12 KV Substation

The ZGS11-Z-12 10kV American-style prefabricated box-type substation (American-style box-type substation) is a compact, fully sealed, oil-immersed integrated outdoor power distribution device. Unlike the split structure of European-style box-type substations, this product adopts an integrated oil-immersed structure with the high-voltage load switch, current-limiting fuse, and transformer body , while the low-voltage distribution unit is independently and externally sealed. The core configuration of the entire unit includes four main components: a 10kV high-voltage load switch, a 10kV elbow-type pluggable cable head, a fully sealed oil-immersed transformer, and a 0.4kV low-voltage distribution cabinet .

The product features a compact structure, small size, and small footprint, occupying only 1/3 the area of a European-style prefabricated substation of the same capacity. The high-voltage side uses a dedicated American-style elbow-shaped cable head plug-in connection, eliminating exposed live parts and the need for wall bushings. It boasts reliable insulation, waterproofing, anti-fouling properties, and requires no maintenance. The equipment undergoes complete assembly, lubrication, wiring, withstand voltage testing, and overall commissioning at the factory. On-site, only hoisting and cable connection are required for operation; no civil engineering substation construction is needed. This results in a short construction period, low cost, and stable operation, making it widely applicable in 10kV outdoor terminal distribution and distributed photovoltaic grid-connected scenarios.

ZGS11-Z-12 / □

• Z - Modular prefabricated substation
• G - High-protection outdoor structure
• S - Three-phase oil-immersed
• 11 - Type 11 low-loss energy-saving iron core grade
• Z - Terminal power distribution dedicated type
• 12 - The equipment's maximum operating voltage is 12kV, compatible with 10kV power grid systems.
• □ - Transformer rated capacity (kVA), standard specifications: 315, 400, 630, 800, 1000, 1250 kVA

1. Ambient temperature: -30℃～+45℃, can withstand extreme outdoor conditions of high summer temperatures and low winter temperatures;

2. Altitude: ≤1000m; for high-altitude areas, customized solutions with enhanced insulation, anti-condensation, and pressure boosting protection can be provided.

3. Relative humidity: Daily average ≤95%, monthly average ≤90%, no persistent condensation, icing, or frost;

4. Environmental conditions: Outdoor use, with no explosive or corrosive gases, no serious dust or salt spray pollution, and no severe mechanical vibration or impact.

5. Installation site: The site should be flat, with a stable foundation, good ventilation, and unobstructed drainage, free from long-term water accumulation or the risk of waterlogging in low-lying areas.

1. Rated voltage: 10kV (maximum operating voltage 12kV)

2. Low-voltage rated voltage: 0.4kV

3. System rated frequency: 50Hz

4. Transformer rated capacity: 315kVA～1250kVA

5. Rated current of high-voltage load switch: 630A

6. High voltage short-time withstand current: 20kA/2s

7. 10kV elbow cable head: Fully insulated, touch-pluggable type, suitable for 10kV high-voltage access.

8. Rated current of low-voltage main circuit: 630A～2000A

9. Low-voltage short-circuit breaking capacity: 30kA

10. Enclosure protection rating: IP34

11. Cooling method: Oil immersion self-cooling (ONAN)

12. Insulation class: Class A

13. Operating noise: ≤55dB

The 10kV American-style prefabricated substation adopts the industry's classic integrated structure of a front high-voltage plug-in area, a middle oil-immersed main body, and a rear low-voltage independent compartment. It lacks a separate high-voltage cabinet; all high-voltage load switches and current-limiting fuses are built-in and submerged in the transformer tank, resulting in high integration, excellent sealing, and fewer potential failure points. The entire unit is divided into three main functional areas, each with independent functions and interconnected structures, completely distinguishing it from European-style split prefabricated substations.

Standard layout: front-end 10kV elbow cable head high-voltage connection area, middle oil-immersed transformer main body area, rear-end independent sealed low-voltage power distribution area , single-side door operation, ample maintenance space, convenient installation, and minimal footprint.

■ 10kV High Voltage Load Switch (Oil-Immersed Built-in Type)

The high-voltage core of this equipment adopts a 10kV oil-immersed high-voltage load switch , which is completely built into the transformer tank and is constantly immersed in the transformer insulating oil. It relies on the transformer oil for insulation, arc extinguishing, and heat dissipation, exhibiting excellent arc extinguishing performance, stable operation, and requiring no daily maintenance. The equipment is equipped with a built-in current-limiting fuse, forming a classic combination protection mode of load switch + fuse , suitable for 10kV terminal power distribution and photovoltaic grid-connected conditions.

