Single-phase cylindrical oil transformer - DH15-50 7.62

Core positioning: This is the DH15-50/7.62 single-phase pole-mounted transformer, with a rated capacity of 50 kVA, designed for 60Hz outdoor applications
Applicable industry: ideal for both residential and commercial applications
Main purposes: This ensures efficient power distribution. It is built to withstand severe weather conditions, mounts on OTTOM brackets, requires minimal maintenance, and is ideal for both residential and commercial applications

product details

Solves the pain point of "excessively long supply radius resulting in low end-of-line voltage

Problem: Traditional three-phase transformers have a limited supply radius. Users far from the transformer (e.g., farmhouses at the end of a long line) experience severely low voltage during peak hours, leading to dim lighting, air conditioners failing to start, and motors running weakly.

Solution: Single-phase pole-mounted transformers can be flexibly installed at the load center or at the end of the line, significantly shortening the supply distance and stabilizing voltage within acceptable limits, ensuring reliable power for remote users.

Solves the pain point of "high no-load losses and electricity costs in low-load areas

Problem: In areas with dispersed housing and low electricity consumption (e.g., individual farms, standalone villas, small workshops), installing a large-capacity three-phase transformer results in significant core (no-load) losses and high basic electricity charges, making it economically inefficient.

Solution: Single-phase transformers typically have smaller capacities (5kVA-100kVA) with much lower no-load losses than three-phase transformers. They only require a single-phase line connection ("small horse pulling a small cart"), significantly reducing basic electricity charges and operational losses.

Product parameters

workshop production

Factory production capacity: annual output of 3,000 transformers

Assembly: 6 shear lines, 15 winding machines, 5 bobbing machines

Test: 220kV Test Hall, Transformer Testing Center

Delivery: Fully automated crane equipment

About the factory

Zhejiang Jiangshan Yuanguang Electric Co., Ltd. was founded in July 2006. The company primarily specializes in oil-immersed transformers, dry-type transformers, and box-type substations below 220KV

We are a qualified supplier of the State Grid and China Southern Power Grid, providing a range of products including stations, photovoltaic and wind power transformers, energy storage box transformers, amorphous alloy transformers, rectifier transformers, electric arc furnace transformers, refining furnaces, and other specialized transformers, as well as complete sets of switchgear equipment. Our products are widely used across various provinces and cities in China and are exported to over 20 countries in Southeast Asia, Africa, and South America.

The company focuses on product research and development, and has established a municipal-level engineering technology research and development center. Currently, the technical team consists of over 20 members, including 1 senior engineer, over 10 professional engineers in electromechanical and electrical fields, and over 20 senior technicians in transformer manufacturing. The company collaborates with Shanghai Second Polytechnic University in industry-university-research cooperation. Its products have obtained UL certification and 3Ci certification in the United States, and some products have obtained the "Made in Zhejiang" certification. The company currently holds 5 authorized invention patents and 33 utility model patents. The company has been awarded honorary titles such as National High-tech Enterprise, High-growth Technology Enterprise in Zhejiang Province, Mayor's Special Award (Export Scale Award), (Technological Innovation Award), Annual Science and Technology Innovation Award, Quzhou Municipal Government Special Award (Enterprise Growth Star Award First Prize), and Specialized, Fine, Unique, and Innovative Small and Medium-sized Enterprises. It is also a harmonious labor relations enterprise in Quzhou City. The company has fully implemented the requirements of the S09001 quality management system, ISO14001 environmental management system, and OHSAS18001 occupational health and safety management system, implemented comprehensive process control, and established a series of management systems for product design, development, production, sales, and service. With the goal of pursuing customer satisfaction, the company serves users and contributes to society

Customer Case

This single-phase transformer is used in our agricultural irrigation applications. With single-phase, two-wire power supply, only two conductors are required, reducing the width of the transmission line corridor by more than half. Tower materials are saved by approximately 40%, significantly reducing the occupation of farmland and making construction coordination much smoother.

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FAQ

Ⅰ. Pressure:

1. What is the rated voltage withstand level of this transformer? What are the power frequency voltage withstand and impulse voltage withstand respectively?

2. Can it operate under full pressure for a long time? Will it affect its lifespan?

3. What is the design lifespan of a pressure vessel? Can it still be used after reaching its lifespan? What inspections are required?

4. Can non-standard pressure ratings be customized? Are there additional fees? What is the delivery time?

5. What pressure levels were tested before leaving the factory? Are there any experimental reports available?

6. Does it have international certifications for pressure vessels, such as ASME, CE, and PED?

7. Can it withstand lightning impulse? Has it undergone lightning impulse testing?

8. What is the overall protection level of the transformer? Can it achieve IP20 for indoor use and IP54 for outdoor use?

II. Fuel consumption:

1. What are the no-load loss and load loss respectively? Are there any actual measurement data?

2. We cannot find the same model of oil product locally. Can you provide the oil product? Or recommend an equivalent local brand as a substitute?

3. At what number of hours is the first oil change due? What are the initial and regular oil change intervals?

4. The fuel consumption suddenly increases, but no leaks can be found. Where should I start checking?

5. What is the fuel/electricity consumption in standby mode?

6. Does long-term low-load operation have any impact on fuel consumption and the equipment itself?

III. After-sales Service:

1. How long is the product warranty period? From which day does it start?

2. What should be done if there is a quality issue within the warranty period? Should it be repaired or replaced for free?

