350×930×1040 mm
S20-M-315/0.48/0.208315kVA0.480.2081150 kg1350×930×1040 mm
S20-M-400/10/0.4400kVA100.41349 kg1300×860×1090 mm
S20-M-400/6/0.4400kVA60.41349 kg1300×860×1090 mm
S20-M-400/35/0.4400kVA350.41349 kg1300×860×1090 mm
S20-M-400/10/0.48400kVA100.481349 kg1300×860×1090 mm
S20-M-400/10/0.22400kVA100.221349 kg1300×860×1090 mm
S20-M-400/0.48/0.208400kVA0.480.2081349 kg1300×860×1090 mm
S20-M-500/10/0.4500kVA100.41504 kg1390×960×1120 mm
S20-M-500/6/0.4500kVA60.41504 kg1390×960×1120 mm
S20-M-500/35/0.4500kVA350.41504 kg1390×960×1120 mm
S20-M-500/10/0.48500kVA100.481504 kg1390×960×1120 mm
S20-M-500/10/0.22500kVA100.221504 kg1390×960×1120 mm
S20-M-500/0.48/0.208500kVA0.480.2081504 kg1390×960×1120 mm
S20-M-630/10/0.4630kVA100.41818 kg1465×1020×1160 mm
S20-M-630/6/0.4630kVA60.41818 kg1465×1020×1160 mm
S20-M-630/35/0.4630kVA350.41818 kg1465×1020×1160 mm
S20-M-630/10/0.48630kVA100.481818 kg1465×1020×1160 mm
S20-M-630/10/0.22630kVA100.221818 kg1465×1020×1160 mm
S20-M-630/0.48/0.208630kVA0.480.2081818 kg1465×1020×1160 mm
S20-M-800/10/0.4800kVA100.42136 kg1525×1060×1200 mm
S20-M-800/6/0.4800kVA60.42136 kg1525×1060×1200 mm
S20-M-800/35/0.4800kVA350.42136 kg1525×1060×1200 mm
S20-M-800/10/0.48800kVA100.482136 kg1525×1060×1200 mm
S20-M-800/10/0.22800kVA100.222136 kg1525×1060×1200 mm
S20-M-800/0.48/0.208800kVA0.480.2082136 kg1525×1060×1200 mm
S20-M-1000/10/0.41000kVA100.42522 kg1750×1270×1230 mm
S20-M-1000/6/0.41000kVA60.42522 kg1750×1270×1230 mm
S20-M-1000/35/0.41000kVA350.42522 kg1750×1270×1230 mm
S20-M-1000/10/0.481000kVA100.482522 kg1750×1270×1230 mm
S20-M-1000/10/0.221000kVA100.222522 kg1750×1270×1230 mm
S20-M-1000/0.48/0.2081000kVA0.480.2082522 kg1750×1270×1230 mm
S20-M-1250/10/0.41250kVA100.42943 kg1720×1240×1300 mm
S20-M-1250/6/0.41250kVA60.42943 kg1720×1240×1300 mm
S20-M-1250/35/0.41250kVA350.42943 kg1720×1240×1300 mm
S20-M-1250/10/0.481250kVA100.482943 kg1720×1240×1300 mm
S20-M-1250/10/0.221250kVA100.222943 kg1720×1240×1300 mm
S20-M-1250/0.48/0.2081250kVA0.480.2082943 kg1720×1240×1300 mm
S20-M-1600/10/0.41600kVA100.44069.5 kg1879×1312×1492 mm
S20-M-1600/6/0.41600kVA60.44069.5 kg1879×1312×1492 mm
S20-M-1600/35/0.41600kVA350.44069.5 kg1879×1312×1492 mm
S20-M-1600/10/0.481600kVA100.484069.5 kg1879×1312×1492 mm
S20-M-1600/10/0.221600kVA100.224069.5 kg1879×1312×1492 mm
S20-M-1600/0.48/0.2081600kVA0.480.2084069.5 kg1879×1312×1492 mm
S20-M-2000/10/0.42000kVA100.44572.5 kg1999×1368×1538 mm
S20-M-2000/6/0.42000kVA60.44572.5 kg1999×1368×1538 mm
S20-M-2000/35/0.42000kVA350.44572.5 kg1999×1368×1538 mm
S20-M-2000/10/0.482000kVA100.484572.5 kg1999×1368×1538 mm
S20-M-2000/10/0.222000kVA100.224572.5 kg1999×1368×1538 mm
S20-M-2000/0.48/0.2082000kVA0.480.2084572.5 kg1999×1368×1538 mm
S20-M-2500/10/0.42500kVA100.45304 kg2179×1062×1515 mm
S20-M-2500/6/0.42500kVA60.45304 kg2179×1062×1515 mm
S20-M-2500/35/0.42500kVA350.45304 kg2179×1062×1515 mm
S20-M-2500/10/0.482500kVA100.485304 kg2179×1062×1515 mm
S20-M-2500/10/0.222500kVA100.225304 kg2179×1062×1515 mm
S20-M-2500/0.48/0.2082500kVA0.480.2085304 kg2179×1062×1515 mm
S20-M-3150/10/0.43150kVA100.46310 kg2299×1167×1615 mm
S20-M-3150/6/0.43150kVA60.46310 kg2299×1167×1615 mm
S20-M-3150/35/0.43150kVA350.46310 kg2299×1167×1615 mm
S20-M-3150/10/0.483150kVA100.486310 kg2299×1167×1615 mm
S20-M-3150/10/0.223150kVA100.226310 kg2299×1167×1615 mm
S20-M-3150/0.48/0.2083150kVA0.480.2086310 kg2299×1167×1615 mm
S20-M-4000/10/0.44000kVA100.47590 kg2498×1247×1730 mm
S20-M-4000/6/0.44000kVA60.47590 kg2498×1247×1730 mm
S20-M-4000/35/0.44000kVA350.47590 kg2498×1247×1730 mm
S20-M-4000/10/0.484000kVA100.487590 kg2498×1247×1730 mm
S20-M-4000/10/0.224000kVA100.227590 kg2498×1247×1730 mm
S20-M-4000/0.48/0.2084000kVA0.480.2087590 kg2498×1247×1730 mm
S20-M-5000/10/0.45000kVA100.49145 kg2698×1328×1845 mm
S20-M-5000/6/0.45000kVA60.49145 kg2698×1328×1845 mm
S20-M-5000/35/0.45000kVA350.49145 kg2698×1328×1845 mm
S20-M-5000/10/0.485000kVA100.489145 kg2698×1328×1845 mm
S20-M-5000/10/0.225000kVA100.229145 kg2698×1328×1845 mm
S20-M-5000/0.48/0.2085000kVA0.480.2089145 kg2698×1328×1845 mm

