Medium Voltage Packaged Unit Substations
ENGINEERED TO YOUR UNIQUE SPECIFICATIONS, DELIVERY NEEDS & EXPECTED QUALITY
Premier Customer Service
Detailed Engineering & Technical Support
Industry Leading Lead Times

Fast Response

Flexible Solutions
Dedicated Project Managers
Premier Customer Service
Whether it is for an initial request, products in manufacturing or after sales service. We are here for you. Our experts are available both on- and offline, quick and thorough to respond and ready to answer any question you have
Short Lead Times / Industry Leading Lead Times
Time is almost always of the essence. Our streamlined production and strategically planned supply chain ensures that you get your gear on time, de-risking your project and giving you certainty in execution.
Fast Response
In line with our customer service speed and efficiency are issues important to us. Our fast response time extends to questions, clarifications to any project and service related issue. Unsure which expert is the right one to contact? Not to worry, we will be happy to connect you.
Flexible Solutions
We meet industry standards but are not constrained by standard solutions. If you have specific requests or more uncommon designs we are flexible in accomodating them. Not sure if it will work? Feel free to ask us anything.
Dedicated Project Managers
Ownership and accountability are words we take seriously – and they are reflected in our project management approach: hands on and professional. All our project managers are engineers and many are certified project management professionals. Whether it is the project plan, shopfloor or site, our project managers ensure that everything is in order and on time.
Detailed Engineering & Technical Support
Our gear is designed and built by experts for experts. Our engineering and R&D teams ensure the highest level of support, to meet your specifications and requirements. Value engineering is as important to us as it is to you – we will frequently suggest improvements, when and where they can be made.

We Will Never Force A Solution. We Will Engineer The Answer.
We continually work to create products with higher efficiencies and better value. Each year we make substantial investments in the research & development of new products and manufacturing techniques.
We regularly innovate on behalf of our customers, collaborating with them to find solutions to their specific challenges.


Main Technical Parameters
All the benefits of a standard substation without needing a full civil-designed building. Our packaged substations include fully functional HV/LV switching, control and protection, metering, reactor compensation and more. With the added advantages of small substation footprint, flexibility to move and relocate, low capital investment, unobtrusive and attractive appearance – our packaged substations are designed for use in high-rise buildings, residential districts, municipal facilities, industrial and mining enterprises, oilfields, ports, airports, construction site, roads, wind power plants, etc., and they will work in both indoor and outdoor settings.
Cost
- Civil Cost
- Land (30% space savings)
- Construction Cost
- Time (Decrease of time on site by 40%)
- Material Availability
- Labor Availability
- Overall Cost
- 25% lower than traditional substations
Time
- Quote Lead time
- 3-4 Week Lead Time
- Drawing Lead time
- 3-4 Weeks after receipt of order
- Product Lead time
- 26 weeks after approved drawings
Growth
- Flexibility
- Ability to use multiple inverters and LV technology
- Global Presence
- 1800 Shipped substations
- Factory Control
- Testing and coordination details are handled by (1) OEM
- Quality controlled in Factory setting
- Knowledge and Engineering Capability
MV Equipment | Description | Unit | Parameters | |||
Rated voltage | kV | 7.2 | 15 | 27 | 38 | |
Rated frequency | Hz | 50/60 | ||||
Rated current of main circuit | A | 630 | 1250 | |||
Rated short-time withstand of the main circuit | kA | 20 | ||||
Rated peak withstand current of the main circuit | kA | 50 | ||||
Rated short-circuit duration | S | 3 | ||||
Power-frequency withstand voltage, interphase, ground-to-ground and ordinary fracture/isolating fracture | kV | 32/36 | 43/49 | 95/110 | ||
Lightning impulse withstand voltage, interphase, ground-to-ground and ordinary fracture/isolating fracture | kV | 60/70 | 5/85 | 185/215 | ||
LV Equipment | Rated Voltage | kV | Less than or equal to 1 | |||
Rated current of main circuit | A | 10 - 4000 | ||||
Rated short-time withstand current | kV | 15 | 30 | 50 | ||
Rated peak withstand current | kV | 30 | 63 | 105 | ||
Rated current of branch circuits and number of circuit | Line A | Customized | ||||
Reactive compensation capacity | kVAR | 0 -------- 30% | ||||
Transformer | Rated capacity | kVA | 50 -------- 5000 | |||
Rated voltage on the primary | kV | 3 -------- 35 | ||||
Rated voltage on the secondary side | kV | Less than or equal to 1 (except for power transformation) |

