Pre-Fabricated Substations

Prefabricated substations are an excellent and cost-effective alternative to more conventional brick and mortar buildings. They have evolved from the first pre-manufactured substations, which used standard ISO marine containers. Marine containers still provide an excellent and economical option for many operations but do have limitations in terms of size.

Prefabricated substations – also called E-houses – are built directly according to the specific dimensions of the equipment that will be housed within them. The only limitations come in terms of logistics, and factors such as transportation, crane lifting and port handling facilities. And of course, on-site lifting and handling capabilities have to be taken into account.

In certain instances, where larger E-houses are required, they can simply be built in modular sections and bolted together once on site. When we talk about modular units, we’re generally referring to any electrical power distribution substation that is assembled on a base that is self-supporting, and integrated and tested in a factory environment before being transported to the site for installation and commissioning.

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Benefits of Prefabricated Substations

When compared to the ground-up construction of a conventional substation, prefabricated substations offer a host of benefits that vastly simplify design, installation, commissioning and maintenance:

Streamlined Logistics

Instead of working with separate design and construction personnel, and multiple product manufacturers, prefab substations offer a modern, turnkey solution wth a single vendor responsible for every aspect of the design, procurement of parts, manufacture, installation and commissioning. This means one point of contact and one point of accountability. This consolodation vastly reduces the complexity of the project management and the potential for conflict or miscommunication between vendors.

Saving Time And Money

Prefabricated substations can reduce construction, installation and commissioning times by an average of 50 percent! They can also significantly reduce costs. Imagine if you had to pay for the travel and accommodation costs of all the different – and expensive – experts you’d need to build and commission a substation on site. Installation often requires a number of these experts to all be on site at the same time, which can present significant logistical challenges, especially if you’re in a remote location.

Prefabricated substations also relieve transport problems that can arise from having to ensure numerous deliveries of all the parts needed to construct a substation on site. With a prefabricated unit, there is simply one item to transport.

Reduced Footprint

Prefabricated substations are specifically designed to take up as little space as possible while still meeting all of a project’s specific needs. Because the entire unit fits onto a single platform, transportation and space requirements are significantly simplified. The units can also easily be lifted and relocated if necessary.

Improved Safety

Prefabricated sub-stations contain all equipment and connections inside tamper-proof metal enclosures. There is thus no need for safety fencing, which improves their aesthetic and environmental impact.

Customising Your Substation

Prefabricated substations are designed according to local and international standards, while still meeting specific customer requirements. They also need to take the environmental conditions of the location of the site into account. A number of factors will be considered, including:

  • Total equipment mass
  • Maximum permissible height for transport purposes
  • Thermal insulation required
  • Environmental conditions, such as ambient temperature and air status
  • Cooling requirements for high heat rejection equipment.
  • Cable entry and exit points
  • Fire detection and suppression systems


These factors, and others, dictate how the substation is manufactured. The design must allow for complete interconnectivity between all the electrical equipment so that site control and power cabling is easily achieved.

The Heat Is On

Proper ventilation in prefabricated substations is critical to dissipate the heat produced by the transformers and other equipment. If the transformer is installed in the same enclosure as HV and LV switchgears, it will definitely impact the lifespan of the products. It’s important, however, to get the right balance, as excessive ventilation significantly increases condensation.

Where prefabricated substations are located outdoors, any switchgear should be preferably installed in a thermal insulated enclosure to protect them from environmental factors such as dust, humidity and solar radiation. Ventilation should thus be kept to the minimum amount required, and all ventilation openings should be equipped with chevron blade baffles.

The temperature inside the prefabricated substation should be kept as constant as possible, with variations minimised as much as possible. Anti-condensation heaters may be required in certain cases.

Prefabricated substations from JB Switchgear Solutions comply with IEC standard specifications, providing quality, functionality and operational safety. If you’re looking for a little inside the box thinking, contact us today.