Oil-Immersed Distribution Transformers (S11 / S13 / Amorphous)

Type Description

Lower loss, larger capacity, smaller footprint.

Suitable for both indoor and outdoor service environments with no special requirement beyond standard fire protection. The S11 platform delivers lower loss, larger capacity, lower installed cost, and strong overload capacity in a compact tank footprint, and is widely specified across domestic and international distribution networks.

Rated High Voltage10 / 20 / 35kV

Rated Low Voltage0.4kV – 10kV

Vector GroupsDyn11 · Yyn0 · YNd11 · Yd11

CoolingNatural Oil Circulation

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S11 oil-immersed distribution transformer — three-phase, corrugated tank

Applied StandardGB1094 · IEC60076

Insulating MediumMineral Oil

Tank TypeSealed, Corrugated

Std. ReferenceGB/T6451-2008

Protection & Monitoring

Standard protective fittings, sized to capacity.

Gas relay & temperature controller — required equipment on every unit rated 630kVA and above, per Chibo's standard fitting policy.
Top-mounted HV bushings with porcelain insulators sized to the 10/20/35kV class, visible on the tank lid assembly.
Dial-type oil temperature gauge fitted to the tank lid for on-site thermal monitoring.
Drain & sampling valve at the base of the tank for routine oil sampling and maintenance.

Oil-immersed transformer fitted with HV bushings, gas relay, and tank radiator fins

Series Comparison

Three loss profiles, one footprint family.

Baseline series

S11 Series

The reference platform for the full rating table below — lower loss, larger capacity, strong overload capacity, compact tank.

−30% no-load loss vs. S11

S13 Series

Lower loss, lower noise, more compact structure than S11. Positioned as the energy-saving promotion product for grid-renewal projects.

Amorphous alloy core oil-immersed transformer

−70% no-load loss vs. S11

Amorphous Alloy Series

Amorphous alloy core construction — the lowest no-load loss and noise in the range, with a simplified core structure.

Engineering Parameters Matrix

S11 Series — full rating table, 10kV class.

Rated voltage combinations: HV 6 / 6.3 / 10 / 10.5 / 11kV with ±5% or ±2×2.5% tap range; LV 0.4kV. Vector group: Dyn11 or Yyn0.

Rated Power (kVA)	No-Load Loss (W)	No-Load Current (%)	Load Loss @75°C (W)	Uk (%)	Weight (kg)	Dimension L×W×H (mm)
30	100	2.1	630	4	330	780×650×1000
50	130	2.0	910	4	410	830×650×1070
80	180	1.8	1310	4	510	870×710×1085
100	200	1.6	1580	4	600	900×740×1130
125	240	1.5	1890	4	650	910×720×1155
160	280	1.4	2310	4	770	930×750×1185
200	340	1.3	2730	4	900	980×770×1250
250	400	1.2	3200	4	1070	1010×800×1280
315	480	1.1	3830	4	1200	1040×900×1300
400	570	1.0	4520	4	1410	1070×870×1405
500	680	1.0	5410	4	1600	1180×900×1440
630	810	0.9	6200	4.5	1860	1240×980×1590
800	980	0.8	7500	4.5	2230	1320×1030×1555
1000	1150	0.7	10300	4.5	2520	1640×1120×1590
1250	1360	0.6	12000	4.5	3030	1710×1180×1680
1600	1640	0.5	14500	4.5	3630	1770×1230×1775
2000	1960	0.5	16800	5.5	4530	2000×1350×2020
2500	2310	0.4	19800	5.5	5180	2070×1340×2150
3150	2730	0.4	23200	5.5	6750	2070×2120×2000

Above dimensions and data are for reference only — actual values to be confirmed by factory at order placement. Gas relay & temperature controller equipped as standard on units of 630kVA and above.

Applied Standards & Insulation Class

Insulation level by HV class.

HV Class	Vector Groups	LV Range	Insulation Level (HV / LV)
10kV	Dyn11 / Yyn0 / YNd11 / Yd11	0.4kV – 10kV	LI75 AC35 / LI0 AC5
20kV	Dyn11 / Yyn0 / YNd11 / Yd11	0.4kV – 10kV	LI125 AC55 / LI0 AC5
35kV	Dyn11 / Yyn0 / YNd11 / Yd11	0.4kV – 10kV	LI200 AC85 / LI0 AC5

Applied standards: GB1094.1.2-1996, GB1094.3-2003, GB1094.5-2003, GB/T6451-2008, IEC60076.

Service Conditions

Rated environment envelope.

Ambient Temperature−30°C to +40°C

Altitude≤ 2000m

Relative Humidity≤ 90% (+25°C)

Wind Speed≤ 35 m/s

Seismic — Horizontal≤ 0.4 m/s²

Seismic — Vertical≤ 0.2 m/s²

Site RestrictionsKeep clear of fire, explosion risk, dirty/chemically corrosive atmosphere, and strenuous vibration sources

Need a special or dry-type build instead?

Chibo's range also covers special-application transformers and epoxy cast-resin dry-type units — both covered by the 1-year standard warranty, with free end-of-life recycling on scrapped cast-resin units.

View Special & Dry-Type Transformers