Skid & Container Solutions
The YB-series medium voltage prefabricated substation is a box made up of the HV/LV switchgear, distribution transformer, metering devices for electric energy and compensation devices for power factor, etc., serving as complete sets of power distribution and transformation unit in the power distribution and transformation grid with a rated frequency of 50Hz/60Hz.
Operating Conditions
Maximum temperature: +40°C; minimum temperature: -10°C (ordinary areas) and -25°C (alpine regions)
Enclosure: Rated for outdoor use.
Ground acceleration: Suited for standard and seismic applications.
This product is intended to be installed with predefined conduit entries and an approved surface to support weight. The packaged substation will greatly reduce labor and commissioning time on-site. If any special service conditions are required for installation, inform JST of any requirements. The special service conditions (if any) shall be proposed by and confirmed prior to order placement.
The Model & Meaning
- Model of the box-type substation: YB-□/□-capacity (□ depending on the rated voltage on the HV/LV side)Rated capacity: 30~3,800kVA; if the capacity is larger than 3,800kVA, consult the technicians of the Company to provide a separate scheme.
HV/LV rated voltage: The rated voltage ratio (7.2, 15, 27, 38 generally on the HV side; 0.27, 0.315, 0.4, 0.48, 0.52 and 0.69 generally on the LV side) on the HV and LV side.
Example: YB-15/480-2,500
Transport & Rigging
Easy to handle and easy to transport. Our packaged solutions come with standardized interfaces, such as ISO-container corners, for quick and simple fastening, lifting and rigging. All while remaining within international transport requirements and not requiring oversize transport.
Maintenance & Repair
The electrical equipment (including the switchgear and transformers) inside the product shall be checked and maintained regularly, per the requirements in the installation instructions and relevant provisions. Impact with hard objects should be avoided, as it could damage the anti- corrosion protective coating. The door of the HV/LV switchgear may be opened, or the panel may be removed for ordinary maintenance from the front side. In case of overhaul or replacement of main equipment, the fixed nut of the top cover shall be removed. Lift the top cover away and then lift out the transformer or the switchgear for overhaul or replacement.
Ordering Information
The purchaser shall provide the following data related to the product during ordering:
- Type and capacity of the transformer and configuration of accessories.
- Wiring scheme of the HV/LV chamber and the specifications and model of electrical elements.
- The enclosure is routinely offered in ivory white or in light green. If a special color is needed, provide factory with sample. Customizing is required in case of special color requirements.
- Other client requirements may be requested during ordering.
Transportation
The inclination shall not exceed 30° during product transportation. The vulnerable elements (such as the energy meters) during transportation may be removed before long-distance transportation. Anti-shock packages shall be used separately, and such elements shall be recovered after arriving at the destination. The product shall be placed at the normal usage position during transportation, and the transporting tools shall be fixed firmly to the base or the packing place. The products shall be free from movement and obvious shaking during transportation. Other positions are not allowed except for the hook at the base and the lifting rings at the top.

DEDICATED TEAM
Meet The Experts
“Why JST? Our transformers combine superior quality without compromising on lead time.”
“Our quality is your peace of mind. This promise extends from the initial delivery to when our products are in service. Feel free to send us any after sales service request you may have. We are here to help.”
“Engineered to value – this is reflected in the concise level of detail of our proposals and in the quality of our finished product.”
“We offer expert and end-to-end-support from the moment we receive your request until your switchgear is delivered.”
“Our switchgear is designed and tested according to industry standards, while reflecting best practices and learnings we have gathered as a manufacturer.”
“Are you looking for a quality response on your transformer and switchgear needs? JST is here for you: with our team of experts, proven track record and industry insight.”
Office Headquarters
30 Skyline Drive
Lake Mary, FL 32746
Sales@jstpower.com
Contact Us
+1 407-632-4050
844-631-9046 (Toll Free)