Distribution Transformers

S11/13/20/22-M▪D Series Three-Phase Oil-Immersed Underground Transformer

Product Overview

S11/13/20/22-M▪D Series

S11/13/20/22-M▪D Series oil-immersed underground transformer, is a type of power equipment that places main devices such as transformers underground, featuring fully sealed design, underground installation, high energy efficiency, safety and reliability. It breaks the traditional above-ground setup of transformers, and is widely applied in urban distribution networks, industrial parks, residential areas and other fields, providing important support for modern urban power supply.

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Product Features

Energy Efficiency
Adopts low-loss materials and energy-saving structural design, significantly reducing no-load/short-circuit losses and enhancing energy utilization efficiency, compliant with green and low-carbon standards.
Fully Sealed for Reliable Operation
With fully sealed and insulated design, achieving IP68 rating for moisture/water/dust protection. Equipped with high-efficiency heat dissipation system to ensure long-term stable power supply in harsh environments.
Environment-Friendly Design
Underground installation substantially reduces noise (≤55dB) and electromagnetic radiation. Surface equipment integrates advertising light boxes with power distribution functions, balancing aesthetics and practicality.
Ultimate Space Optimization
The main body is buried underground, occupying zero ground space, especially suitable for space-sensitive areas like city centers and commercial districts.
Safety and Landscape Integration
Surface equipment integrates LV switch boxes with landscape facilities, minimizing safety hazards while enhancing the urban visual environment.

Technical Specifications

Rated capacity (kVA)	HV (kV)	Tapping range (%)	LV (kV)	Vector group	No-load loss 11#(W)	No-load loss 13#(W)	No-load loss 20#(W)	No-load loss 22#(W)	Load loss 11/13#(W)	Load loss 20#(W)	Load loss 22#(W)	No-load current 11#(%)	No-load current 13#(%)	No-load current 20#(%)	No-load current 22#(%)	Impedance voltage (%)
30	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	100	80	70	65	630/600	505/480	455/430	0.3	0.3	0.24	0.23	4
50	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	130	100	90	80	910/870	730/695	655/625	0.24	0.23	0.24	0.23	4
80	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	180	130	115	105	1310/1250	1050/1000	945/900	0.22	0.18	0.21	0.20	4
100	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	200	150	135	120	1580/1500	1265/1200	1140/1080	0.21	0.16	0.21	0.20	4
125	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	240	170	150	135	1890/1800	1510/1440	1360/1295	0.2	0.15	0.19	0.18	4
160	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	280	200	180	160	2310/2200	1850/1760	1665/1585	0.19	0.14	0.18	0.17	4
200	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	340	240	215	190	2730/2600	2185/2080	1970/1870	0.18	0.12	0.17	0.16	4
250	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	400	290	260	230	3200/3050	2560/2440	2300/2195	0.16	0.12	0.14	0.13	4
315	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	480	340	305	270	3830/3650	3065/2920	2760/2630	0.16	0.11	0.13	0.12	4
400	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	570	410	370	330	4520/4300	3615/3440	3250/3095	0.16	0.11	0.13	0.12	4
500	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	680	480	430	385	5410/5150	4330/4120	3900/3710	0.16	0.1	0.12	0.11	4
630	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	810	570	510	460	6200	4960	4460	0.15	0.09	0.12	0.11	4.5
800	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	980	700	630	560	7500	6000	5400	0.15	0.09	0.1	0.1	4.5
1000	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	1150	830	745	665	10300	8240	7415	0.14	0.09	0.1	0.09	4.5
1250	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	1360	970	870	780	12000	9600	8640	0.13	0.08	0.1	0.09	4.5
1600	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	1640	1170	1050	940	14500	11600	10440	0.12	0.07	0.09	0.08	4.5
2000	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	1940	1360	1225	1085	18300	14640	13180	0.11	0.09	0.09	0.08	5.5
2500	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	2290	1600	1440	1280	21200	14840	13360	0.11	0.08	0.09	0.08	5.5
3150	6,6.3,6.6,10,10.5,11	±5 or ±2×2.5	0.4	Dyn11 or Yyn0	2750	2180			24100			0.11	0.08			6

Applications

It is suitable for installation in basements or cellars, especially in densely populated central cities. It is also applicable to lighting and power systems in streets, highways, bridges, tunnels, parking lots, airports, ports, tourist attractions and other locations. In addition, the underground transformer can be combined with billboards to form a hybrid structure integrating billboards and low-voltage switch boxes, which can be used for public service advertisements, traffic guides, etc.