Main functions : It can perform 10kV line opening and closing operations under normal load, and can switch on and off unloaded transformers, unloaded lines and conventional load currents; when a short circuit or overload fault occurs in the system, it can work with the current limiting fuse to quickly cut off the fault, effectively protecting the transformer and downstream low-voltage power distribution equipment; it has power outage isolation and mechanical interlocking functions to ensure the safety of maintenance operations and prevent accidental misoperation.

Structural features : Fully sealed oil-immersed structure, no exposed live parts, moisture-proof, dirt-proof, condensation-proof, extremely weather-resistant outdoors, long mechanical service life, no need for inspection and maintenance during long-term operation.

■ 10kV elbow cable termination (touch-plug type)

10kV elbow plug-in cable head specifically designed for American-style box-type substations. It is a core component that is a hallmark of American-style box-type substations, replacing traditional wall bushings. It is a fully insulated, fully sealed, touch-safe connector with an internal shielding layer, stress cone, and insulating sheath, and is suitable for outdoor high-voltage cable connection installation.

Main functions : Enables quick plugging and unplugging of 10kV high-voltage cables and transformer high-voltage bodies, simplifying wiring and increasing construction efficiency; features a fully insulated and enclosed design with no exposed live parts, effectively preventing electric shock, phase-to-phase short circuits, creepage, and discharge; possesses waterproof, dustproof, anti-aging, and anti-flashover properties, suitable for harsh outdoor environments such as rain, snow, sun exposure, and sandstorms, and can achieve live isolation and segmented maintenance, ensuring extremely high operational safety.

Structural features : easy installation, maintenance-free, high insulation strength, and good shielding performance, completely solving the problems of exposed wiring and susceptibility to moisture and discharge in traditional high-voltage systems.

■ Fully Sealed Oil-Immersed Transformer (Integrated Body)

The transformer is the core transformer unit of the equipment, employing a 10kV S11/S13 series low-loss, fully sealed oil-immersed transformer. The core uses high-permeability silicon steel sheets, and the windings use high-purity oxygen-free copper wire. The entire unit, along with the high-voltage load switch and fuses, is integrated within the oil tank. The equipment is specifically optimized for outdoor load fluctuations and intermittent photovoltaic power generation, featuring overload resistance, impact resistance, stable temperature rise, and low losses. The oil tank adopts an integral welded, fully sealed structure, preventing oil leakage, water ingress, and dust accumulation.

Main functions : It stabilizes and steps down 10kV high-voltage power to 0.4kV standard low-voltage power, providing a stable power supply for downstream power distribution equipment and electrical loads; the oil-immersed self-cooling provides uniform heat dissipation and can operate continuously at full load for a long time, adapting to the long-term stable power generation and distribution needs of the power grid and distributed photovoltaics, with low power generation loss and good operating economy.

■ 0.4kV low-voltage switchgear (independent external compartment)

The low-voltage switchgear adopts an independent external sealed chamber structure, completely isolated from the high-voltage oil-immersed main body, preventing high-voltage faults from affecting the low-voltage system. The switchgear is composed of incoming line cabinets, outgoing line cabinets, metering cabinets, and reactive power compensation cabinets. The main circuit is equipped with frame circuit breakers, and the branch circuits are equipped with molded case circuit breakers. It is equipped with intelligent power meters, energy metering devices, surge protectors, operation indicator lights, and other components. The internal wiring is modular and the layout is neat.

Main functions : It collects 0.4kV low-voltage power output from the transformer to achieve multi-load distribution and voltage stabilization; it has comprehensive protection against short circuit, overload, leakage, lightning surge; it can perform accurate power metering, automatic reactive power compensation, power quality optimization, and real-time monitoring of low-voltage voltage, current, power and other operating parameters to ensure safe, stable and compliant power use on the low-voltage side.

1. Highly integrated: The high-voltage load switch, fuse, and transformer are molded into one piece, eliminating the need for complicated separate cabinets. The structure is extremely simple, with a low failure rate and high reliability.

