Plenty of project buyers and site electricians run into primary and secondary switchgear, including Compact Switchgear, when handling power‑related jobs. Many people cannot tell them apart, and they end up picking the wrong gear for their power network. This article uses simple everyday language to explain these two units, points out their main gaps, shares real‑project use cases, and gives you straightforward buying advice for your power work.
What Is Primary Switchgear?
Primary switchgear is located immediately after power generators or high-voltage transformers within the power system. It operates at voltage levels starting from 1 kV and can reach up to 36 kV. This equipment has to handle heavy fault current that can exceed 20kA. Most primary switchgear comes with metal-clad housing for strong physical safety. It often connects with SCADA digital protection systems, so workers can monitor and control power conditions from a remote place. Its main job is to take in large-capacity power and pass power onward for further distribution.
What Is Secondary Switchgear?
Secondary switchgear gets installed much closer to end-users. Its common working voltage sits between 11 kV and 24 kV. It deals with lower fault current, usually below 20kA. This kind of gear uses compact modular designs most of the time. RMU cabinets, which many people know as ring main units, are typical examples of secondary switchgear. It takes power from primary equipment and splits power into different local branches to feed nearby loads.
Key Differences Between Primary and Secondary Switchgear
Working Voltage. Primary switchgear supports a wide voltage range from 1kV to over 36kV. It is built for high-level power intake. Secondary switchgear works in a smaller voltage range, mostly from 11kV to 24kV, which fits local power distribution needs.
Fault Current Capacity. Primary switchgear is designed to handle heavy fault current over 20kA. It can resist serious circuit faults in main power lines. Secondary switchgear only needs to manage fault current below 20kA, because it serves smaller and safer power branches.
Installation Location. Primary switchgear is installed near transformers and main power incoming points. It works at the front of the power system. Secondary switchgear is placed close to end users, responsible for final power distribution on site.
Structure and Protection System. Primary switchgear adopts a heavy-duty metal-clad structure and matches SCADA digital protection systems. It offers full safety and remote control. Secondary switchgear uses lightweight, compact modular design with simple local protection, which is enough for regular branch power supply.
Cost and Application. Primary switchgear is much more expensive, and it is used for main power intake and system control. Secondary switchgear costs less, and it mainly distributes power to different branches for daily power use.
Applications of Distribution Switchgear in Real Projects
Distribution switchgear shows up in many different kinds of power projects. Primary switchgear fits heavy-duty sites such as large industrial plants, large-scale power stations and data center power rooms. These places need to receive large power flows and withstand serious short-circuit troubles.
Secondary switchgear finds wide use in residential neighborhoods, commercial buildings and city public power distribution networks. RMU ring-main units are frequently used here. They split power into many small branches to supply local users, and they do not need to deal with very high fault current. Different project sites will mix both types to build a complete and stable power supply network.
How to Choose Between Primary and Secondary Switchgear?
So how do you work out whether you need primary or secondary switchgear for your project? You need to look at a few practical things first. Think about where your equipment will sit inside the whole power network. Check your actual working voltage and the fault-current level your site may meet. Also keep your project budget in mind. You do not want to buy over-specced gear that wastes your money, and you also cannot pick weak equipment that cannot handle your real-world load.
If you still feel confused and cannot make up your mind, share your project details with us. LVMA's electrical engineers will give you practical selection suggestions and send over a full equipment quotation.
About us
Established in 2018, Zhejiang Lvma Electric Co., Ltd. draws on 17 years of electrical engineering expertise. As an ISO 9001:2015-certified enterprise, our primary offerings include intelligent switchgear systems and both oil-immersed and dry-type distribution transformers, exported to Europe, the Middle East, South America, Southeast Asia, and Africa.
Our R&D team holds more than 40 patents, accelerating our progress toward intelligent and sustainable power infrastructure. Through digitalized workflows and continuous condition monitoring, we guarantee stability and safety in every unit delivered.