3. How do you provide after-sales service for international customers? Do you have overseas service points?

4. How long does it take from receiving feedback to visiting the customer's home in case of a problem?

5. If it is damaged during transportation, who is responsible? How to claim compensation?

6. If the equipment is damaged due to our improper operation, will you repair it? How much does it cost?

7. Does the shelf life start from the date of shipment, the date of arrival at the port, or the date of acceptance?

8. Can you provide installation and debugging guidance? Should it be done in person or via video/remote?

IV. Delivery Date:

1. Are the standard models available in stock? How long will it take for shipment after the order is placed?

2. What is the typical delivery time for non-standard customization?

3. Can urgent orders be expedited? How is the expediting fee calculated?

5. After placing an order, how long will it take for your production schedule to be arranged? When can we enter the factory for inspection?

6. Can you ship the goods in batches? Ship the urgent ones first, and make up for the rest later?

7. What is the standard for packaging? What level of moisture and rust prevention is achieved? Is it suitable for long-distance sea transportation?

V. Other common supplementary questions:

1. What are the commonly used consumable parts? How many should be prepared for the first time?

2. How can I purchase accessories? Should I procure them domestically or through a local agent?

3. How long will it take for the accessories to be shipped after the order is placed? Will they be shipped via express delivery or together with the bulk goods?

4. Will using non-original accessories affect the warranty?

5. Can you provide a list of accessories, exploded views, and part numbers?

6. If the parts are not available in the local market, can you ship them directly to overseas?

7. What is the production capacity of your factory? Can you undertake large-scale bidding projects?

8. Can we discuss the payment method? T/T, L/C, or is OA credit sale possible?

Understand knowledge

Environment and installation method:

Oil-immersed vs. Dry-type: Oil-immersed transformers have good heat dissipation and low cost, making them suitable for standalone substations; dry-type transformers have excellent fire resistance, making them suitable for indoor or underground garages and other places with high fire safety requirements.

Special Environment: In corrosive environments such as coastal areas or chemical plants, the box body should be made of C5-M grade anti-corrosion materials and pass the salt spray test. In high-altitude areas (>1000m) or extremely cold regions (-40℃), special formulated insulating oil and heat dissipation structures are required.

Voltage and energy efficiency:

Multi-voltage adaptation: For example, American transformers often use dual primary windings, connected in parallel in 120V systems and in series in 240V systems. When wiring, it is important to pay attention to the polarity markings (phase points), as reversing them can lead to short circuits and burnouts.

Energy efficiency standards: Pay attention to new national energy efficiency standards such as GB 20052-2024. If you are pursuing ultimate energy saving, you can consider amorphous alloy core transformers, whose no-load loss can be reduced by more than 75% compared to traditional silicon steel sheets, making them suitable for long-term no-load or light-load operation scenarios

Operation and maintenance: Daily and weekly inspections: The main focus is on "listening, observing, and measuring".

Listen to the sound: The normal operation should produce a uniform "buzzing" sound. If there is a "squeaking" discharge sound or severe noise, immediate troubleshooting is required.

Check the oil temperature and oil level (oil-immersed type): It is recommended that the upper oil temperature not exceed 85℃ (conventional temperature rise limit). If it exceeds 95℃ during routine inspections, an alarm should be triggered. The oil level should be within the specified scale mark, and the oil color should be normal.

Key inspection points: Check the porcelain insulator for any discharge marks, and inspect the busbar and connection points for any abnormal heating.

Regular maintenance (monthly/biannual):

Insulation testing: The insulation resistance values between coils and to ground should be measured every six months, and the neutral grounding resistance should be checked.

Tap changer maintenance: On-load tap changers are prone to frequent malfunctions. After being switched a certain number of times (usually 100,000 times or as specified by the manufacturer), they need to be replaced or overhauled.

Protection device verification: Check whether the gas relay is fully filled with oil, and the gas relay of the on-load tap changer should be vented once a month

Industry knowledge: Intelligent operation and maintenance: Modern transformers are integrating fiber optic sensing and digital twin technology. By monitoring dissolved gases in oil, partial discharge, and vibration in real time, combined with AI algorithms, fault early warning can be achieved (with an accuracy rate of up to 98%), transforming traditional reactive maintenance into predictive maintenance and reducing operation and maintenance costs.

New energy scenario: Given the volatility of photovoltaic and wind power, grid-forming transformer technology has become a hot topic. It can maintain grid connection for more than 1.5 seconds when the grid voltage drops by 20%, providing inertial support to the main grid and solving the problem of stable operation under weak grid conditions

Application advice: Rectifier circuit application: In DC power supply equipment, avoid directly selecting based on sine wave current. Pulsed current will increase winding loss. It is recommended to choose a transformer with low DC resistance (i.e., low copper loss) and a higher power rating to handle surges.

Ventilation and spacing: When installing in pump stations or distribution rooms, it is not advisable to install equipment close to the walls in order to save space. A ventilation distance of at least 1.5 times the diameter should be ensured, and lighting or power lines must not be crossed above oil-immersed transformers to prevent a chain reaction of fires.

Parallel operation: When two transformers need to operate in parallel, it is necessary to strictly meet the conditions of having the same connection group, equal voltage ratio (with an allowable error of ±0.5%), and similar impedance voltage (short-circuit impedance) (with an allowable error of ±10%). Otherwise, it may cause circulating current and burn out the windings.

Strictly prohibit reverse power transmission: It is strictly prohibited to use ordinary step-down transformers for reverse voltage boosting. Due to their design, which is close to the magnetic saturation point, reverse voltage boosting can lead to severe saturation of the magnetic core, generating a large excitation current that can cause the winding to melt within seconds.

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