Overview
The prefabricated compact substation, also known as a package transformer substation or box-type substation, is a fully integrated, factory pre-assembled power distribution system. It houses three functional compartments within a single enclosure.
The high voltage compartment is equipped with an SF6 gas-insulated ring main unit or load-break switches for incoming and outgoing cable connection and transformer protection. The transformer compartment is fitted with either an oil-immersed or a dry-type power transformer, from 50 kVA to 2500 kVA, for voltage step-down. The low voltage compartment houses the distribution equipment.
Because the whole assembly is integrated into one housing and pre-assembled in the factory, it saves over 60% of the footprint compared with a conventional brick-and-mortar substation and reduces on-site installation time by up to 80%.
Key Features
- All-in-one integration — high voltage switchgear, transformer and low voltage distribution are housed in one compact enclosure, saving over 60% of the footprint compared with a conventional substation.
- Factory pre-assembled and tested — pre-assembly reduces on-site installation time by up to 80% and limits human error and weather-related delays.
- Weatherproof enclosure — IP54 or IP55 protection as standard with optional IP65, using anti-corrosion treated steel plates, GRP or colour-coated panels for harsh outdoor environments from -40 °C to +55 °C.
- Modular layout options — multiple configurations are available, including single-row, double-row and L-shape, to adapt to site constraints.
- High safety standards — fully interlocked high voltage compartments, arc-flash protection, pressure relief vents and fire-resistant partition walls between compartments.
- Low maintenance — the sealed transformer uses long-life oil or dry-type cast resin technology, and the SF6 RMU requires no gas replenishment.
- Remote monitoring ready — optional SCADA communication ports on RS485, Ethernet or IoT for real-time data acquisition and fault diagnosis.
- Eco-friendly options — biodegradable ester oil transformers or SF6-free insulated switchgear are available for green projects.
Technical Specifications
| Rated voltage (HV side) | 12 kV / 24 kV / 36 kV (customisable) |
|---|---|
| Rated voltage (LV side) | 400 V / 415 V / 480 V / 690 V (50/60 Hz) |
| Transformer capacity | 50 kVA to 2500 kVA (customisable) |
| Transformer type | Oil-immersed (ONAN) / dry-type (cast resin) / ester oil |
| HV switchgear type | SF6 gas-insulated RMU or solid-insulated load switch |
| LV main breaker | Air circuit breaker (ACB) or moulded case circuit breaker (MCCB) |
| Enclosure protection rating | IP54 / IP55 standard; IP65 optional |
| Enclosure material | Steel plate with polyester powder coating / GRP / aluminium |
| Cooling method | Natural air convection (ONAN); forced air (OFAN) for dry type |
| Operating temperature | -25 °C to +55 °C; cold climate version available |
| Relative humidity | ≤ 95% (non-condensing) |
| Altitude | ≤ 1000 m; higher altitude derating available |
| Standards | IEC 62271, IEC 60076, IEC 60439, GB/T 17467, IEEE C57 (optional) |
| Internal arc | Internal arc fault tested per IEC 62271 |
| Factory certification | ISO 9001, ISO 14001 and OHSAS 18001 |
Typical Configuration
- HV compartment — one RMU with C, F and V modules, with cable sealing ends and lightning arresters.
- Transformer compartment — one 1000 kVA oil-immersed transformer, 12 kV / 0.4 kV, Dyn11, with tap changer.
- LV compartment — one 2000 A ACB main incoming, six MCCB outgoing feeders from 100 A to 630 A, metering CTs and a PFC capacitor bank.
Applications
- Urban power grids — residential communities, commercial plazas, hotels and hospitals.
- Industrial facilities — manufacturing plants, mining sites, oil and gas fields and chemical plants.
- Renewable energy — solar PV farms, wind power stations and battery energy storage systems.
- Infrastructure — airports, seaports, railway traction substations and highway tunnels.
- Temporary and emergency power — construction sites, disaster relief and remote area electrification.
- Telecom and data centres — power backup and distribution for critical loads.
Installation Conditions
- Each substation is delivered with complete factory test reports covering routine and type tests.
- A detailed installation manual, foundation layout drawings, single-line diagrams and wiring schematics are supplied.
- Installation involves preparing a level concrete foundation according to the drawing, lifting and placing the substation by crane or truck, connecting the incoming HV and outgoing LV cables, and connecting the auxiliary power and earthing system.
- Commissioning is performed by the remote team or by local partners.
- For capacities up to 1250 kVA a single-skid design is available; for larger capacities or where road transport is restricted, split-type modules are supplied and assembled on site.
How to Select
- System parameters — HV voltage, LV voltage, frequency and transformer capacity in kVA.
- Transformer type — oil-immersed, dry-type or ester oil.
- HV configuration — RMU with number of incoming and outgoing ways, or load-break switch.
- LV configuration — number of outgoing ways, required current ratings, and whether ATS or PFC is required.
- Environmental conditions — maximum and minimum temperature, altitude, humidity and seismic zone.
- Enclosure preference — material, colour, IP rating and any dimensional restrictions.
- Special accessories — smart IoT monitoring, temperature sensors, fire alarm or remote control panels.
- Example order code — PTS-24-1250-OIL-4W-IP54, being 24 kV, 1250 kVA, oil-immersed transformer, four outgoing LV ways and an IP54 enclosure.
FAQ
What is a package transformer substation?
It is a fully integrated substation in which the high voltage switchgear, the transformer and the low voltage distribution equipment are housed in a single factory-assembled enclosure. It is also known as a prefabricated compact substation or box-type substation.
What transformer capacities are available?
Transformers from 50 kVA to 2500 kVA are available, and the capacity is customisable. Oil-immersed (ONAN), dry-type cast resin and ester oil types can all be fitted.
How much space does it save compared with a conventional substation?
The all-in-one integration saves over 60% of the footprint compared with a conventional brick-and-mortar substation, and factory pre-assembly reduces on-site installation time by up to 80%.
Can it be transported as a single piece?
For capacities up to 1250 kVA a single-skid design is offered. For larger capacities of 1600 kVA and above, or where road transport is restricted, split-type modules are supplied and assembled on site.
Do you offer low-noise versions?
Yes. Acoustic enclosures can be added, or dry-type transformers used, to reduce noise levels below 45 dB(A) for residential areas.
What is the typical lead time?
Standard configurations are available in about four weeks. Custom engineered solutions take six to eight weeks depending on the specification.
Does the substation support remote monitoring?
Yes. Optional SCADA communication ports on RS485, Ethernet or IoT can be provided for real-time data acquisition and fault diagnosis, together with accessories such as smart IoT monitoring, temperature sensors and fire alarm.
What enclosure protection ratings are available?
IP54 or IP55 protection is standard, with IP65 available as an option. The enclosure can be supplied in anti-corrosion treated steel plate, GRP or colour-coated panels, suitable for outdoor environments from -40 °C to +55 °C.
Request Quote
Tell us your specifications, quantity, or application scenario and we will reply with a tailored quote.
