The switchboard and switchgear are both important systems that control the way power is delivered to electrical circuits. The terms are often used interchangeably. It is important to understand, however, that the switchboard and switchgear each perform different functions. They are typically designed to work together in tandem, to provide maximum protection and co-ordination.
Since both units have different capabilities and functions, they are each suited to different installation types and can be used at different electrical network stages. The decision to use a switchboard, switchgear or both will depend on the requirements and design of the power system in question. To understand where each unit works best, we’ll take a look at their fundamental differences and functions.
A switchgear is a collection of switching devices needed to service low, medium or high-voltage electrical circuits. These devices are needed to switch power on and off for transformers, generators, motors, transmission lines and power networks in domestic, commercial and industrial distribution systems.
Switchgears consist of two main components:
- Power switcher/conducting components like circuit breakers, lightning arresters or fuses which can disconnect power flow when a fault occurs.
- Power control components like control panels, protective relays, and current transformers to protect, monitor, and control power conduction.
Switchboards can come in single panel, assembly panel or structural frame format. They allow incoming electric power to be divided into smaller circuits, depending on requirements. Circuit breakers and overcurrent protection devices should be selected according to the load current.
After the switchboard has divided the currents, these currents are distributed in terms of load (for example, lighting loads or plug sockets). Some switchboards, such as those used in residential settings, come with an option to meter the amount of power used by each individual circuit.
The main components of a switchboard are:
- Panels/frames which hold devices like circuitry indicators and switches to allow the delivery of power or the control of each circuit.
- Control/monitoring devices that connect/control multiple power sources to/from the switchboard. These can include frequency gauges and synchroscopes.
- Busbars to carry/distribute incoming power from its source to different sections of the installation.
Switchgears and switchboards: the differences
The main difference between switchgear and a switchboard lies with the voltage each is designed to handle. Switchgears are designed for high voltages (up to 350 kV) whereas switchboards are designed for voltages below 600V.
Because switchgears are designed for high power handling capacity, they make use of devices like circuit breakers. These circuit breakers can be withdrawn or replaced while the system is still operational. Switchgears operate on mechanisms which enable the connection and subsequent disconnection of electrical power to other circuits or loads. This comprises devices like fuses and relays in addition to circuit breakers.
While a switchboard consists of similar mechanisms as those used in a switchgear system, a switchboard is typically made up of a panel, frame or assembly on which buses, mechanisms and instruments like protective devices and switches are mounted.
Ultimately, the difference comes down to cost. While switchgears are more robust, flexible and reliable than switchboards, they are generally much more expensive.
Understandably, HVAC engineering can be complex. If this seems like an issue best left to the professionals, you might be better asking yourself “are there local engineers or plumbers near me that can help me with my issue?”
If you’d like to know more about the differences between switchgears and switchboards or need help and advice on other issues relating to HVAC electrical engineering, air conditioning repair or heating, and cooling, please do not hesitate to contact our family-run business today.