2. Safe wiring of elbow cable: Fully insulated, touch-pluggable structure, no exposed live parts, protection against electric shock, discharge, water and moisture, and maintenance safety factor far exceeds that of traditional equipment;

3. Compact size and small footprint: It occupies only 1/3 of the area of a European-style box-type transformer of the same capacity, making it suitable for installation scenarios such as corners of communities, roadsides, and areas with limited space.

4. Fully sealed and maintenance-free design: The core high-voltage components are oil-immersed and sealed for protection, with excellent insulation, arc extinguishing and heat dissipation performance, strong outdoor weather resistance, and extremely low maintenance costs in the later stage;

5. Comprehensive protection configuration: high-voltage load switch + fuse combination protection, low-voltage multi-level circuit breaker graded protection, and fast, accurate and reliable fault clearing;

6. Highly efficient construction and installation: The high-voltage cable is plug-in connected, eliminating the need for complex high-voltage wiring procedures. It can be hoisted and positioned on-site for commissioning and operation, significantly shortening the project time.

7. Energy saving and low consumption: Adopting a new generation of low-loss transformers, with low no-load and load losses, the long-term operation has significant energy-saving effect and is suitable for photovoltaic and power grid energy-saving operation requirements.

1. Foundation construction: Pour a flat and solid concrete foundation according to the equipment drawings, reserve cable channels, cable wells and grounding electrode installation positions, and ensure that the foundation is well drained and free from water accumulation.

2. Equipment placement: A professional crane is used to smoothly lift the entire container, level, correct, and fix the equipment to ensure that the container is upright, evenly stressed, and without tilting.

3. Wiring and installation: Connect low-voltage incoming and outgoing cables in accordance with specifications, and accurately insert and disconnect the elbow-shaped cable heads for 10kV high-voltage cables, ensuring proper insulation and sealing protection; reliably connect the entire station grounding system, with equipment grounding resistance ≤4Ω;

4. Overall commissioning: Conduct insulation resistance testing, power frequency withstand voltage testing, protection setting verification, circuit continuity testing, and comprehensively check the insulation sealing of the elbow cable head and the operating status of the equipment;

5. Phased trial operation: First, conduct a no-load trial operation to check for potential problems. If there are no abnormalities, gradually increase the load and operate the equipment. After confirming that the equipment temperature rise, noise, instrument parameters, and protection functions are normal, the equipment can be put into formal operation.

1. During the operation of the equipment while it is energized, non-professionals are strictly prohibited from touching the elbow cable head and high-voltage area. All high-voltage operations must be carried out by a certified electrician in strict accordance with the regulations.

2. Routine inspection: Regularly check the sealing of the enclosure, transformer oil temperature, operating noise, and low-voltage instrument parameters. Pay special attention to whether there is any damage, aging, discharge, leakage, or dirt accumulation in the elbow cable head.

3. Quarterly maintenance: Tighten low-voltage terminals, clean dust and debris from inside the low-voltage cabinet, check the reliability of grounding connections, verify the operation status of protection devices, and check the integrity of cable head insulation sheaths;

4. Annual maintenance: Check transformer oil level and quality, verify the performance of high-voltage protection and low-voltage circuit breakers, comprehensively test the insulation performance of elbow cable heads, and investigate potential aging and loosening of equipment.

1. The equipment should be transported upright throughout the entire process. Tilting, inverting, impacting, and subjecting it to heavy pressure are strictly prohibited. During transportation, rainproof, shockproof, and collisionproof protection should be provided, with special attention to protecting the elbow cable interface from squeezing damage.

2. The equipment should be stored in a dry, ventilated, flat place free from corrosive gases. Avoid long-term exposure to the sun, rain, and sand. For long-term storage, the sealing and insulation of the enclosure should be checked regularly.

1. This product is manufactured, assembled, and tested in strict accordance with national and industry standards. Each piece of equipment undergoes a full range of insulation, withstand voltage, and protective transmission tests before leaving the factory, and can only be shipped after passing the inspection.

2. Product warranty period: 12 months after the equipment is officially connected to the grid or 18 months after delivery (whichever comes first). During the warranty period, non-human-caused damage will be repaired and faulty parts will be replaced free of charge.

3. The manufacturer provides a full range of after-sales services, including on-site hoisting guidance, cable connection and debugging, equipment operation training, and technical support for troubleshooting, to ensure the long-term stable operation of the equipment.