Selection Guide

1

Efficiency-first

Select S20-M for the lowest losses - green buildings, high energy-cost regions or efficiency mandates.

2

Upgrade path

A drop-in replacement for older S9/S11 units with the same footprint.

3

Lifecycle cost

Evaluate total lifetime cost, not just purchase price - lowest losses win over time.

- Frequently Asked Questions

What efficiency level is S20-M?

S20-M represents the latest high-efficiency oil-immersed generation with the lowest losses in the S-series.

Is S20-M worth the higher cost?

For continuously loaded transformers, energy savings usually recover the premium within a few years.

Can S20-M replace older S9/S11 units?

Yes, it is a drop-in upgrade with the same footprint and higher efficiency.

Instant Selection & Quote Calculator

Select your specifications to get an estimated price instantly.

1 · Configure
More options(6)
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2 · Your price
Derived Ratings (calculated from the configuration)

The values below are computed from what you selected above. Anything that cannot be computed yet is shown as an em dash — never as zero.

Iₙ = S / (√3·U) · I_sc = 100·Iₙ / uₖ · S_sc = √3·U·I_sc · I_p = k·Iₖ

Inputs taken from the configuration
Capacity: — kVAfrom the configuration above
System voltage: not specified
Impedance voltage uₖ: not specified
Result
Rated current Iₙ—
Short-circuit current I_sc—
Short-circuit current I_sc—
Short-circuit power S_sc—
I_sc is calculated on the transformer impedance basis alone (system impedance neglected) — the same basis used in IEC 60076-5 short-circuit calculations.
System voltage → —

Still required to complete the calculation: rated capacity S, impedance voltage uₖ, short-time or peak withstand current.

Per-model values (P0 / Pk / uₖ declared by the factory, losses, noise, temperature rise, dimensions, weight) are not in the product library: those rows stay at an em dash until the factory parameter sheet is supplied. An em dash means the value is unavailable — it is never rendered as zero.

Derived losses (from the selected efficiency grade + capacity)
Class 3 (S13)
No-load loss P0 (kW)—
Load loss Pk (kW)—

Read-only: no price factor, not part of the sum — the loss-grade cost is already carried by the efficiency (subtype) base price, so charging here would double-bill. Values come from the product library type-test data, interpolated between published capacities; grades the library does not cover show an em dash, never zero.

S13 系列（产品库 S13-M / 卷铁芯 S13-M.RL，Class 3）

Reference prices are for estimation only and do not constitute a formal offer.

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