No Load Excitation Oil Immersed Transformer Manufacturers – Off-Circuit Tap Supply
Subian Electric manufactures oil immersed transformers with no-load (off-circuit) tap changers – units that let operators adjust the ratio to match supply conditions when the transformer is de-energised. Our 50,000-square-metre factory in Xuzhou, China, has served 50+ countries since 2019.
As a factory-direct manufacturer and supplier, we build no-load tap changing units from 30 kVA to 63000 kVA with factory pricing and complete documentation.
Send your voltage, capacity and tap range. Our export team will respond with a quotation and technical proposal.


Since 2019 · 50,000m² · 350+ Staff
No Load Tap Changing Oil Immersed Transformers We Manufacture
Oil immersed distribution transformers with off-circuit (DETC) tap changers from 30 kVA to 63000 kVA, with tap ranges confirmed on drawings before production.
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10kV محول جاف - سلسلة SCBH سبائك غير متبلورة
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20-35KV محول جاف
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20-35KV سلسلة SCB محول جاف من راتنج الإيبوكسي
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20KV محول توزيع مغمور بالزيت
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محول طاقة مغمور بالزيت بجهد 35 كيلو فولت
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6-10KV محول توزيع الطاقة مغمور بالزيت
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محول تيار – 10KV عالي الجهد داخلي
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محول تيار–LMZK محول تيار ملفوف 300/5a
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محول تيار–LXK عالي الجهد تسلسل صفري
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محول توزيع جاف - 6-10 KV سلسلة SCB من راتنج الإيبوكسي المصبوب
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المحولات الكهربائية–JDZ – 10 جهد الطاقة
What Is a No Load Excitation Oil Immersed Transformer?
A no load excitation (off-circuit) tap changer adjusts the transformer ratio manually while the unit is de-energised, allowing the voltage to be matched to local supply conditions. It is the economical standard for distribution transformers where voltage is stable.
Off-circuit tap changers are specified across distribution networks where voltage variation is limited. The tap position is set during commissioning and rarely changed, keeping the transformer simple and reliable.
- Off-circuit tap changer – DETC design, ratio adjusted when de-energised.
- 30 kVA – 63000 kVA – complete distribution capacity range.
- 6-132 kV class – voltage classes for grid and industrial duty.
- 50,000m² factory – in-house winding, vacuum drying and testing.
- 350+ employees – engineering, production and export teams.
- OEM / ODM & wholesale – custom branding, packaging and volume supply.
Main Types of Tap Changing Oil Immersed Transformers
We build two tap changer configurations:
No-load (off-circuit) tap changer
Manual ratio adjustment while de-energised – the economical standard for distribution.
Fixed ratio with DETC
A small number of tap positions for fine voltage matching during commissioning.
No Load Tap Changing Transformer Specifications
| المعامل | Specification |
|---|---|
| الجهد المقنن | 6 kV – 132 kV class |
| السعة المصنفة | 30 kVA – 63000 kVA |
| محول التغيير | DETC, ±2×2.5% typical |
| التردد | 50/60 هرتز |
| التبريد | ONAN / ONAF |
| معيار | IEC 60076 / GB 1094 |
Manufacturing No Load Tap Changing Transformers
From winding with tap leads to vacuum drying, oil filling, assembly and testing – every unit is built and tested at our Xuzhou facility.
Production Workshop
Controlled winding, core processing and vacuum drying with quality checkpoints between every stage, so quality is built in from the start.
Quality & Testing Center
Routine inspection on every unit before delivery, with type test reports supporting project approval and market certification.
Materials & Components
Core materials, windings and components are checked against the approved bill of materials on every production run.
OEM / ODM / Agency Supply
Custom branding, packaging and configurations for global partners – from nameplate to complete product design – supported by a dedicated export team.
No Load Tap Changing Transformer Factory Price – Request a Quote
OEM/ODM & Wholesale Supply of Tap Changing Transformers
Distributors can brand or resell units with custom nameplates, packaging and documentation.
OEM / ODM
Factory-Direct
Custom branding, packaging and product variants built on our standard platforms – from a nameplate to full product design.
Custom nameplate · Custom packaging · Full test docs
Wholesale Supply
Volume Pricing
Factory pricing with flexible container quantities, mixed models per container and reliable global shipping for volume buyers and importers.
Container MOQ · Mixed models · Global shipping
Distributor Support
Channel Partners
Dedicated account management, technical documentation and priority production for distributors and project clients.
Account manager · Sales material · Priority lead times
No Load vs On Load Tap Changing Transformers
No-load tap changers are simpler, cheaper and more reliable – the right choice where voltage is stable. On-load tap changers adjust under load for networks with significant voltage variation.
We build both; the selection follows your network’s voltage profile and operational requirements.


Choosing a No Load Tap Changing Transformer Manufacturer
Tap winding quality and connection integrity are the details that matter – verify test evidence and production process control.
Subian Electric offers a 50,000m² factory, 350+ employees, ISO9001, CE and UL certification and export to 50+ countries.
Request a quotation with your voltage, capacity and tap range – we confirm the design before production.
Certifications & Quality Assurance
Our no-load tap changing transformers are produced under ISO9001, ISO14001 and ISO45001 management systems, with CE and UL certification and type test reports.
Product Certifications
No Load Excitation Transformer FAQ
Answers to the questions buyers ask most about off-circuit tap changing transformers.
ما هو محول التبديل بدون تحميل؟
When should I choose a no-load tap changer?
What tap ranges are available?
Can the tap be changed after installation?
What is excitation in a transformer?
What is the minimum order quantity?
Contact Subian
Need the Right Specification?
Tell us your target market, product type, quantity and technical requirements. Our team will help you identify a suitable configuration for your project.










